Article Search
검색
검색 팝업 닫기

Metrics

Help

  • 1. Aims and Scope

    Gut and Liver is an international journal of gastroenterology, focusing on the gastrointestinal tract, liver, biliary tree, pancreas, motility, and neurogastroenterology. Gut atnd Liver delivers up-to-date, authoritative papers on both clinical and research-based topics in gastroenterology. The Journal publishes original articles, case reports, brief communications, letters to the editor and invited review articles in the field of gastroenterology. The Journal is operated by internationally renowned editorial boards and designed to provide a global opportunity to promote academic developments in the field of gastroenterology and hepatology. +MORE

  • 2. Editorial Board

    Editor-in-Chief + MORE

    Editor-in-Chief
    Yong Chan Lee Professor of Medicine
    Director, Gastrointestinal Research Laboratory
    Veterans Affairs Medical Center, Univ. California San Francisco
    San Francisco, USA

    Deputy Editor

    Deputy Editor
    Jong Pil Im Seoul National University College of Medicine, Seoul, Korea
    Robert S. Bresalier University of Texas M. D. Anderson Cancer Center, Houston, USA
    Steven H. Itzkowitz Mount Sinai Medical Center, NY, USA
  • 3. Editorial Office
  • 4. Articles
  • 5. Instructions for Authors
  • 6. File Download (PDF version)
  • 7. Ethical Standards
  • 8. Peer Review

    All papers submitted to Gut and Liver are reviewed by the editorial team before being sent out for an external peer review to rule out papers that have low priority, insufficient originality, scientific flaws, or the absence of a message of importance to the readers of the Journal. A decision about these papers will usually be made within two or three weeks.
    The remaining articles are usually sent to two reviewers. It would be very helpful if you could suggest a selection of reviewers and include their contact details. We may not always use the reviewers you recommend, but suggesting reviewers will make our reviewer database much richer; in the end, everyone will benefit. We reserve the right to return manuscripts in which no reviewers are suggested.

    The final responsibility for the decision to accept or reject lies with the editors. In many cases, papers may be rejected despite favorable reviews because of editorial policy or a lack of space. The editor retains the right to determine publication priorities, the style of the paper, and to request, if necessary, that the material submitted be shortened for publication.

Search

Search

Year

to

Article Type

Review Article

Split Viewer

Genetic Risk Factors for Metabolic Dysfunction-Associated Steatotic Liver Disease

Yiying Pei1,2 , George Boon-Bee Goh1,2

1Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore; 2Medicine Academic Clinical Program, Duke-National University of Singapore (Duke-NUS) Medical School, Singapore

Correspondence to: George Boon-Bee Goh
ORCID https://orcid.org/0000-0001-8221-5299
E-mail goh.boon.bee@singhealth.com.sg

Received: September 23, 2024; Revised: November 4, 2024; Accepted: November 7, 2024

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Gut Liver 2025;19(1):8-18. https://doi.org/10.5009/gnl240407

Published online January 8, 2025, Published date January 15, 2025

Copyright © Gut and Liver.

Metabolic dysfunction-associated steatotic liver disease (MASLD), is the most common cause of liver disease, and its burden on health systems worldwide continues to rise at an alarming rate. MASLD is a complex disease in which the interactions between susceptible genes and the environment influence the disease phenotype and severity. Advances in human genetics over the past few decades have provided new opportunities to improve our understanding of the multiple pathways involved in the pathogenesis of MASLD. Notably, the PNPLA3, TM6SF2, GCKR, MBOAT7 and HSD17B13 single nucleotide polymorphisms have been demonstrated to be robustly associated with MASLD development and disease progression. These genetic variants play crucial roles in lipid droplet remodeling, secretion of hepatic very low-density lipoprotein and lipogenesis, and understanding the biology has brought new insights to this field. This review discusses the current body of knowledge regarding these genetic drivers and how they can lead to development of MASLD, the complex interplay with metabolic factors such as obesity, and how this information has translated clinically into the development of risk prediction models and possible treatment targets.

Keywords: Metabolic dysfunction-associated steatotic liver disease, Genetic, PNPLA3, Risk stratification, Treatment

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is now the most common chronic liver disease globally,1 with an ever growing prevalence, increasing from 25.3% in 1990–2006 to 38% in subsequent period of 2016–2019.2 Defined by the presence of hepatic steatosis in conjunction with metabolic dysfunction, MASLD includes a wide spectrum of clinical phenotypes, from simple steatosis, steatohepatitis, to fibrosis and ultimately cirrhosis. Recognizing the high prevalence and natural history profile of MASLD, the anticipated disease burden in years to come is of great concern.3 Modelling studies project increasing incidences of hepatocellular carcinoma (HCC), decompensated cirrhosis and MASLD-related mortality by 2030.4 All this contributes to the bourgeoning socio-economic health burden worldwide from both the clinical and public health perspectives.5-7

As MASLD is usually clinically asymptomatic and insidious, awareness and insight regarding perceived risk may not seem so evident.8 As such, it remains critical for continued efforts to highlight MASLD amongst all stakeholders, including associated risk factors.

The bi-directional relationship between MASLD and metabolic factors has been well established. With advances in human genetics over the past few decades, our understanding of the multiple pathways, interactions and contributions between the various factors involved in the pathogenesis of MASLD continue to evolve and provide new opportunities in innovative research.9 Here, we will be focusing on genetic risk factors, which represent significant factors at play in MASLD. Besides potentially identifying at risk individuals at a deeper level, genetic profiling may also allow development of novel biomarkers and targeting of specific gene pathways in a personalized precision medicine approach.

Genetic and epidemiological studies have indicated strong heritability of hepatic fat.10 This evidence comes from familial aggregation studies that demonstrated that first-degree relatives have up to 12-fold increased risk of MASLD compared to the general population.11 Another study performed in 2009 revealed that MASLD was more common in siblings (59%) and parents (78%) of children with MASLD, despite adjustments for age, sex, race, and body mass index (BMI). Separately, twin studies suggest between 35% and 61% hereditability for MASLD.12 Multi-ethnic cohorts also highlight major inter-ethnic variability in MASLD susceptibility, proving that the risks are higher in Hispanics, intermediate in Europeans and lower in individuals of African descent, independent of confounders.13

The risk is not limited to the diagnosis of MASLD but also to poorer liver-related outcomes. A recent nationwide multigenerational cohort study performed in 38,000 Swedish adults who are first-degree relatives of patients with biopsy proven MASLD found that the rate of HCC, major adverse liver outcomes, and liver-related mortality was 1.8 times, 1.52 times, and 2.14 times higher respectively than comparator first-degree relatives, illustrating a distinct familial clustering.14

Genome-wide association studies (GWAS) cemented the awareness and importance of genetic factors in the pathogenesis of MASLD, and opened up exciting new opportunities to address the unmet need for therapeutics in MASLD. In the age of precision medicine, the identification of patients with specific gene variants may allow individual and targeted treatment via specific genetic pathways.

While there are many genetic factors reported in the literature to be associated with NAFLD,15 and more recently MASLD,16 the most well studied and strongest association has been suggested in the following five single nucleotide polymorphisms (SNPs) as summarized in Table 1. These five genes known to be associated with MASLD are all involved in glucose and fat homeostasis regulatory pathways as illustrated in Fig. 1.

Figure 1.Genetic loci involved in the susceptibility and pathophysiology of fatty liver disease. PNPLA3, patatin-like phospholipase domain-containing protein 3; HSD17B13, hydroxysteroid 17-beta dehydrogenase 13; VLDL, very low-density lipoprotein; APOB, apolipoprotein B; MBOAT7, membrane bound O-acyltransferase domain-containing 7; GCKR, glucokinase regulator; TM6SF2, transmembrane 6 superfamily member 2; MASLD, metabolic dysfunction-associated steatotic liver disease.

Table 1. Genetic Variants Associated with MASLD

GeneGenetic variantAffected proteinEffectPathophysiologyEffect on hepatic steatosisEffect on NASHEffect on fibrosis/cirrhosisEffect on HCCMortalityReference
PNPLA3rs738409 C>GI148M

Complex

Gain of function and also loss of function

Lipid droplet remodeling18-24
TM6SF2rs58542926 G>AE167KLoss of functionInhibits secretion of VLDL in hepatocytes-25-29
MBOAT7rs641738 C>TLysophosphatidylinositol-acyltransferase 1 (LPIAT1)DownregulationPhospholipid remodeling-30-33
GCRK

rs780094 C>T

rs1260326 C>T

Intronic variant

P446L

Loss of functionIncreases de novo lipogenesis--34-37
HSD17B13*rs72613567 T>TASplice donor variantLoss of functionLipid droplet remodeling-38-41

MASLD, metabolic dysfunction-associated steatotic liver disease; NASH, nonalcoholic steatohepatitis; HCC, hepatocellular carcinoma; VLDL, very low-density lipoprotein.

*There are many variants within the HSD17B13 gene, including rs6834314 A>G, rs62305723 G>A, rs10433937 T>A, T>C, T>G, rs10433879 G>C, rs61748262 C>A, C>T.



1. Patatin-like phospholipase domain-containing protein 3

With the first reported landmark GWAS study in context of MASLD by Romeo et al. in 2008,17 patatin-like phospholipase domain-containing protein 3 (PNPLA3) variant was found to be associated with increased hepatic lipid content. The variant is a cytosine to guanine substitution that results in an isoleucine to methionine substitution at position 148 in PNPLA3 gene (rs738409). Subsequent studies have confirmed that this is the most robust, well-replicated genetic variant associated with MASLD.42 Furthermore, inter-ethnic variability in MASLD is likely accounted for by PNPLA3. Illustrating this, the PNPLA3 allele (rs738409[G], encoding I148M), which was strongly associated with increased hepatic fat levels was found most commonly in Hispanics, who in turn, epidemiologically have the highest susceptibility to MASLD.17

PNPLA3 codes for a triacylglycerol lipase that mobilizes polyunsaturated fatty acids from triglycerides. This facilitates the liver’s ability to secrete large-sized very low-density lipoprotein (VLDL), which transports triglycerides from the liver to other tissues.43,44 The current understanding is that the genetic variant is possibly inducing both a gain- as well as a loss of function effect. A loss of function of this allele can hinder the formation and secretion of VLDL,45 further contributing to triglyceride accumulation in the liver because the liver is less able to export the excess fat.46,47

The I148M mutant of PNPLA3 tends to accumulate on the surface of lipid droplets.48 Recent studies have shown that this protein mutant suppresses adipose triglyceride lipase-mediated lipolysis,49 by competing for the co-activator comparative gene identification-58 at the surface of the lipid droplets.46 This gain of function mutation involving transrepression of adipose triglyceride lipase results in impaired lipid turnover and results in accumulation in hepatocytes.50 Impairment of retinol release from the lipid droplets of hepatic stellate cells resulting in an inflammatory response and fibrogenesis in carriers of the PNPL3 I148M has also been suggested as a contributory mechanism.51

Clinically, it is associated with rise in hepatic fat content,18,52 elevated liver enzymes, fibrosis,19-21,53 cirrhosis and HCC,22,23 carrying an odds ratio of 1.91 for MASLD, 2.54 for metabolic dysfunction-associated steatohepatitis (MASH), and 2.68 to 5 for HCC.24,25 In keeping with these findings, PNPLA3 was also found to be associated with the risk of hepatic decompensation (hazard ratio, 2.1), liver-related mortality (hazard ratio, 3.64)24 as well as overall mortality.54

Interestingly, this effect is independent of alterations in glucose homeostasis or lipoprotein metabolism.17,24 There is also no association of this variant with BMI, triglyceride levels, high and low-density lipoprotein levels, or diabetes.17,55 This may be related to the dissociation between the PNPLA3 genetic variant with insulin resistance, estimated from oral glucose tolerance test and measured by the euglycemic-hyper insulinemic clamp.56 This has led to the postulation that the effect of PNPLA3 variant on the degree of hepatic steatosis is not related to insulin sensitivity or resistance, but rather that it sets off a multi-step process that is more subtle, sensitizing the liver to metabolic stress due to nutritional calorific excess.57 In mouse models, PNPLA3 expression is upregulated by carbohydrate feeding through the liver X receptor/sterol regulatory element binding protein-1c pathway.58 Thus, loss of function of this gene under lipogenic conditions provides a potential explanation for the increased susceptibility of patients carrying the I148M variant to the development of liver steatosis and MASLD.49 This can also be seen in how morbid obesity acting as a stressor on a specific genetic background may influence susceptibility to MASLD.57,59 An Italian genetic association analysis found that morbidly obese patients carrying the PNPLA3 148M allele have increased levels of alanine transaminase and aspartate transaminase without any differences in insulin sensitivity or glucose tolerance.60 This shows that patients with obesity will have a more extreme liver injury with the PNPLA3 148M allele than lean individuals.61 Among lean persons (BMI <25 kg/m2), hepatic steatosis in the MM homozygous individuals was at 2.8% versus 1.8% in the II homozygous individuals, whereas in those who were obese (BMI >35 kg/m2), hepatic fat was 14.2% versus 4.7% in MM than in II individuals, demonstrating that the effect of the M variant increased with increasing BMI.59 This finding was also replicated in an Asian (Hong Kong) population which found that the median intrahepatic triglyceride increased only mildly in the lean group (1.5% in wild type vs 2.8% in homozygotes), but tripled in the obese subgroup (4.7% in wild type vs 14.2% in homozygotes).62

2. Transmembrane 6 superfamily member 2

Transmembrane 6 superfamily member 2 (TM6SF2) regulates the hepatic VLDL secretion pathway.26 The G to A substitution encoding glutamate to lysine substitution at position 167 at the rs58542926 SNP results in loss of function in the hepatic VLDL secretion pathway, inducing higher liver triglyceride content, resulting in increased susceptibility to liver damage.27

This impairment in cholesterol metabolism leads to increased liver fat content, MASH, advanced fibrosis and cirrhosis,28,63 and even HCC in mouse models,27 with allelic odds ratio of 1.82 for MASLD and 1.37 for MASH.25,29 This genetic variation associated with advanced hepatic fibrosis is independent of potential confounding factors such as age, BMI, type 2 diabetes mellitus (T2DM) and PNPLA3 rs738409 genotype.28,63 While this genetic variant has a moderate to large effect size, it is a generally low frequency variant, and shows inter-ethnic variations in its carriage.64

Of note, it is associated with a lower cardiovascular risk, postulated to be due to diminished circulating levels of cholesterol and lipids65 because these instead accumulate in the liver.62,63 It has been suggested that TM6SF2 controls hepatic lipid efflux, as loss of function of the gene results in a reduction in lipoprotein secretion (VLDL, triglyceride [TG], and apolipoprotein B), which leads to increased hepatocellular lipid droplet size and TG accumulation in the liver.66 This variant has also been related to the development of T2DM.67

3. Membrane-bound O-acyltransferase domain-containing 7

Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7) encodes lysophosphatidylinositol-acyltransferase 1, which is involved in incorporating arachidonic acid and other unsaturated fatty acids into lysophospholipids, producing a component of cell membranes called phosphatidylinositol.68 The rs641738 SNP variant linked to 3’UTR of MBOAT7 is associated with the downregulation of MBOAT7, which reduces levels of phosphatidylinositol-containing arachidonic acid and increases levels of saturated lysophosphatidylinositol.30 This is a proinflammatory molecule involved in macrophage and endothelial cell activation and induces de novo lipogenesis and inhibits beta oxidation in hepatocytes. The downregulation of this gene also favors the accumulation of free arachidonic acid, a known driver of hepatic inflammation.31,69,70

This variant is linked with an increased risk of MASLD, inflammation, fibrosis, and HCC.31,32 It carries allelic an odds ratio of 1.15 (95% confidence interval [CI], 1.05 to 1.26) for MASLD, 1.24 (95% CI, 0.81 to 1.90) for MASH, 1.2 (95% CI, 1.02 to 1.42) for advanced fibrosis and 1.4 (95% CI, 0.99 to 1.98) for HCC.33 However, the effect size is small compared to PNPLA4 and TM6SF2. No effect on fasting insulin levels was found in population-level GWAS (β=0.009 [95% CI, –0.03 to 0.04], pz=0.6461), indicating lack of an effect of rs641738C>T on insulin resistance.33

4. Glucokinase regulator

Glucokinase regulator (GCKR) is an inhibitor of glucokinase (GCK), and its hepatic concentration is increased in MASLD. The GCKR gene is involved in the glucose control and metabolism in hepatocytes.71 The rs780094 C>T gene variant has been shown to be related to hepatic steatosis not just in adults,34 but another loss of function variant rs1260326 C>T SNP was even associated with increased risk of MASLD in obese children and adolescents.35 The SNP rs1260326 results in a loss of function variant that increases de novo lipogenesis by inducing glycolytic influx and glucose uptake.72 GCK, which is inhibited by the GCKR protein, catalyzes the beginning of the glycolytic pathway. With the P446L GCKR variant, this inhibition is reduced, resulting in increased activity of GCK, promoting the glycolytic pathway and elevating concentrations of a precursor for fatty acid biosynthesis, leading to the accumulation of hepatic lipids.73 This gene is associated with MASLD, MASH, and HCC with allelic odds ratio of 1.38 to 1.49 for MASLD,36,37 1.5 for MASH, and 1.52 for fibrosis.37

5. Hydroxysteroid 17-beta dehydrogenase 13

Hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) is a hepatic lipid droplet protein which is involved in steroid hormone signaling as well as lipid droplet remodeling,74 and has multiple polymorphisms including rs72613567 SNP variant, rs143404524, rs62305723. All these variants alter genetic splicing that results in truncated or stable HSD17B13 proteins that have a marked loss of enzymatic activity that protect against liver injury,38,39 including MASH, ballooning, lobular inflammation and fibrosis. The allelic odds ratios have been reported to be 0.84 for MASLD, 0.86 for MASH, and 0.67 to 0.77 for HCC,25,40 and each minor allele has been found to decrease the risk of cirrhosis and cirrhosis-associated mortality by 15% (95% CI, 0.74 to 0.98) and 49% (95% CI, 0.32 to 0.81), respectively.41 The protective role seems to be associated with retinol metabolism, via retinol dehydrogenase activity, inflammation and fibrogenesis rather than simply lipid accumulation in the liver.75

Another exciting finding was that rs72613567 interacted with PNPLA3 I148M, mitigating the effects of liver injury as well as that of advanced fibrosis.76 However, the effect may be influenced by the presence of other factors, as a recent analysis found that the protective effect of HSD17B13 rs72613567 was significant only in selected subgroups of individuals–those aged ≥45 years, women and have class ≥2 obesity or diabetes, and those with PNPLA3 rs738409 CC genotype.77

Given the high effect sizes and genotypic variability associated with MASLD, there was optimism that precision medicine would be translatable to develop new drug targets as well as biomarkers to treat and/or predict MASLD and its liver-related events. Unfortunately, to date, none of the known variants, despite being widely studied, have successfully transitioned into established clinical use. Improvement in risk stratification and development of effective therapies for fatty liver disease remain key unmet clinical needs. Nevertheless, knowledge emerging from genomics could meet this need via use of polygenic risk scores for early disease detection and stratification of severity of fatty liver disease.

1. Risk stratification

There are studies in progress studying the use of these genetic variants as part of risk prediction models.

Bianco et al.78 were able to predict HCC using a polygenic risk score in a European cohort based on PNPLA3, TM6SF2, GCKR, MBOAT7–common genetic variants associated with hepatic fat content (PRS‐HFC), and thereafter further adjusted for HSD17B13 as well, in a second score called PRS‐5. They showed that the PRS-HFC was significantly associated with increased risk of HCC, estimated to be around 3-fold, in the MASLD cohort, though diagnostic accuracy was only moderate (Table 2).78 These results have also been shown to be useful in an Asian population.79 The potential ability to predict HCC was verified with the HCC risk prediction score that was able to identify at risk patients with an area under the curve (AUROC) of 0.96.32

Table 2. Risk Prediction Scores for Liver-Related Outcomes

ScoreGenetic variant and components of scoreMethodCohortPredicted outcomeAUROCDiagnostic thresholdOdds ratioSensitivitySpecificityReference
Genetic risk scorePNPLA3, TM6SF2, HSD17B13Blood testGeneral (European) population

Cirrhosis

HCC

NACombined GRS calculated as sum of risk-increasing alleles with range: 0-6

Up to 12 for cirrhosis

Up to 29 for HCC

NANA82
Cirrhosis polygenic risk scorePNPLA3, TM6SF2, HSD17B13, MBOAT7, GCKR, TRIB1, APOE, GPAMBlood testNAFLD with diabetes and indeterminate FIB-4 (1.3–2.67)Cirrhosis or portal hypertensive complications0.73NANANANA80
PNPLA3-rs738409-GG genotypePNPLA30.78Presence of GG genotypeNA0.300.93
HCC risk score*Age, sex, obesity, T2DM, severe fibrosis, number of risk alleles (PNPLA3, TM6SF2 MBOAT7)Composite score with clinical, metabolic and genetic factorsNAFLDHCC0.96NA13.40.960.8932
Polygenic risk score–hepatic fat content (PRS-HFC)PNPLA3, TM6SF2, MBOAT7, GCKRBlood testNAFLDHCC0.640.5323.00.430.8078
Polygenic risk score considering 5 risk variants (PRS-5)PNPLA3, TM6SF2, MBOAT7, GCKR, HSD17B13Blood testNAFLDHCC0.650.4952.90.430.7978
Genetic and Metabolic Staging (GEMS) scoring system

PNPLA3, HSD17B13, TM6SF2, male sex,

diabetes, low HDL

Composite score of clinical, metabolic and genetic variablesNAFLD and FIB-4 ≥ 1.3Liver-related events0.87

Range from 0 to 10

0=total absence of risk of LREs 10=highest risk of LREs, then sub-categorized into five classes: 0–5, 5–6, 6–7, 7–8, 8–10

Risk of LREs increased from 4% in GEMS 0–5, to 91% in GEMS 8–10NANA81

AUROC, area under the curve; HCC, hepatocellular carcinoma; NA, not available; GRS, genetic risk score; NAFLD, nonalcoholic fatty liver disease; FIB-4, fibrosis-4 score; T2DM, type 2 diabetes mellitus; HDL, high-density lipoprotein; LRE, liver related events.

*A combined risk score considering acquired and genetic risk factors was developed to predict HCC: 1/(1+e− ((−12.588+(0.162×age)+(0.404×sex: 1 if male, −1 if female)+(0.259×obesity: 1 present, −1 absent)+(0.587×T2DM: 1 present, −1 absent)+(1.299×severe fibrosis: 1 yes, −1 no)+(0.442×number of risk alleles))); The GEMS score is calculated using the following formula: 1.163–0.438(PNPLA3 CG/GG)+0.421(male sex)–0.413(diabetes)+2.635(55≤age<65)+2.888(age>65)+0.632(low HDL)+0.668(albumin <4 g/dL)+1.935(110,000/mm33)+2.605(platelets<110,000/mm3)+0.602(HSD17B13 TTA/TATA)+0.661(TM6SF2 CT/TT)–1.146(interaction PNPLA3 CG/GG and male sex)+1.641(interaction PNPLA3 CG/GG and diabetes).



Looking beyond HCC, risk scores incorporating genetic variables have also been able to predict incident cirrhosis in patients with NAFLD.80 The Genetic and Metabolic Staging score incorporates genetic variants with clinical and biochemical parameters to predict liver-related events within the MASLD advanced fibrosis cohort with an AUROC of 0.87 at 1, 3, and 5 years.81 However, the AUROC drops to 0.7 when applied to the general population, which marks it as suboptimal as a screening tool,81 though other studies have been promising: a genetic risk score comprising three common variants in PNPLA3, TM6SF2 and HSD17B13 has shown an association of up to 12-fold higher risk of cirrhosis and up to 29-fold higher risk of HCC.82 This shows that such genetic scores may have the potential to predict the onset and progression of chronic liver disease in the general population. Vicenti and colleagues have also looked into combining the PRS-HFC score with noninvasive fibrosis scores such as NAFLD fibrosis score and fibrosis-4 to improve prediction of cirrhosis and liver events in the overall population.83 Genetics can possibly even predict liver-related mortality, as the genetic variant PNPLA3 I148M has been found to be associated with increased liver disease mortality with a hazard ratio of 18.2.54

Overall, the current evidence suggests that genetic testing does have potential in identifying MASLD patients at higher risk of developing liver‐related events including HCC, and even of mortality, though challenges remain in the overall ability to extrapolate use of such tests in the general population.

2. Treatment

Even as the space for therapeutics for MASLD remains exciting with recent new findings, the cornerstone for MASLD treatment remains lifestyle modifications.

Data suggests that genetic variations can also affect efficacy and response to lifestyle modification and exercise in MASLD. The presence of G allele in PNPLA3 rs738409 gene polymorphism was associated with greater reduction in intrahepatic TG, body weight, waist-to-hip ratio, blood total cholesterol, and low-density lipoprotein levels in MASLD patients who were enrolled in a 12-month community-based lifestyle modification program.84 However, there was contrasting findings in a Japanese cohort that found greater reduction in body weight in MASLD patients with the c allele of PNPLA3 rs738409 rather than the G allele.85 This difference could be accounted for by the lower body weight reduction in the Japanese study, where the dietary intervention is described only as a consultation at baseline visit, as compared to a more intensive regime and personalized meal plan performed by the study by Shen et al.84 Interestingly, the impact of the G allele may be restricted beyond a minimum amount of weight loss. A closer look at the results from the Japanese study yields the finding that among patients with a body weight loss of more than 5%, the reduction of liver stiffness measurement was significantly greater according to the predominance of the G allele. The patient population amongst these two studies also may not be comparable given the higher percentage of advanced fibrosis in the Japanese study, and may suggest that the benefit of the G allele in PNPLA3 rs738409 gene polymorphism may be restricted to early intervention, prior to progression to advanced fibrosis, beyond which the impact may be lost or becomes minimal.

Genetic profiles may also be helpful in predicting response to therapy, which can guide the development of potential therapeutics. A study looking at treatment of NAFLD with silymarin – vitamin E combination was able to produce a decrease in transaminases, but PNPLA3 G-allele carriers responded poorly to the treatment.86 In patients with T2DM, treatment with exenatide improved liver fat content in patients carrying PNPLA3 148I/I better than in patients with 148M/M.87 Genetic modulation of therapeutic responses indicates that a genetic-based approach may be the way forward. Having genetically supported drug targets increases the likelihood of successful clinical development by 2-fold.88 With recent success of drug development in atherosclerosis therapy, such as the PCSK9 story, which was rooted in discovery of drug target based on genetic profiling,89 optimism persists that similar approaches can be applied to MASLD. Indeed, oligonucleotide-based therapies in the form of antisense oligonucleotide or small interfering RNA (siRNA) that target PNPLA3 and HSD17B13 are already being evaluated in phase 1-2 clinical trials for MASH currently.90 Early reports do suggest some encouraging results; recently, early phase data pertaining to JNJ-75220795 (also known as ARO-PNPLA3), a hepatocyte-targeted N-acetylgalactosamine–conjugated siRNA against PNPLA3, demonstrated reduction of liver fat content in homozygous subjects for the PNPLA3 I148M variant.91 The full results from these trials will help to further inform and guide emerging therapeutic strategic approaches in precision medicine. More tools are urgently needed to enable precision medicine as well as personalized medicine to be translated into clinical practice.

MASLD is the most common chronic liver disease at present, with increasing prevalence and clinical burden worldwide. The clinical phenotype is affected by a multitude of factors, of which genetic factors play a substantial role. While significant progress has been made in understanding the genomics of MASLD, more needs to be clarified.

Awareness of these factors, how they are related to the underlying pathogenesis and determining their functional impact is crucial to help identify high-risk patients and pave the way to develop novel precision medicine-orientated interventions.

Study concept and design: all authors. Data acquisition: all authors. Data analysis and interpretation: all authors. Drafting of the manuscript: all authors. Critical revision of the manuscript for important intellectual content: all authors. Approval of final manuscript: all authors.

  1. El-Kassas M, Cabezas J, Coz PI, Zheng MH, Arab JP, Awad A. Nonalcoholic fatty liver disease: current global burden. Semin Liver Dis 2022;42:401-412.
    Pubmed CrossRef
  2. Younossi ZM, Golabi P, Paik JM, Henry A, Van Dongen C, Henry L. The global epidemiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH): a systematic review. Hepatology 2023;77:1335-1347.
    Pubmed KoreaMed CrossRef
  3. Goh GB, McCullough AJ. Natural history of nonalcoholic fatty liver disease. Dig Dis Sci 2016;61:1226-1233.
    Pubmed KoreaMed CrossRef
  4. Estes C, Anstee QM, Arias-Loste MT, et al. Modeling NAFLD disease burden in China, France, Germany, Italy, Japan, Spain, United Kingdom, and United States for the period 2016-2030. J Hepatol 2018;69:896-904.
    Pubmed CrossRef
  5. Estes C, Razavi H, Loomba R, Younossi Z, Sanyal AJ. Modeling the epidemic of nonalcoholic fatty liver disease demonstrates an exponential increase in burden of disease. Hepatology 2018;67:123-133.
    Pubmed KoreaMed CrossRef
  6. Younossi ZM, Blissett D, Blissett R, et al. The economic and clinical burden of nonalcoholic fatty liver disease in the United States and Europe. Hepatology 2016;64:1577-1586.
    Pubmed CrossRef
  7. Schattenberg JM, Lazarus JV, Newsome PN, et al. Disease burden and economic impact of diagnosed non-alcoholic steatohepatitis in five European countries in 2018: a cost-of-illness analysis. Liver Int 2021;41:1227-1242.
    Pubmed KoreaMed CrossRef
  8. Goh GB, Kwan C, Lim SY, et al. Perceptions of non-alcoholic fatty liver disease: an Asian community-based study. Gastroenterol Rep (Oxf) 2016;4:131-135.
    Pubmed KoreaMed CrossRef
  9. Powell EE, Wong VW, Rinella M. Non-alcoholic fatty liver disease. Lancet 2021;397:2212-2224.
    Pubmed CrossRef
  10. Dongiovanni P, Anstee QM, Valenti L. Genetic predisposition in NAFLD and NASH: impact on severity of liver disease and response to treatment. Curr Pharm Des 2013;19:5219-5238.
    Pubmed KoreaMed CrossRef
  11. Caussy C, Soni M, Cui J, et al. Nonalcoholic fatty liver disease with cirrhosis increases familial risk for advanced fibrosis. J Clin Invest 2017;127:2697-2704.
    Pubmed KoreaMed CrossRef
  12. Loomba R, Schork N, Chen CH, et al. Heritability of hepatic fibrosis and steatosis based on a prospective twin study. Gastroenterology 2015;149:1784-1793.
    Pubmed KoreaMed CrossRef
  13. Guerrero R, Vega GL, Grundy SM, Browning JD. Ethnic differences in hepatic steatosis: an insulin resistance paradox?. Hepatology 2009;49:791-801.
    Pubmed KoreaMed CrossRef
  14. Ebrahimi F, Hagström H, Sun J, et al. Familial coaggregation of MASLD with hepatocellular carcinoma and adverse liver outcomes: nationwide multigenerational cohort study. J Hepatol 2023;79:1374-1384.
    Pubmed CrossRef
  15. Chen Y, Du X, Kuppa A, et al. Genome-wide association meta-analysis identifies 17 loci associated with nonalcoholic fatty liver disease. Nat Genet 2023;55:1640-1650.
    Pubmed KoreaMed CrossRef
  16. Xiao L, Li Y, Hong C, et al. Polygenic risk score of metabolic dysfunction-associated steatotic liver disease amplifies the health impact on severe liver disease and metabolism-related outcomes. J Transl Med 2024;22:650.
    Pubmed KoreaMed CrossRef
  17. Romeo S, Kozlitina J, Xing C, et al. Genetic variation in PNPLA3 confers susceptibility to nonalcoholic fatty liver disease. Nat Genet 2008;40:1461-1465.
    Pubmed KoreaMed CrossRef
  18. Speliotes EK, Butler JL, Palmer CD, et al. PNPLA3 variants specifically confer increased risk for histologic nonalcoholic fatty liver disease but not metabolic disease. Hepatology 2010;52:904-912.
    Pubmed KoreaMed CrossRef
  19. Rotman Y, Koh C, Zmuda JM, Kleiner DE, Liang TJ; NASH CRN. The association of genetic variability in patatin-like phospholipase domain-containing protein 3 (PNPLA3) with histological severity of nonalcoholic fatty liver disease. Hepatology 2010;52:894-903.
    Pubmed KoreaMed CrossRef
  20. Valenti L, Al-Serri A, Daly AK, et al. Homozygosity for the patatin-like phospholipase-3/adiponutrin I148M polymorphism influences liver fibrosis in patients with nonalcoholic fatty liver disease. Hepatology 2010;51:1209-1217.
    Pubmed CrossRef
  21. Pennisi G, Pipitone RM, Cammà C, et al. PNPLA3 rs738409 C>G variant predicts fibrosis progression by noninvasive tools in nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol 2021;19:1979-1981.
    Pubmed CrossRef
  22. Singal AG, Manjunath H, Yopp AC, et al. The effect of PNPLA3 on fibrosis progression and development of hepatocellular carcinoma: a meta-analysis. Am J Gastroenterol 2014;109:325-334.
    Pubmed KoreaMed CrossRef
  23. Liu YL, Patman GL, Leathart JB, et al. Carriage of the PNPLA3 rs738409 C >G polymorphism confers an increased risk of non-alcoholic fatty liver disease associated hepatocellular carcinoma. J Hepatol 2014;61:75-81.
    Pubmed CrossRef
  24. Grimaudo S, Pipitone RM, Pennisi G, et al. Association between PNPLA3 rs738409 C>G variant and liver-related outcomes in patients with nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol 2020;18:935-944.
    Pubmed CrossRef
  25. Carlsson B, Lindén D, Brolén G, et al. Review article: the emerging role of genetics in precision medicine for patients with non-alcoholic steatohepatitis. Aliment Pharmacol Ther 2020;51:1305-1320.
    Pubmed KoreaMed CrossRef
  26. Kozlitina J, Smagris E, Stender S, et al. Exome-wide association study identifies a TM6SF2 variant that confers susceptibility to nonalcoholic fatty liver disease. Nat Genet 2014;46:352-356.
    Pubmed KoreaMed CrossRef
  27. Luo F, Oldoni F, Das A. TM6SF2: a novel genetic player in nonalcoholic fatty liver and cardiovascular disease. Hepatol Commun 2022;6:448-460.
    Pubmed KoreaMed CrossRef
  28. Liu YL, Reeves HL, Burt AD, et al. TM6SF2 rs58542926 influences hepatic fibrosis progression in patients with non-alcoholic fatty liver disease. Nat Commun 2014;5:4309.
    Pubmed KoreaMed CrossRef
  29. Chen X, Zhou P, De L, Li B, Su S. The roles of transmembrane 6 superfamily member 2 rs58542926 polymorphism in chronic liver disease: a meta-analysis of 24,147 subjects. Mol Genet Genomic Med 2019;7:e824.
    Pubmed KoreaMed CrossRef
  30. Luukkonen PK, Zhou Y, Hyötyläinen T, et al. The MBOAT7 variant rs641738 alters hepatic phosphatidylinositols and increases severity of non-alcoholic fatty liver disease in humans. J Hepatol 2016;65:1263-1265.
    Pubmed CrossRef
  31. Mancina RM, Dongiovanni P, Petta S, et al. The MBOAT7-TMC4 variant rs641738 increases risk of nonalcoholic fatty liver disease in individuals of European descent. Gastroenterology 2016;150:1219-1230.
    Pubmed KoreaMed CrossRef
  32. Donati B, Dongiovanni P, Romeo S, et al. MBOAT7 rs641738 variant and hepatocellular carcinoma in non-cirrhotic individuals. Sci Rep 2017;7:4492.
    Pubmed KoreaMed CrossRef
  33. Teo K, Abeysekera KW, Adams L, et al. rs641738C>T near MBOAT7 is associated with liver fat, ALT and fibrosis in NAFLD: a meta-analysis. J Hepatol 2021;74:20-30.
    Pubmed KoreaMed CrossRef
  34. Hernaez R, McLean J, Lazo M, et al. Association between variants in or near PNPLA3, GCKR, and PPP1R3B with ultrasound-defined steatosis based on data from the third National Health and Nutrition Examination Survey. Clin Gastroenterol Hepatol 2013;11:1183-1190.
    Pubmed KoreaMed CrossRef
  35. Santoro N, Zhang CK, Zhao H, et al. Variant in the glucokinase regulatory protein (GCKR) gene is associated with fatty liver in obese children and adolescents. Hepatology 2012;55:781-789.
    Pubmed KoreaMed CrossRef
  36. Kawaguchi T, Shima T, Mizuno M, et al. Risk estimation model for nonalcoholic fatty liver disease in the Japanese using multiple genetic markers. PLoS One 2018;13:e0185490.
    Pubmed KoreaMed CrossRef
  37. Tan HL, Zain SM, Mohamed R, et al. Association of glucokinase regulatory gene polymorphisms with risk and severity of non-alcoholic fatty liver disease: an interaction study with adiponutrin gene. J Gastroenterol 2014;49:1056-1064.
    Pubmed CrossRef
  38. Abul-Husn NS, Cheng X, Li AH, et al. A protein-truncating HSD17B13 variant and protection from chronic liver disease. N Engl J Med 2018;378:1096-1106.
    Pubmed KoreaMed CrossRef
  39. Pirola CJ, Garaycoechea M, Flichman D, et al. Splice variant rs72613567 prevents worst histologic outcomes in patients with nonalcoholic fatty liver disease. J Lipid Res 2019;60:176-185.
    Pubmed KoreaMed CrossRef
  40. Yang J, Trépo E, Nahon P, et al. A 17-beta-hydroxysteroid dehydrogenase 13 variant protects from hepatocellular carcinoma development in alcoholic liver disease. Hepatology 2019;70:231-240.
    Pubmed CrossRef
  41. Gellert-Kristensen H, Nordestgaard BG, Tybjaerg-Hansen A, Stender S. High risk of fatty liver disease amplifies the alanine transaminase-lowering effect of a HSD17B13 variant. Hepatology 2020;71:56-66.
    Pubmed CrossRef
  42. Jonas W, Schürmann A. Genetic and epigenetic factors determining NAFLD risk. Mol Metab 2021;50:101111.
    Pubmed KoreaMed CrossRef
  43. Pingitore P, Romeo S. The role of PNPLA3 in health and disease. Biochim Biophys Acta Mol Cell Biol Lipids 2019;1864:900-906.
    Pubmed CrossRef
  44. Sliz E, Sebert S, Würtz P, et al. NAFLD risk alleles in PNPLA3, TM6SF2, GCKR and LYPLAL1 show divergent metabolic effects. Hum Mol Genet 2018;27:2214-2223.
    Pubmed KoreaMed CrossRef
  45. Luukkonen PK, Nick A, Hölttä-Vuori M, et al. Human PNPLA3-I148M variant increases hepatic retention of polyunsaturated fatty acids. JCI Insight 2019;4:e127902.
    Pubmed KoreaMed CrossRef
  46. Wang Y, Kory N, BasuRay S, Cohen JC, Hobbs HH. PNPLA3, CGI-58, and inhibition of hepatic triglyceride hydrolysis in mice. Hepatology 2019;69:2427-2441.
    Pubmed KoreaMed CrossRef
  47. Mitsche MA, Hobbs HH, Cohen JC. Patatin-like phospholipase domain-containing protein 3 promotes transfer of essential fatty acids from triglycerides to phospholipids in hepatic lipid droplets. J Biol Chem 2018;293:6958-6968.
    Pubmed KoreaMed CrossRef
  48. BasuRay S, Smagris E, Cohen JC, Hobbs HH. The PNPLA3 variant associated with fatty liver disease (I148M) accumulates on lipid droplets by evading ubiquitylation. Hepatology 2017;66:1111-1124.
    Pubmed KoreaMed CrossRef
  49. Johnson SM, Bao H, McMahon CE, et al. PNPLA3 is a triglyceride lipase that mobilizes polyunsaturated fatty acids to facilitate hepatic secretion of large-sized very low-density lipoprotein. Nat Commun 2024;15:4847.
    Pubmed KoreaMed CrossRef
  50. Yang A, Mottillo EP, Mladenovic-Lucas L, Zhou L, Granneman JG. Dynamic interactions of ABHD5 with PNPLA3 regulate triacylglycerol metabolism in brown adipocytes. Nat Metab 2019;1:560-569.
    Pubmed KoreaMed CrossRef
  51. Mondul A, Mancina RM, Merlo A, et al. PNPLA3 I148M variant influences circulating retinol in adults with nonalcoholic fatty liver disease or obesity. J Nutr 2015;145:1687-1691.
    Pubmed KoreaMed CrossRef
  52. Salameh H, Hanayneh MA, Masadeh M, et al. PNPLA3 as a genetic determinant of risk for and severity of non-alcoholic fatty liver disease spectrum. J Clin Transl Hepatol 2016;4:175-191.
    CrossRef
  53. Sookoian S, Pirola CJ. Meta-analysis of the influence of I148M variant of patatin-like phospholipase domain containing 3 gene (PNPLA3) on the susceptibility and histological severity of nonalcoholic fatty liver disease. Hepatology 2011;53:1883-1894.
    Pubmed CrossRef
  54. Unalp-Arida A, Ruhl CE. Patatin-like phospholipase domain-containing protein 3 I148M and liver fat and fibrosis scores predict liver disease mortality in the U.S. population. Hepatology 2020;71:820-834.
    Pubmed CrossRef
  55. Meffert PJ, Repp KD, Völzke H, et al. The PNPLA3 SNP rs738409:G allele is associated with increased liver disease-associated mortality but reduced overall mortality in a population-based cohort. J Hepatol 2018;68:858-860.
    Pubmed CrossRef
  56. Kantartzis K, Peter A, Machicao F, et al. Dissociation between fatty liver and insulin resistance in humans carrying a variant of the patatin-like phospholipase 3 gene. Diabetes 2009;58:2616-2623.
    Pubmed KoreaMed CrossRef
  57. Anstee QM, Day CP. The genetics of nonalcoholic fatty liver disease: spotlight on PNPLA3 and TM6SF2. Semin Liver Dis 2015;35:270-290.
    Pubmed CrossRef
  58. Huang Y, He S, Li JZ, et al. A feed-forward loop amplifies nutritional regulation of PNPLA3. Proc Natl Acad Sci U S A 2010;107:7892-7897.
    Pubmed KoreaMed CrossRef
  59. Stender S, Kozlitina J, Nordestgaard BG, Tybjærg-Hansen A, Hobbs HH, Cohen JC. Adiposity amplifies the genetic risk of fatty liver disease conferred by multiple loci. Nat Genet 2017;49:842-847.
    Pubmed KoreaMed CrossRef
  60. Romeo S, Sentinelli F, Dash S, et al. Morbid obesity exposes the association between PNPLA3 I148M (rs738409) and indices of hepatic injury in individuals of European descent. Int J Obes (Lond) 2010;34:190-194.
    Pubmed CrossRef
  61. Palmer CN, Maglio C, Pirazzi C, et al. Paradoxical lower serum triglyceride levels and higher type 2 diabetes mellitus susceptibility in obese individuals with the PNPLA3 148M variant. PLoS One 2012;7:e39362.
    Pubmed KoreaMed CrossRef
  62. Lin H, Wong GL, Whatling C, et al. Association of genetic variations with NAFLD in lean individuals. Liver Int 2022;42:149-160.
    Pubmed CrossRef
  63. Dongiovanni P, Petta S, Maglio C, et al. Transmembrane 6 superfamily member 2 gene variant disentangles nonalcoholic steatohepatitis from cardiovascular disease. Hepatology 2015;61:506-514.
    Pubmed CrossRef
  64. Palmer ND, Musani SK, Yerges-Armstrong LM, et al. Characterization of European ancestry nonalcoholic fatty liver disease-associated variants in individuals of African and Hispanic descent. Hepatology 2013;58:966-975.
    Pubmed KoreaMed CrossRef
  65. Pirola CJ, Sookoian S. The dual and opposite role of the TM6SF2-rs58542926 variant in protecting against cardiovascular disease and conferring risk for nonalcoholic fatty liver: a meta-analysis. Hepatology 2015;62:1742-1756.
    Pubmed CrossRef
  66. Li XY, Liu Z, Li L, Wang HJ, Wang H. TM6SF2 rs58542926 is related to hepatic steatosis, fibrosis and serum lipids both in adults and children: a meta-analysis. Front Endocrinol (Lausanne) 2022;13:1026901.
    Pubmed KoreaMed CrossRef
  67. Fuchsberger C, Flannick J, Teslovich TM, et al. The genetic architecture of type 2 diabetes. Nature 2016;536:41-47.
    Pubmed KoreaMed CrossRef
  68. Matsuda S, Inoue T, Lee HC, et al. Member of the membrane-bound O-acyltransferase (MBOAT) family encodes a lysophospholipid acyltransferase with broad substrate specificity. Genes Cells 2008;13:879-888.
    Pubmed CrossRef
  69. Meroni M, Longo M, Fracanzani AL, Dongiovanni P. MBOAT7 down-regulation by genetic and environmental factors predisposes to MAFLD. EBioMedicine 2020;57:102866.
    Pubmed KoreaMed CrossRef
  70. Caddeo A, Spagnuolo R, Maurotti S. MBOAT7 in liver and extrahepatic diseases. Liver Int 2023;43:2351-2364.
    Pubmed CrossRef
  71. Eslam M, Valenti L, Romeo S. Genetics and epigenetics of NAFLD and NASH: clinical impact. J Hepatol 2018;68:268-279.
    Pubmed CrossRef
  72. Raimondo A, Rees MG, Gloyn AL. Glucokinase regulatory protein: complexity at the crossroads of triglyceride and glucose metabolism. Curr Opin Lipidol 2015;26:88-95.
    Pubmed KoreaMed CrossRef
  73. Beer NL, Tribble ND, McCulloch LJ, et al. The P446L variant in GCKR associated with fasting plasma glucose and triglyceride levels exerts its effect through increased glucokinase activity in liver. Hum Mol Genet 2009;18:4081-4088.
    Pubmed KoreaMed CrossRef
  74. Su W, Mao Z, Liu Y, et al. Role of HSD17B13 in the liver physiology and pathophysiology. Mol Cell Endocrinol 2019;489:119-125.
    Pubmed CrossRef
  75. Ma Y, Belyaeva OV, Brown PM, et al. 17-Beta hydroxysteroid dehydrogenase 13 is a hepatic retinol dehydrogenase associated with histological features of nonalcoholic fatty liver disease. Hepatology 2019;69:1504-1519.
    Pubmed KoreaMed CrossRef
  76. Seko Y, Yamaguchi K, Tochiki N, et al. Attenuated effect of PNPLA3 on hepatic fibrosis by HSD17B13 in Japanese patients with non-alcoholic fatty liver disease. Liver Int 2020;40:1686-1692.
    Pubmed CrossRef
  77. Vilar-Gomez E, Pirola CJ, Sookoian S, Wilson LA, Liang T, Chalasani N. The protection conferred by HSD17B13 rs72613567 polymorphism on risk of steatohepatitis and fibrosis may be limited to selected subgroups of patients with NAFLD. Clin Transl Gastroenterol 2021;12:e00400.
    Pubmed KoreaMed CrossRef
  78. Bianco C, Jamialahmadi O, Pelusi S, et al. Non-invasive stratification of hepatocellular carcinoma risk in non-alcoholic fatty liver using polygenic risk scores. J Hepatol 2021;74:775-782.
    Pubmed KoreaMed CrossRef
  79. Thomas CE, Diergaarde B, Kuipers AL, et al. NAFLD polygenic risk score and risk of hepatocellular carcinoma in an East Asian population. Hepatol Commun 2022;6:2310-2321.
    Pubmed KoreaMed CrossRef
  80. Chen VL, Oliveri A, Miller MJ, et al. PNPLA3 genotype and diabetes identify patients with nonalcoholic fatty liver disease at high risk of incident cirrhosis. Gastroenterology 2023;164:966-977.
    Pubmed KoreaMed CrossRef
  81. Pennisi G, Pipitone RM, Enea M, et al. A Genetic and Metabolic Staging system for predicting the outcome of nonalcoholic fatty liver disease. Hepatol Commun 2022;6:1032-1044.
    Pubmed KoreaMed CrossRef
  82. Gellert-Kristensen H, Richardson TG, Davey Smith G, Nordestgaard BG, Tybjaerg-Hansen A, Stender S. Combined effect of PNPLA3, TM6SF2, and HSD17B13 variants on risk of cirrhosis and hepatocellular carcinoma in the general population. Hepatology 2020;72:845-856.
    Pubmed CrossRef
  83. De Vincentis A, Tavaglione F, Jamialahmadi O, et al. A polygenic risk score to refine risk stratification and prediction for severe liver disease by clinical fibrosis scores. Clin Gastroenterol Hepatol 2022;20:658-673.
    Pubmed CrossRef
  84. Shen J, Wong GL, Chan HL, et al. PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease. J Gastroenterol Hepatol 2015;30:139-146.
    Pubmed CrossRef
  85. Seko Y, Yamaguchi K, Tochiki N, et al. The effect of genetic polymorphism in response to body weight reduction in Japanese patients with nonalcoholic fatty liver disease. Genes (Basel) 2021;12:628.
    Pubmed KoreaMed CrossRef
  86. Aller R, Laserna C, Rojo MÁ, et al. Role of the PNPLA3 polymorphism rs738409 on silymarin + vitamin E response in subjects with non-alcoholic fatty liver disease. Rev Esp Enferm Dig 2018;110:634-640.
    Pubmed CrossRef
  87. Chen Y, Yan X, Xu X, Yuan S, Xu F, Liang H. PNPLA3 I148M is involved in the variability in anti-NAFLD response to exenatide. Endocrine 2020;70:517-525.
    Pubmed CrossRef
  88. Nelson MR, Tipney H, Painter JL, et al. The support of human genetic evidence for approved drug indications. Nat Genet 2015;47:856-860.
    Pubmed CrossRef
  89. Sabatine MS, Giugliano RP, Keech AC, et al. Evolocumab and clinical outcomes in patients with cardiovascular disease. N Engl J Med 2017;376:1713-1722.
    Pubmed CrossRef
  90. Lindén D, Romeo S. Therapeutic opportunities for the treatment of NASH with genetically validated targets. J Hepatol 2023;79:1056-1064.
    Pubmed CrossRef
  91. Fabbrini E, Rady B, Koshkina A, et al. Phase 1 trials of PNPLA3 siRNA in I148M homozygous patients with MAFLD. N Engl J Med 2024;391:475-476.
    Pubmed CrossRef

Article

Review Article

Gut and Liver 2025; 19(1): 8-18

Published online January 15, 2025 https://doi.org/10.5009/gnl240407

Copyright © Gut and Liver.

Genetic Risk Factors for Metabolic Dysfunction-Associated Steatotic Liver Disease

Yiying Pei1,2 , George Boon-Bee Goh1,2

1Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore; 2Medicine Academic Clinical Program, Duke-National University of Singapore (Duke-NUS) Medical School, Singapore

Correspondence to:George Boon-Bee Goh
ORCID https://orcid.org/0000-0001-8221-5299
E-mail goh.boon.bee@singhealth.com.sg

Received: September 23, 2024; Revised: November 4, 2024; Accepted: November 7, 2024

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Metabolic dysfunction-associated steatotic liver disease (MASLD), is the most common cause of liver disease, and its burden on health systems worldwide continues to rise at an alarming rate. MASLD is a complex disease in which the interactions between susceptible genes and the environment influence the disease phenotype and severity. Advances in human genetics over the past few decades have provided new opportunities to improve our understanding of the multiple pathways involved in the pathogenesis of MASLD. Notably, the PNPLA3, TM6SF2, GCKR, MBOAT7 and HSD17B13 single nucleotide polymorphisms have been demonstrated to be robustly associated with MASLD development and disease progression. These genetic variants play crucial roles in lipid droplet remodeling, secretion of hepatic very low-density lipoprotein and lipogenesis, and understanding the biology has brought new insights to this field. This review discusses the current body of knowledge regarding these genetic drivers and how they can lead to development of MASLD, the complex interplay with metabolic factors such as obesity, and how this information has translated clinically into the development of risk prediction models and possible treatment targets.

Keywords: Metabolic dysfunction-associated steatotic liver disease, Genetic, PNPLA3, Risk stratification, Treatment

INTRODUCTION

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is now the most common chronic liver disease globally,1 with an ever growing prevalence, increasing from 25.3% in 1990–2006 to 38% in subsequent period of 2016–2019.2 Defined by the presence of hepatic steatosis in conjunction with metabolic dysfunction, MASLD includes a wide spectrum of clinical phenotypes, from simple steatosis, steatohepatitis, to fibrosis and ultimately cirrhosis. Recognizing the high prevalence and natural history profile of MASLD, the anticipated disease burden in years to come is of great concern.3 Modelling studies project increasing incidences of hepatocellular carcinoma (HCC), decompensated cirrhosis and MASLD-related mortality by 2030.4 All this contributes to the bourgeoning socio-economic health burden worldwide from both the clinical and public health perspectives.5-7

As MASLD is usually clinically asymptomatic and insidious, awareness and insight regarding perceived risk may not seem so evident.8 As such, it remains critical for continued efforts to highlight MASLD amongst all stakeholders, including associated risk factors.

The bi-directional relationship between MASLD and metabolic factors has been well established. With advances in human genetics over the past few decades, our understanding of the multiple pathways, interactions and contributions between the various factors involved in the pathogenesis of MASLD continue to evolve and provide new opportunities in innovative research.9 Here, we will be focusing on genetic risk factors, which represent significant factors at play in MASLD. Besides potentially identifying at risk individuals at a deeper level, genetic profiling may also allow development of novel biomarkers and targeting of specific gene pathways in a personalized precision medicine approach.

IMPORTANCE OF GENETIC RISK FACTORS

Genetic and epidemiological studies have indicated strong heritability of hepatic fat.10 This evidence comes from familial aggregation studies that demonstrated that first-degree relatives have up to 12-fold increased risk of MASLD compared to the general population.11 Another study performed in 2009 revealed that MASLD was more common in siblings (59%) and parents (78%) of children with MASLD, despite adjustments for age, sex, race, and body mass index (BMI). Separately, twin studies suggest between 35% and 61% hereditability for MASLD.12 Multi-ethnic cohorts also highlight major inter-ethnic variability in MASLD susceptibility, proving that the risks are higher in Hispanics, intermediate in Europeans and lower in individuals of African descent, independent of confounders.13

The risk is not limited to the diagnosis of MASLD but also to poorer liver-related outcomes. A recent nationwide multigenerational cohort study performed in 38,000 Swedish adults who are first-degree relatives of patients with biopsy proven MASLD found that the rate of HCC, major adverse liver outcomes, and liver-related mortality was 1.8 times, 1.52 times, and 2.14 times higher respectively than comparator first-degree relatives, illustrating a distinct familial clustering.14

Genome-wide association studies (GWAS) cemented the awareness and importance of genetic factors in the pathogenesis of MASLD, and opened up exciting new opportunities to address the unmet need for therapeutics in MASLD. In the age of precision medicine, the identification of patients with specific gene variants may allow individual and targeted treatment via specific genetic pathways.

While there are many genetic factors reported in the literature to be associated with NAFLD,15 and more recently MASLD,16 the most well studied and strongest association has been suggested in the following five single nucleotide polymorphisms (SNPs) as summarized in Table 1. These five genes known to be associated with MASLD are all involved in glucose and fat homeostasis regulatory pathways as illustrated in Fig. 1.

Figure 1. Genetic loci involved in the susceptibility and pathophysiology of fatty liver disease. PNPLA3, patatin-like phospholipase domain-containing protein 3; HSD17B13, hydroxysteroid 17-beta dehydrogenase 13; VLDL, very low-density lipoprotein; APOB, apolipoprotein B; MBOAT7, membrane bound O-acyltransferase domain-containing 7; GCKR, glucokinase regulator; TM6SF2, transmembrane 6 superfamily member 2; MASLD, metabolic dysfunction-associated steatotic liver disease.

Table 1 . Genetic Variants Associated with MASLD.

GeneGenetic variantAffected proteinEffectPathophysiologyEffect on hepatic steatosisEffect on NASHEffect on fibrosis/cirrhosisEffect on HCCMortalityReference
PNPLA3rs738409 C>GI148M

Complex.

Gain of function and also loss of function.

Lipid droplet remodeling18-24
TM6SF2rs58542926 G>AE167KLoss of functionInhibits secretion of VLDL in hepatocytes-25-29
MBOAT7rs641738 C>TLysophosphatidylinositol-acyltransferase 1 (LPIAT1)DownregulationPhospholipid remodeling-30-33
GCRK

rs780094 C>T.

rs1260326 C>T.

Intronic variant.

P446L.

Loss of functionIncreases de novo lipogenesis--34-37
HSD17B13*rs72613567 T>TASplice donor variantLoss of functionLipid droplet remodeling-38-41

MASLD, metabolic dysfunction-associated steatotic liver disease; NASH, nonalcoholic steatohepatitis; HCC, hepatocellular carcinoma; VLDL, very low-density lipoprotein..

*There are many variants within the HSD17B13 gene, including rs6834314 A>G, rs62305723 G>A, rs10433937 T>A, T>C, T>G, rs10433879 G>C, rs61748262 C>A, C>T..



1. Patatin-like phospholipase domain-containing protein 3

With the first reported landmark GWAS study in context of MASLD by Romeo et al. in 2008,17 patatin-like phospholipase domain-containing protein 3 (PNPLA3) variant was found to be associated with increased hepatic lipid content. The variant is a cytosine to guanine substitution that results in an isoleucine to methionine substitution at position 148 in PNPLA3 gene (rs738409). Subsequent studies have confirmed that this is the most robust, well-replicated genetic variant associated with MASLD.42 Furthermore, inter-ethnic variability in MASLD is likely accounted for by PNPLA3. Illustrating this, the PNPLA3 allele (rs738409[G], encoding I148M), which was strongly associated with increased hepatic fat levels was found most commonly in Hispanics, who in turn, epidemiologically have the highest susceptibility to MASLD.17

PNPLA3 codes for a triacylglycerol lipase that mobilizes polyunsaturated fatty acids from triglycerides. This facilitates the liver’s ability to secrete large-sized very low-density lipoprotein (VLDL), which transports triglycerides from the liver to other tissues.43,44 The current understanding is that the genetic variant is possibly inducing both a gain- as well as a loss of function effect. A loss of function of this allele can hinder the formation and secretion of VLDL,45 further contributing to triglyceride accumulation in the liver because the liver is less able to export the excess fat.46,47

The I148M mutant of PNPLA3 tends to accumulate on the surface of lipid droplets.48 Recent studies have shown that this protein mutant suppresses adipose triglyceride lipase-mediated lipolysis,49 by competing for the co-activator comparative gene identification-58 at the surface of the lipid droplets.46 This gain of function mutation involving transrepression of adipose triglyceride lipase results in impaired lipid turnover and results in accumulation in hepatocytes.50 Impairment of retinol release from the lipid droplets of hepatic stellate cells resulting in an inflammatory response and fibrogenesis in carriers of the PNPL3 I148M has also been suggested as a contributory mechanism.51

Clinically, it is associated with rise in hepatic fat content,18,52 elevated liver enzymes, fibrosis,19-21,53 cirrhosis and HCC,22,23 carrying an odds ratio of 1.91 for MASLD, 2.54 for metabolic dysfunction-associated steatohepatitis (MASH), and 2.68 to 5 for HCC.24,25 In keeping with these findings, PNPLA3 was also found to be associated with the risk of hepatic decompensation (hazard ratio, 2.1), liver-related mortality (hazard ratio, 3.64)24 as well as overall mortality.54

Interestingly, this effect is independent of alterations in glucose homeostasis or lipoprotein metabolism.17,24 There is also no association of this variant with BMI, triglyceride levels, high and low-density lipoprotein levels, or diabetes.17,55 This may be related to the dissociation between the PNPLA3 genetic variant with insulin resistance, estimated from oral glucose tolerance test and measured by the euglycemic-hyper insulinemic clamp.56 This has led to the postulation that the effect of PNPLA3 variant on the degree of hepatic steatosis is not related to insulin sensitivity or resistance, but rather that it sets off a multi-step process that is more subtle, sensitizing the liver to metabolic stress due to nutritional calorific excess.57 In mouse models, PNPLA3 expression is upregulated by carbohydrate feeding through the liver X receptor/sterol regulatory element binding protein-1c pathway.58 Thus, loss of function of this gene under lipogenic conditions provides a potential explanation for the increased susceptibility of patients carrying the I148M variant to the development of liver steatosis and MASLD.49 This can also be seen in how morbid obesity acting as a stressor on a specific genetic background may influence susceptibility to MASLD.57,59 An Italian genetic association analysis found that morbidly obese patients carrying the PNPLA3 148M allele have increased levels of alanine transaminase and aspartate transaminase without any differences in insulin sensitivity or glucose tolerance.60 This shows that patients with obesity will have a more extreme liver injury with the PNPLA3 148M allele than lean individuals.61 Among lean persons (BMI <25 kg/m2), hepatic steatosis in the MM homozygous individuals was at 2.8% versus 1.8% in the II homozygous individuals, whereas in those who were obese (BMI >35 kg/m2), hepatic fat was 14.2% versus 4.7% in MM than in II individuals, demonstrating that the effect of the M variant increased with increasing BMI.59 This finding was also replicated in an Asian (Hong Kong) population which found that the median intrahepatic triglyceride increased only mildly in the lean group (1.5% in wild type vs 2.8% in homozygotes), but tripled in the obese subgroup (4.7% in wild type vs 14.2% in homozygotes).62

2. Transmembrane 6 superfamily member 2

Transmembrane 6 superfamily member 2 (TM6SF2) regulates the hepatic VLDL secretion pathway.26 The G to A substitution encoding glutamate to lysine substitution at position 167 at the rs58542926 SNP results in loss of function in the hepatic VLDL secretion pathway, inducing higher liver triglyceride content, resulting in increased susceptibility to liver damage.27

This impairment in cholesterol metabolism leads to increased liver fat content, MASH, advanced fibrosis and cirrhosis,28,63 and even HCC in mouse models,27 with allelic odds ratio of 1.82 for MASLD and 1.37 for MASH.25,29 This genetic variation associated with advanced hepatic fibrosis is independent of potential confounding factors such as age, BMI, type 2 diabetes mellitus (T2DM) and PNPLA3 rs738409 genotype.28,63 While this genetic variant has a moderate to large effect size, it is a generally low frequency variant, and shows inter-ethnic variations in its carriage.64

Of note, it is associated with a lower cardiovascular risk, postulated to be due to diminished circulating levels of cholesterol and lipids65 because these instead accumulate in the liver.62,63 It has been suggested that TM6SF2 controls hepatic lipid efflux, as loss of function of the gene results in a reduction in lipoprotein secretion (VLDL, triglyceride [TG], and apolipoprotein B), which leads to increased hepatocellular lipid droplet size and TG accumulation in the liver.66 This variant has also been related to the development of T2DM.67

3. Membrane-bound O-acyltransferase domain-containing 7

Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7) encodes lysophosphatidylinositol-acyltransferase 1, which is involved in incorporating arachidonic acid and other unsaturated fatty acids into lysophospholipids, producing a component of cell membranes called phosphatidylinositol.68 The rs641738 SNP variant linked to 3’UTR of MBOAT7 is associated with the downregulation of MBOAT7, which reduces levels of phosphatidylinositol-containing arachidonic acid and increases levels of saturated lysophosphatidylinositol.30 This is a proinflammatory molecule involved in macrophage and endothelial cell activation and induces de novo lipogenesis and inhibits beta oxidation in hepatocytes. The downregulation of this gene also favors the accumulation of free arachidonic acid, a known driver of hepatic inflammation.31,69,70

This variant is linked with an increased risk of MASLD, inflammation, fibrosis, and HCC.31,32 It carries allelic an odds ratio of 1.15 (95% confidence interval [CI], 1.05 to 1.26) for MASLD, 1.24 (95% CI, 0.81 to 1.90) for MASH, 1.2 (95% CI, 1.02 to 1.42) for advanced fibrosis and 1.4 (95% CI, 0.99 to 1.98) for HCC.33 However, the effect size is small compared to PNPLA4 and TM6SF2. No effect on fasting insulin levels was found in population-level GWAS (β=0.009 [95% CI, –0.03 to 0.04], pz=0.6461), indicating lack of an effect of rs641738C>T on insulin resistance.33

4. Glucokinase regulator

Glucokinase regulator (GCKR) is an inhibitor of glucokinase (GCK), and its hepatic concentration is increased in MASLD. The GCKR gene is involved in the glucose control and metabolism in hepatocytes.71 The rs780094 C>T gene variant has been shown to be related to hepatic steatosis not just in adults,34 but another loss of function variant rs1260326 C>T SNP was even associated with increased risk of MASLD in obese children and adolescents.35 The SNP rs1260326 results in a loss of function variant that increases de novo lipogenesis by inducing glycolytic influx and glucose uptake.72 GCK, which is inhibited by the GCKR protein, catalyzes the beginning of the glycolytic pathway. With the P446L GCKR variant, this inhibition is reduced, resulting in increased activity of GCK, promoting the glycolytic pathway and elevating concentrations of a precursor for fatty acid biosynthesis, leading to the accumulation of hepatic lipids.73 This gene is associated with MASLD, MASH, and HCC with allelic odds ratio of 1.38 to 1.49 for MASLD,36,37 1.5 for MASH, and 1.52 for fibrosis.37

5. Hydroxysteroid 17-beta dehydrogenase 13

Hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) is a hepatic lipid droplet protein which is involved in steroid hormone signaling as well as lipid droplet remodeling,74 and has multiple polymorphisms including rs72613567 SNP variant, rs143404524, rs62305723. All these variants alter genetic splicing that results in truncated or stable HSD17B13 proteins that have a marked loss of enzymatic activity that protect against liver injury,38,39 including MASH, ballooning, lobular inflammation and fibrosis. The allelic odds ratios have been reported to be 0.84 for MASLD, 0.86 for MASH, and 0.67 to 0.77 for HCC,25,40 and each minor allele has been found to decrease the risk of cirrhosis and cirrhosis-associated mortality by 15% (95% CI, 0.74 to 0.98) and 49% (95% CI, 0.32 to 0.81), respectively.41 The protective role seems to be associated with retinol metabolism, via retinol dehydrogenase activity, inflammation and fibrogenesis rather than simply lipid accumulation in the liver.75

Another exciting finding was that rs72613567 interacted with PNPLA3 I148M, mitigating the effects of liver injury as well as that of advanced fibrosis.76 However, the effect may be influenced by the presence of other factors, as a recent analysis found that the protective effect of HSD17B13 rs72613567 was significant only in selected subgroups of individuals–those aged ≥45 years, women and have class ≥2 obesity or diabetes, and those with PNPLA3 rs738409 CC genotype.77

CLINICAL AND TRANSLATIONAL IMPLICATIONS

Given the high effect sizes and genotypic variability associated with MASLD, there was optimism that precision medicine would be translatable to develop new drug targets as well as biomarkers to treat and/or predict MASLD and its liver-related events. Unfortunately, to date, none of the known variants, despite being widely studied, have successfully transitioned into established clinical use. Improvement in risk stratification and development of effective therapies for fatty liver disease remain key unmet clinical needs. Nevertheless, knowledge emerging from genomics could meet this need via use of polygenic risk scores for early disease detection and stratification of severity of fatty liver disease.

1. Risk stratification

There are studies in progress studying the use of these genetic variants as part of risk prediction models.

Bianco et al.78 were able to predict HCC using a polygenic risk score in a European cohort based on PNPLA3, TM6SF2, GCKR, MBOAT7–common genetic variants associated with hepatic fat content (PRS‐HFC), and thereafter further adjusted for HSD17B13 as well, in a second score called PRS‐5. They showed that the PRS-HFC was significantly associated with increased risk of HCC, estimated to be around 3-fold, in the MASLD cohort, though diagnostic accuracy was only moderate (Table 2).78 These results have also been shown to be useful in an Asian population.79 The potential ability to predict HCC was verified with the HCC risk prediction score that was able to identify at risk patients with an area under the curve (AUROC) of 0.96.32

Table 2 . Risk Prediction Scores for Liver-Related Outcomes.

ScoreGenetic variant and components of scoreMethodCohortPredicted outcomeAUROCDiagnostic thresholdOdds ratioSensitivitySpecificityReference
Genetic risk scorePNPLA3, TM6SF2, HSD17B13Blood testGeneral (European) population

Cirrhosis.

HCC.

NACombined GRS calculated as sum of risk-increasing alleles with range: 0-6

Up to 12 for cirrhosis.

Up to 29 for HCC.

NANA82
Cirrhosis polygenic risk scorePNPLA3, TM6SF2, HSD17B13, MBOAT7, GCKR, TRIB1, APOE, GPAMBlood testNAFLD with diabetes and indeterminate FIB-4 (1.3–2.67)Cirrhosis or portal hypertensive complications0.73NANANANA80
PNPLA3-rs738409-GG genotypePNPLA30.78Presence of GG genotypeNA0.300.93
HCC risk score*Age, sex, obesity, T2DM, severe fibrosis, number of risk alleles (PNPLA3, TM6SF2 MBOAT7)Composite score with clinical, metabolic and genetic factorsNAFLDHCC0.96NA13.40.960.8932
Polygenic risk score–hepatic fat content (PRS-HFC)PNPLA3, TM6SF2, MBOAT7, GCKRBlood testNAFLDHCC0.640.5323.00.430.8078
Polygenic risk score considering 5 risk variants (PRS-5)PNPLA3, TM6SF2, MBOAT7, GCKR, HSD17B13Blood testNAFLDHCC0.650.4952.90.430.7978
Genetic and Metabolic Staging (GEMS) scoring system

PNPLA3, HSD17B13, TM6SF2, male sex,.

diabetes, low HDL.

Composite score of clinical, metabolic and genetic variablesNAFLD and FIB-4 ≥ 1.3Liver-related events0.87

Range from 0 to 10.

0=total absence of risk of LREs 10=highest risk of LREs, then sub-categorized into five classes: 0–5, 5–6, 6–7, 7–8, 8–10.

Risk of LREs increased from 4% in GEMS 0–5, to 91% in GEMS 8–10NANA81

AUROC, area under the curve; HCC, hepatocellular carcinoma; NA, not available; GRS, genetic risk score; NAFLD, nonalcoholic fatty liver disease; FIB-4, fibrosis-4 score; T2DM, type 2 diabetes mellitus; HDL, high-density lipoprotein; LRE, liver related events..

*A combined risk score considering acquired and genetic risk factors was developed to predict HCC: 1/(1+e− ((−12.588+(0.162×age)+(0.404×sex: 1 if male, −1 if female)+(0.259×obesity: 1 present, −1 absent)+(0.587×T2DM: 1 present, −1 absent)+(1.299×severe fibrosis: 1 yes, −1 no)+(0.442×number of risk alleles))); The GEMS score is calculated using the following formula: 1.163–0.438(PNPLA3 CG/GG)+0.421(male sex)–0.413(diabetes)+2.635(55≤age<65)+2.888(age>65)+0.632(low HDL)+0.668(albumin <4 g/dL)+1.935(110,000/mm33)+2.605(platelets<110,000/mm3)+0.602(HSD17B13 TTA/TATA)+0.661(TM6SF2 CT/TT)–1.146(interaction PNPLA3 CG/GG and male sex)+1.641(interaction PNPLA3 CG/GG and diabetes)..



Looking beyond HCC, risk scores incorporating genetic variables have also been able to predict incident cirrhosis in patients with NAFLD.80 The Genetic and Metabolic Staging score incorporates genetic variants with clinical and biochemical parameters to predict liver-related events within the MASLD advanced fibrosis cohort with an AUROC of 0.87 at 1, 3, and 5 years.81 However, the AUROC drops to 0.7 when applied to the general population, which marks it as suboptimal as a screening tool,81 though other studies have been promising: a genetic risk score comprising three common variants in PNPLA3, TM6SF2 and HSD17B13 has shown an association of up to 12-fold higher risk of cirrhosis and up to 29-fold higher risk of HCC.82 This shows that such genetic scores may have the potential to predict the onset and progression of chronic liver disease in the general population. Vicenti and colleagues have also looked into combining the PRS-HFC score with noninvasive fibrosis scores such as NAFLD fibrosis score and fibrosis-4 to improve prediction of cirrhosis and liver events in the overall population.83 Genetics can possibly even predict liver-related mortality, as the genetic variant PNPLA3 I148M has been found to be associated with increased liver disease mortality with a hazard ratio of 18.2.54

Overall, the current evidence suggests that genetic testing does have potential in identifying MASLD patients at higher risk of developing liver‐related events including HCC, and even of mortality, though challenges remain in the overall ability to extrapolate use of such tests in the general population.

2. Treatment

Even as the space for therapeutics for MASLD remains exciting with recent new findings, the cornerstone for MASLD treatment remains lifestyle modifications.

Data suggests that genetic variations can also affect efficacy and response to lifestyle modification and exercise in MASLD. The presence of G allele in PNPLA3 rs738409 gene polymorphism was associated with greater reduction in intrahepatic TG, body weight, waist-to-hip ratio, blood total cholesterol, and low-density lipoprotein levels in MASLD patients who were enrolled in a 12-month community-based lifestyle modification program.84 However, there was contrasting findings in a Japanese cohort that found greater reduction in body weight in MASLD patients with the c allele of PNPLA3 rs738409 rather than the G allele.85 This difference could be accounted for by the lower body weight reduction in the Japanese study, where the dietary intervention is described only as a consultation at baseline visit, as compared to a more intensive regime and personalized meal plan performed by the study by Shen et al.84 Interestingly, the impact of the G allele may be restricted beyond a minimum amount of weight loss. A closer look at the results from the Japanese study yields the finding that among patients with a body weight loss of more than 5%, the reduction of liver stiffness measurement was significantly greater according to the predominance of the G allele. The patient population amongst these two studies also may not be comparable given the higher percentage of advanced fibrosis in the Japanese study, and may suggest that the benefit of the G allele in PNPLA3 rs738409 gene polymorphism may be restricted to early intervention, prior to progression to advanced fibrosis, beyond which the impact may be lost or becomes minimal.

Genetic profiles may also be helpful in predicting response to therapy, which can guide the development of potential therapeutics. A study looking at treatment of NAFLD with silymarin – vitamin E combination was able to produce a decrease in transaminases, but PNPLA3 G-allele carriers responded poorly to the treatment.86 In patients with T2DM, treatment with exenatide improved liver fat content in patients carrying PNPLA3 148I/I better than in patients with 148M/M.87 Genetic modulation of therapeutic responses indicates that a genetic-based approach may be the way forward. Having genetically supported drug targets increases the likelihood of successful clinical development by 2-fold.88 With recent success of drug development in atherosclerosis therapy, such as the PCSK9 story, which was rooted in discovery of drug target based on genetic profiling,89 optimism persists that similar approaches can be applied to MASLD. Indeed, oligonucleotide-based therapies in the form of antisense oligonucleotide or small interfering RNA (siRNA) that target PNPLA3 and HSD17B13 are already being evaluated in phase 1-2 clinical trials for MASH currently.90 Early reports do suggest some encouraging results; recently, early phase data pertaining to JNJ-75220795 (also known as ARO-PNPLA3), a hepatocyte-targeted N-acetylgalactosamine–conjugated siRNA against PNPLA3, demonstrated reduction of liver fat content in homozygous subjects for the PNPLA3 I148M variant.91 The full results from these trials will help to further inform and guide emerging therapeutic strategic approaches in precision medicine. More tools are urgently needed to enable precision medicine as well as personalized medicine to be translated into clinical practice.

CONCLUSION

MASLD is the most common chronic liver disease at present, with increasing prevalence and clinical burden worldwide. The clinical phenotype is affected by a multitude of factors, of which genetic factors play a substantial role. While significant progress has been made in understanding the genomics of MASLD, more needs to be clarified.

Awareness of these factors, how they are related to the underlying pathogenesis and determining their functional impact is crucial to help identify high-risk patients and pave the way to develop novel precision medicine-orientated interventions.

CONFLICTS OF INTEREST

No potential conflict of interest relevant to this article was reported.

AUTHOR CONTRIBUTIONS

Study concept and design: all authors. Data acquisition: all authors. Data analysis and interpretation: all authors. Drafting of the manuscript: all authors. Critical revision of the manuscript for important intellectual content: all authors. Approval of final manuscript: all authors.

Fig 1.

Figure 1.Genetic loci involved in the susceptibility and pathophysiology of fatty liver disease. PNPLA3, patatin-like phospholipase domain-containing protein 3; HSD17B13, hydroxysteroid 17-beta dehydrogenase 13; VLDL, very low-density lipoprotein; APOB, apolipoprotein B; MBOAT7, membrane bound O-acyltransferase domain-containing 7; GCKR, glucokinase regulator; TM6SF2, transmembrane 6 superfamily member 2; MASLD, metabolic dysfunction-associated steatotic liver disease.
Gut and Liver 2025; 19: 8-18https://doi.org/10.5009/gnl240407

Table 1 Genetic Variants Associated with MASLD

GeneGenetic variantAffected proteinEffectPathophysiologyEffect on hepatic steatosisEffect on NASHEffect on fibrosis/cirrhosisEffect on HCCMortalityReference
PNPLA3rs738409 C>GI148M

Complex

Gain of function and also loss of function

Lipid droplet remodeling18-24
TM6SF2rs58542926 G>AE167KLoss of functionInhibits secretion of VLDL in hepatocytes-25-29
MBOAT7rs641738 C>TLysophosphatidylinositol-acyltransferase 1 (LPIAT1)DownregulationPhospholipid remodeling-30-33
GCRK

rs780094 C>T

rs1260326 C>T

Intronic variant

P446L

Loss of functionIncreases de novo lipogenesis--34-37
HSD17B13*rs72613567 T>TASplice donor variantLoss of functionLipid droplet remodeling-38-41

MASLD, metabolic dysfunction-associated steatotic liver disease; NASH, nonalcoholic steatohepatitis; HCC, hepatocellular carcinoma; VLDL, very low-density lipoprotein.

*There are many variants within the HSD17B13 gene, including rs6834314 A>G, rs62305723 G>A, rs10433937 T>A, T>C, T>G, rs10433879 G>C, rs61748262 C>A, C>T.


Table 2 Risk Prediction Scores for Liver-Related Outcomes

ScoreGenetic variant and components of scoreMethodCohortPredicted outcomeAUROCDiagnostic thresholdOdds ratioSensitivitySpecificityReference
Genetic risk scorePNPLA3, TM6SF2, HSD17B13Blood testGeneral (European) population

Cirrhosis

HCC

NACombined GRS calculated as sum of risk-increasing alleles with range: 0-6

Up to 12 for cirrhosis

Up to 29 for HCC

NANA82
Cirrhosis polygenic risk scorePNPLA3, TM6SF2, HSD17B13, MBOAT7, GCKR, TRIB1, APOE, GPAMBlood testNAFLD with diabetes and indeterminate FIB-4 (1.3–2.67)Cirrhosis or portal hypertensive complications0.73NANANANA80
PNPLA3-rs738409-GG genotypePNPLA30.78Presence of GG genotypeNA0.300.93
HCC risk score*Age, sex, obesity, T2DM, severe fibrosis, number of risk alleles (PNPLA3, TM6SF2 MBOAT7)Composite score with clinical, metabolic and genetic factorsNAFLDHCC0.96NA13.40.960.8932
Polygenic risk score–hepatic fat content (PRS-HFC)PNPLA3, TM6SF2, MBOAT7, GCKRBlood testNAFLDHCC0.640.5323.00.430.8078
Polygenic risk score considering 5 risk variants (PRS-5)PNPLA3, TM6SF2, MBOAT7, GCKR, HSD17B13Blood testNAFLDHCC0.650.4952.90.430.7978
Genetic and Metabolic Staging (GEMS) scoring system

PNPLA3, HSD17B13, TM6SF2, male sex,

diabetes, low HDL

Composite score of clinical, metabolic and genetic variablesNAFLD and FIB-4 ≥ 1.3Liver-related events0.87

Range from 0 to 10

0=total absence of risk of LREs 10=highest risk of LREs, then sub-categorized into five classes: 0–5, 5–6, 6–7, 7–8, 8–10

Risk of LREs increased from 4% in GEMS 0–5, to 91% in GEMS 8–10NANA81

AUROC, area under the curve; HCC, hepatocellular carcinoma; NA, not available; GRS, genetic risk score; NAFLD, nonalcoholic fatty liver disease; FIB-4, fibrosis-4 score; T2DM, type 2 diabetes mellitus; HDL, high-density lipoprotein; LRE, liver related events.

*A combined risk score considering acquired and genetic risk factors was developed to predict HCC: 1/(1+e− ((−12.588+(0.162×age)+(0.404×sex: 1 if male, −1 if female)+(0.259×obesity: 1 present, −1 absent)+(0.587×T2DM: 1 present, −1 absent)+(1.299×severe fibrosis: 1 yes, −1 no)+(0.442×number of risk alleles))); The GEMS score is calculated using the following formula: 1.163–0.438(PNPLA3 CG/GG)+0.421(male sex)–0.413(diabetes)+2.635(55≤age<65)+2.888(age>65)+0.632(low HDL)+0.668(albumin <4 g/dL)+1.935(110,000/mm33)+2.605(platelets<110,000/mm3)+0.602(HSD17B13 TTA/TATA)+0.661(TM6SF2 CT/TT)–1.146(interaction PNPLA3 CG/GG and male sex)+1.641(interaction PNPLA3 CG/GG and diabetes).


References

  1. El-Kassas M, Cabezas J, Coz PI, Zheng MH, Arab JP, Awad A. Nonalcoholic fatty liver disease: current global burden. Semin Liver Dis 2022;42:401-412.
    Pubmed CrossRef
  2. Younossi ZM, Golabi P, Paik JM, Henry A, Van Dongen C, Henry L. The global epidemiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH): a systematic review. Hepatology 2023;77:1335-1347.
    Pubmed KoreaMed CrossRef
  3. Goh GB, McCullough AJ. Natural history of nonalcoholic fatty liver disease. Dig Dis Sci 2016;61:1226-1233.
    Pubmed KoreaMed CrossRef
  4. Estes C, Anstee QM, Arias-Loste MT, et al. Modeling NAFLD disease burden in China, France, Germany, Italy, Japan, Spain, United Kingdom, and United States for the period 2016-2030. J Hepatol 2018;69:896-904.
    Pubmed CrossRef
  5. Estes C, Razavi H, Loomba R, Younossi Z, Sanyal AJ. Modeling the epidemic of nonalcoholic fatty liver disease demonstrates an exponential increase in burden of disease. Hepatology 2018;67:123-133.
    Pubmed KoreaMed CrossRef
  6. Younossi ZM, Blissett D, Blissett R, et al. The economic and clinical burden of nonalcoholic fatty liver disease in the United States and Europe. Hepatology 2016;64:1577-1586.
    Pubmed CrossRef
  7. Schattenberg JM, Lazarus JV, Newsome PN, et al. Disease burden and economic impact of diagnosed non-alcoholic steatohepatitis in five European countries in 2018: a cost-of-illness analysis. Liver Int 2021;41:1227-1242.
    Pubmed KoreaMed CrossRef
  8. Goh GB, Kwan C, Lim SY, et al. Perceptions of non-alcoholic fatty liver disease: an Asian community-based study. Gastroenterol Rep (Oxf) 2016;4:131-135.
    Pubmed KoreaMed CrossRef
  9. Powell EE, Wong VW, Rinella M. Non-alcoholic fatty liver disease. Lancet 2021;397:2212-2224.
    Pubmed CrossRef
  10. Dongiovanni P, Anstee QM, Valenti L. Genetic predisposition in NAFLD and NASH: impact on severity of liver disease and response to treatment. Curr Pharm Des 2013;19:5219-5238.
    Pubmed KoreaMed CrossRef
  11. Caussy C, Soni M, Cui J, et al. Nonalcoholic fatty liver disease with cirrhosis increases familial risk for advanced fibrosis. J Clin Invest 2017;127:2697-2704.
    Pubmed KoreaMed CrossRef
  12. Loomba R, Schork N, Chen CH, et al. Heritability of hepatic fibrosis and steatosis based on a prospective twin study. Gastroenterology 2015;149:1784-1793.
    Pubmed KoreaMed CrossRef
  13. Guerrero R, Vega GL, Grundy SM, Browning JD. Ethnic differences in hepatic steatosis: an insulin resistance paradox?. Hepatology 2009;49:791-801.
    Pubmed KoreaMed CrossRef
  14. Ebrahimi F, Hagström H, Sun J, et al. Familial coaggregation of MASLD with hepatocellular carcinoma and adverse liver outcomes: nationwide multigenerational cohort study. J Hepatol 2023;79:1374-1384.
    Pubmed CrossRef
  15. Chen Y, Du X, Kuppa A, et al. Genome-wide association meta-analysis identifies 17 loci associated with nonalcoholic fatty liver disease. Nat Genet 2023;55:1640-1650.
    Pubmed KoreaMed CrossRef
  16. Xiao L, Li Y, Hong C, et al. Polygenic risk score of metabolic dysfunction-associated steatotic liver disease amplifies the health impact on severe liver disease and metabolism-related outcomes. J Transl Med 2024;22:650.
    Pubmed KoreaMed CrossRef
  17. Romeo S, Kozlitina J, Xing C, et al. Genetic variation in PNPLA3 confers susceptibility to nonalcoholic fatty liver disease. Nat Genet 2008;40:1461-1465.
    Pubmed KoreaMed CrossRef
  18. Speliotes EK, Butler JL, Palmer CD, et al. PNPLA3 variants specifically confer increased risk for histologic nonalcoholic fatty liver disease but not metabolic disease. Hepatology 2010;52:904-912.
    Pubmed KoreaMed CrossRef
  19. Rotman Y, Koh C, Zmuda JM, Kleiner DE, Liang TJ; NASH CRN. The association of genetic variability in patatin-like phospholipase domain-containing protein 3 (PNPLA3) with histological severity of nonalcoholic fatty liver disease. Hepatology 2010;52:894-903.
    Pubmed KoreaMed CrossRef
  20. Valenti L, Al-Serri A, Daly AK, et al. Homozygosity for the patatin-like phospholipase-3/adiponutrin I148M polymorphism influences liver fibrosis in patients with nonalcoholic fatty liver disease. Hepatology 2010;51:1209-1217.
    Pubmed CrossRef
  21. Pennisi G, Pipitone RM, Cammà C, et al. PNPLA3 rs738409 C>G variant predicts fibrosis progression by noninvasive tools in nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol 2021;19:1979-1981.
    Pubmed CrossRef
  22. Singal AG, Manjunath H, Yopp AC, et al. The effect of PNPLA3 on fibrosis progression and development of hepatocellular carcinoma: a meta-analysis. Am J Gastroenterol 2014;109:325-334.
    Pubmed KoreaMed CrossRef
  23. Liu YL, Patman GL, Leathart JB, et al. Carriage of the PNPLA3 rs738409 C >G polymorphism confers an increased risk of non-alcoholic fatty liver disease associated hepatocellular carcinoma. J Hepatol 2014;61:75-81.
    Pubmed CrossRef
  24. Grimaudo S, Pipitone RM, Pennisi G, et al. Association between PNPLA3 rs738409 C>G variant and liver-related outcomes in patients with nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol 2020;18:935-944.
    Pubmed CrossRef
  25. Carlsson B, Lindén D, Brolén G, et al. Review article: the emerging role of genetics in precision medicine for patients with non-alcoholic steatohepatitis. Aliment Pharmacol Ther 2020;51:1305-1320.
    Pubmed KoreaMed CrossRef
  26. Kozlitina J, Smagris E, Stender S, et al. Exome-wide association study identifies a TM6SF2 variant that confers susceptibility to nonalcoholic fatty liver disease. Nat Genet 2014;46:352-356.
    Pubmed KoreaMed CrossRef
  27. Luo F, Oldoni F, Das A. TM6SF2: a novel genetic player in nonalcoholic fatty liver and cardiovascular disease. Hepatol Commun 2022;6:448-460.
    Pubmed KoreaMed CrossRef
  28. Liu YL, Reeves HL, Burt AD, et al. TM6SF2 rs58542926 influences hepatic fibrosis progression in patients with non-alcoholic fatty liver disease. Nat Commun 2014;5:4309.
    Pubmed KoreaMed CrossRef
  29. Chen X, Zhou P, De L, Li B, Su S. The roles of transmembrane 6 superfamily member 2 rs58542926 polymorphism in chronic liver disease: a meta-analysis of 24,147 subjects. Mol Genet Genomic Med 2019;7:e824.
    Pubmed KoreaMed CrossRef
  30. Luukkonen PK, Zhou Y, Hyötyläinen T, et al. The MBOAT7 variant rs641738 alters hepatic phosphatidylinositols and increases severity of non-alcoholic fatty liver disease in humans. J Hepatol 2016;65:1263-1265.
    Pubmed CrossRef
  31. Mancina RM, Dongiovanni P, Petta S, et al. The MBOAT7-TMC4 variant rs641738 increases risk of nonalcoholic fatty liver disease in individuals of European descent. Gastroenterology 2016;150:1219-1230.
    Pubmed KoreaMed CrossRef
  32. Donati B, Dongiovanni P, Romeo S, et al. MBOAT7 rs641738 variant and hepatocellular carcinoma in non-cirrhotic individuals. Sci Rep 2017;7:4492.
    Pubmed KoreaMed CrossRef
  33. Teo K, Abeysekera KW, Adams L, et al. rs641738C>T near MBOAT7 is associated with liver fat, ALT and fibrosis in NAFLD: a meta-analysis. J Hepatol 2021;74:20-30.
    Pubmed KoreaMed CrossRef
  34. Hernaez R, McLean J, Lazo M, et al. Association between variants in or near PNPLA3, GCKR, and PPP1R3B with ultrasound-defined steatosis based on data from the third National Health and Nutrition Examination Survey. Clin Gastroenterol Hepatol 2013;11:1183-1190.
    Pubmed KoreaMed CrossRef
  35. Santoro N, Zhang CK, Zhao H, et al. Variant in the glucokinase regulatory protein (GCKR) gene is associated with fatty liver in obese children and adolescents. Hepatology 2012;55:781-789.
    Pubmed KoreaMed CrossRef
  36. Kawaguchi T, Shima T, Mizuno M, et al. Risk estimation model for nonalcoholic fatty liver disease in the Japanese using multiple genetic markers. PLoS One 2018;13:e0185490.
    Pubmed KoreaMed CrossRef
  37. Tan HL, Zain SM, Mohamed R, et al. Association of glucokinase regulatory gene polymorphisms with risk and severity of non-alcoholic fatty liver disease: an interaction study with adiponutrin gene. J Gastroenterol 2014;49:1056-1064.
    Pubmed CrossRef
  38. Abul-Husn NS, Cheng X, Li AH, et al. A protein-truncating HSD17B13 variant and protection from chronic liver disease. N Engl J Med 2018;378:1096-1106.
    Pubmed KoreaMed CrossRef
  39. Pirola CJ, Garaycoechea M, Flichman D, et al. Splice variant rs72613567 prevents worst histologic outcomes in patients with nonalcoholic fatty liver disease. J Lipid Res 2019;60:176-185.
    Pubmed KoreaMed CrossRef
  40. Yang J, Trépo E, Nahon P, et al. A 17-beta-hydroxysteroid dehydrogenase 13 variant protects from hepatocellular carcinoma development in alcoholic liver disease. Hepatology 2019;70:231-240.
    Pubmed CrossRef
  41. Gellert-Kristensen H, Nordestgaard BG, Tybjaerg-Hansen A, Stender S. High risk of fatty liver disease amplifies the alanine transaminase-lowering effect of a HSD17B13 variant. Hepatology 2020;71:56-66.
    Pubmed CrossRef
  42. Jonas W, Schürmann A. Genetic and epigenetic factors determining NAFLD risk. Mol Metab 2021;50:101111.
    Pubmed KoreaMed CrossRef
  43. Pingitore P, Romeo S. The role of PNPLA3 in health and disease. Biochim Biophys Acta Mol Cell Biol Lipids 2019;1864:900-906.
    Pubmed CrossRef
  44. Sliz E, Sebert S, Würtz P, et al. NAFLD risk alleles in PNPLA3, TM6SF2, GCKR and LYPLAL1 show divergent metabolic effects. Hum Mol Genet 2018;27:2214-2223.
    Pubmed KoreaMed CrossRef
  45. Luukkonen PK, Nick A, Hölttä-Vuori M, et al. Human PNPLA3-I148M variant increases hepatic retention of polyunsaturated fatty acids. JCI Insight 2019;4:e127902.
    Pubmed KoreaMed CrossRef
  46. Wang Y, Kory N, BasuRay S, Cohen JC, Hobbs HH. PNPLA3, CGI-58, and inhibition of hepatic triglyceride hydrolysis in mice. Hepatology 2019;69:2427-2441.
    Pubmed KoreaMed CrossRef
  47. Mitsche MA, Hobbs HH, Cohen JC. Patatin-like phospholipase domain-containing protein 3 promotes transfer of essential fatty acids from triglycerides to phospholipids in hepatic lipid droplets. J Biol Chem 2018;293:6958-6968.
    Pubmed KoreaMed CrossRef
  48. BasuRay S, Smagris E, Cohen JC, Hobbs HH. The PNPLA3 variant associated with fatty liver disease (I148M) accumulates on lipid droplets by evading ubiquitylation. Hepatology 2017;66:1111-1124.
    Pubmed KoreaMed CrossRef
  49. Johnson SM, Bao H, McMahon CE, et al. PNPLA3 is a triglyceride lipase that mobilizes polyunsaturated fatty acids to facilitate hepatic secretion of large-sized very low-density lipoprotein. Nat Commun 2024;15:4847.
    Pubmed KoreaMed CrossRef
  50. Yang A, Mottillo EP, Mladenovic-Lucas L, Zhou L, Granneman JG. Dynamic interactions of ABHD5 with PNPLA3 regulate triacylglycerol metabolism in brown adipocytes. Nat Metab 2019;1:560-569.
    Pubmed KoreaMed CrossRef
  51. Mondul A, Mancina RM, Merlo A, et al. PNPLA3 I148M variant influences circulating retinol in adults with nonalcoholic fatty liver disease or obesity. J Nutr 2015;145:1687-1691.
    Pubmed KoreaMed CrossRef
  52. Salameh H, Hanayneh MA, Masadeh M, et al. PNPLA3 as a genetic determinant of risk for and severity of non-alcoholic fatty liver disease spectrum. J Clin Transl Hepatol 2016;4:175-191.
    CrossRef
  53. Sookoian S, Pirola CJ. Meta-analysis of the influence of I148M variant of patatin-like phospholipase domain containing 3 gene (PNPLA3) on the susceptibility and histological severity of nonalcoholic fatty liver disease. Hepatology 2011;53:1883-1894.
    Pubmed CrossRef
  54. Unalp-Arida A, Ruhl CE. Patatin-like phospholipase domain-containing protein 3 I148M and liver fat and fibrosis scores predict liver disease mortality in the U.S. population. Hepatology 2020;71:820-834.
    Pubmed CrossRef
  55. Meffert PJ, Repp KD, Völzke H, et al. The PNPLA3 SNP rs738409:G allele is associated with increased liver disease-associated mortality but reduced overall mortality in a population-based cohort. J Hepatol 2018;68:858-860.
    Pubmed CrossRef
  56. Kantartzis K, Peter A, Machicao F, et al. Dissociation between fatty liver and insulin resistance in humans carrying a variant of the patatin-like phospholipase 3 gene. Diabetes 2009;58:2616-2623.
    Pubmed KoreaMed CrossRef
  57. Anstee QM, Day CP. The genetics of nonalcoholic fatty liver disease: spotlight on PNPLA3 and TM6SF2. Semin Liver Dis 2015;35:270-290.
    Pubmed CrossRef
  58. Huang Y, He S, Li JZ, et al. A feed-forward loop amplifies nutritional regulation of PNPLA3. Proc Natl Acad Sci U S A 2010;107:7892-7897.
    Pubmed KoreaMed CrossRef
  59. Stender S, Kozlitina J, Nordestgaard BG, Tybjærg-Hansen A, Hobbs HH, Cohen JC. Adiposity amplifies the genetic risk of fatty liver disease conferred by multiple loci. Nat Genet 2017;49:842-847.
    Pubmed KoreaMed CrossRef
  60. Romeo S, Sentinelli F, Dash S, et al. Morbid obesity exposes the association between PNPLA3 I148M (rs738409) and indices of hepatic injury in individuals of European descent. Int J Obes (Lond) 2010;34:190-194.
    Pubmed CrossRef
  61. Palmer CN, Maglio C, Pirazzi C, et al. Paradoxical lower serum triglyceride levels and higher type 2 diabetes mellitus susceptibility in obese individuals with the PNPLA3 148M variant. PLoS One 2012;7:e39362.
    Pubmed KoreaMed CrossRef
  62. Lin H, Wong GL, Whatling C, et al. Association of genetic variations with NAFLD in lean individuals. Liver Int 2022;42:149-160.
    Pubmed CrossRef
  63. Dongiovanni P, Petta S, Maglio C, et al. Transmembrane 6 superfamily member 2 gene variant disentangles nonalcoholic steatohepatitis from cardiovascular disease. Hepatology 2015;61:506-514.
    Pubmed CrossRef
  64. Palmer ND, Musani SK, Yerges-Armstrong LM, et al. Characterization of European ancestry nonalcoholic fatty liver disease-associated variants in individuals of African and Hispanic descent. Hepatology 2013;58:966-975.
    Pubmed KoreaMed CrossRef
  65. Pirola CJ, Sookoian S. The dual and opposite role of the TM6SF2-rs58542926 variant in protecting against cardiovascular disease and conferring risk for nonalcoholic fatty liver: a meta-analysis. Hepatology 2015;62:1742-1756.
    Pubmed CrossRef
  66. Li XY, Liu Z, Li L, Wang HJ, Wang H. TM6SF2 rs58542926 is related to hepatic steatosis, fibrosis and serum lipids both in adults and children: a meta-analysis. Front Endocrinol (Lausanne) 2022;13:1026901.
    Pubmed KoreaMed CrossRef
  67. Fuchsberger C, Flannick J, Teslovich TM, et al. The genetic architecture of type 2 diabetes. Nature 2016;536:41-47.
    Pubmed KoreaMed CrossRef
  68. Matsuda S, Inoue T, Lee HC, et al. Member of the membrane-bound O-acyltransferase (MBOAT) family encodes a lysophospholipid acyltransferase with broad substrate specificity. Genes Cells 2008;13:879-888.
    Pubmed CrossRef
  69. Meroni M, Longo M, Fracanzani AL, Dongiovanni P. MBOAT7 down-regulation by genetic and environmental factors predisposes to MAFLD. EBioMedicine 2020;57:102866.
    Pubmed KoreaMed CrossRef
  70. Caddeo A, Spagnuolo R, Maurotti S. MBOAT7 in liver and extrahepatic diseases. Liver Int 2023;43:2351-2364.
    Pubmed CrossRef
  71. Eslam M, Valenti L, Romeo S. Genetics and epigenetics of NAFLD and NASH: clinical impact. J Hepatol 2018;68:268-279.
    Pubmed CrossRef
  72. Raimondo A, Rees MG, Gloyn AL. Glucokinase regulatory protein: complexity at the crossroads of triglyceride and glucose metabolism. Curr Opin Lipidol 2015;26:88-95.
    Pubmed KoreaMed CrossRef
  73. Beer NL, Tribble ND, McCulloch LJ, et al. The P446L variant in GCKR associated with fasting plasma glucose and triglyceride levels exerts its effect through increased glucokinase activity in liver. Hum Mol Genet 2009;18:4081-4088.
    Pubmed KoreaMed CrossRef
  74. Su W, Mao Z, Liu Y, et al. Role of HSD17B13 in the liver physiology and pathophysiology. Mol Cell Endocrinol 2019;489:119-125.
    Pubmed CrossRef
  75. Ma Y, Belyaeva OV, Brown PM, et al. 17-Beta hydroxysteroid dehydrogenase 13 is a hepatic retinol dehydrogenase associated with histological features of nonalcoholic fatty liver disease. Hepatology 2019;69:1504-1519.
    Pubmed KoreaMed CrossRef
  76. Seko Y, Yamaguchi K, Tochiki N, et al. Attenuated effect of PNPLA3 on hepatic fibrosis by HSD17B13 in Japanese patients with non-alcoholic fatty liver disease. Liver Int 2020;40:1686-1692.
    Pubmed CrossRef
  77. Vilar-Gomez E, Pirola CJ, Sookoian S, Wilson LA, Liang T, Chalasani N. The protection conferred by HSD17B13 rs72613567 polymorphism on risk of steatohepatitis and fibrosis may be limited to selected subgroups of patients with NAFLD. Clin Transl Gastroenterol 2021;12:e00400.
    Pubmed KoreaMed CrossRef
  78. Bianco C, Jamialahmadi O, Pelusi S, et al. Non-invasive stratification of hepatocellular carcinoma risk in non-alcoholic fatty liver using polygenic risk scores. J Hepatol 2021;74:775-782.
    Pubmed KoreaMed CrossRef
  79. Thomas CE, Diergaarde B, Kuipers AL, et al. NAFLD polygenic risk score and risk of hepatocellular carcinoma in an East Asian population. Hepatol Commun 2022;6:2310-2321.
    Pubmed KoreaMed CrossRef
  80. Chen VL, Oliveri A, Miller MJ, et al. PNPLA3 genotype and diabetes identify patients with nonalcoholic fatty liver disease at high risk of incident cirrhosis. Gastroenterology 2023;164:966-977.
    Pubmed KoreaMed CrossRef
  81. Pennisi G, Pipitone RM, Enea M, et al. A Genetic and Metabolic Staging system for predicting the outcome of nonalcoholic fatty liver disease. Hepatol Commun 2022;6:1032-1044.
    Pubmed KoreaMed CrossRef
  82. Gellert-Kristensen H, Richardson TG, Davey Smith G, Nordestgaard BG, Tybjaerg-Hansen A, Stender S. Combined effect of PNPLA3, TM6SF2, and HSD17B13 variants on risk of cirrhosis and hepatocellular carcinoma in the general population. Hepatology 2020;72:845-856.
    Pubmed CrossRef
  83. De Vincentis A, Tavaglione F, Jamialahmadi O, et al. A polygenic risk score to refine risk stratification and prediction for severe liver disease by clinical fibrosis scores. Clin Gastroenterol Hepatol 2022;20:658-673.
    Pubmed CrossRef
  84. Shen J, Wong GL, Chan HL, et al. PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease. J Gastroenterol Hepatol 2015;30:139-146.
    Pubmed CrossRef
  85. Seko Y, Yamaguchi K, Tochiki N, et al. The effect of genetic polymorphism in response to body weight reduction in Japanese patients with nonalcoholic fatty liver disease. Genes (Basel) 2021;12:628.
    Pubmed KoreaMed CrossRef
  86. Aller R, Laserna C, Rojo MÁ, et al. Role of the PNPLA3 polymorphism rs738409 on silymarin + vitamin E response in subjects with non-alcoholic fatty liver disease. Rev Esp Enferm Dig 2018;110:634-640.
    Pubmed CrossRef
  87. Chen Y, Yan X, Xu X, Yuan S, Xu F, Liang H. PNPLA3 I148M is involved in the variability in anti-NAFLD response to exenatide. Endocrine 2020;70:517-525.
    Pubmed CrossRef
  88. Nelson MR, Tipney H, Painter JL, et al. The support of human genetic evidence for approved drug indications. Nat Genet 2015;47:856-860.
    Pubmed CrossRef
  89. Sabatine MS, Giugliano RP, Keech AC, et al. Evolocumab and clinical outcomes in patients with cardiovascular disease. N Engl J Med 2017;376:1713-1722.
    Pubmed CrossRef
  90. Lindén D, Romeo S. Therapeutic opportunities for the treatment of NASH with genetically validated targets. J Hepatol 2023;79:1056-1064.
    Pubmed CrossRef
  91. Fabbrini E, Rady B, Koshkina A, et al. Phase 1 trials of PNPLA3 siRNA in I148M homozygous patients with MAFLD. N Engl J Med 2024;391:475-476.
    Pubmed CrossRef
Gut and Liver

Vol.19 No.1
January, 2025

pISSN 1976-2283
eISSN 2005-1212

qrcode
qrcode

Share this article on :

  • line

Popular Keywords

Gut and LiverQR code Download
qr-code

Editorial Office