Non-alcoholic fatty liver disease (NAFLD) is commonly diagnosed in patients with obesity and type 2 diabetes mellitus (T2DM), and has been associated with the single nucleotide polymorphism (SNP) rs738409 in the PNPLA3 gene.
NAFLD is further favored by the patatin-like phospholipase domain-containing 3 (PNPLA3) p.I148M, transmembrane 6 superfamily member 2 (TM6SF2) p.E167K, and membrane-bound O-acyltransferase domain containing 7 (MBOAT7) rs641738 variants.
NAFLD was strongly associated with three genetic variants, TM6SF2 rs58542926, PNPLA3 rs738409 and GCKR rs1260326, and more slightly with ELOVL2 rs2236212, in obese children and adolescents.
A discrete trait analysis of NAFLD showed that rs58542926 was associated with a modest risk of fatty liver (P = 0.038; odds ratio [OR]: 1.37; 95% confidence interval [CI]: 1.02-1.84); nevertheless, conditioning on patatin-like phospholipase domain-containing 3 (PNPLA3)-rs738409 abolished this effect.
A genetic polymorphism in rs738409, in the patatin-like phospholipase domain-containing 3 gene (PNPLA3), is strongly associated with appearance of in NAFLD.
A genetic variant of patatin-like phospholipase domain-containing 3 (PNPLA3-I14</span>8M) is the most prominent heritable factor associated with NAFLD.
A nonsynonymous single nucleotide polymorphism rs738409 (I148M) in patatin-like phospholipase domain-containing protein 3 (PNPLA3) predisposes susceptibility to NAFLD; however, its association with steatosis grade is inconsistent in the literature.
A recent genome-wide association study identified a genetic variant in the patatin-like phospholipase-3 (PNPLA3) gene (rs738409 C>G) associated with steatosis that was further demonstrated to influence severity of fibrosis in nonalcoholic fatty liver disease.
A sequence polymorphism (rs738409, I148M) in patatin-like phospholipid domain containing protein 3 (PNPLA3) is strongly associated with nonalcoholic fatty liver disease (NAFLD), but the mechanistic basis for this association remains enigmatic.
A single nucleotide polymorphism (SNP) of the patatin-like phospholipase-3 (PNPLA3)/adiponutrin gene (rs738409 C>G) is strongly associated with nonalcoholic fatty liver disease; to our knowledge, no data are available on the impact of this PNPLA3 SNP on liver and metabolic outcomes during pregnancy in patients with gestational diabetes (GD).
ADPN I148M polymorphism has been consistently reported to play a role in liver-associated diseases, such as alcoholic liver disease, chronic hepatitis C, and liver fat and fibrosis in nonalcoholic fatty liver disease.
After adjusting for sex, age, serum triglycerides, total cholesterol, body mass index, and the PNPLA3 rs738409 polymorphism, the APOC3 rs2070666 A allele was an independent risk factor for NAFLD with an odds ratio (OR) of 3.683 and 95 % confidence interval (CI) of 1.037-13.084.
After adjustment for age, sex, diabetes, and alcohol consumption, the minor allele of rs738409 C/G, a nonsynonymous coding SNP in the patatin-like phospholipase domain-containing protein 3 (PNPLA3) (adiponutrin) gene encoding an Ile148Met change, was associated with steatosis (P = 0.03), portal inflammation (P = 2.5 x 10(-4)), lobular inflammation (P = 0.005), Mallory-Denk bodies (P = 0.015), NAFLD activity score (NAS, P = 0.004), and fibrosis (P = 7.7 x 10(-6)).
Although the PNPLA3 rs738409 GG genotype confers a higher risk of NAFLD, these patients are more sensitive to the beneficial effects of lifestyle modification and should be encouraged to do so.
Among individual variants, rs1260326 in GCKR and rs641738 in MBOAT7 (recessive), rs58542926 in TM6SF2 and rs738409 in PNPLA3 (dominant) emerged as associated to NAFLD, with PNPLA3 rs738409 being the strongest predictor (OR 3.12, 95% CI, 1.8-5.5, P < 0.001).
As compared to those with C/C and C/G at rs738409, C/C and C/T at rs3747206, G/G and G/A at rs4823173, and A/A and A/G at rs2072906, patients in the CHB + NAFLD group with G/G at rs738409, T/T at rs3747206, A/A at rs4823173, and G/G at rs2072906 showed significantly lower serum levels of HBV DNA (P < 0.01-0.05).
As variants in PNPLA3 (I148M) and TM6SF2 (E167K) are associated with nonalcoholic fatty liver disease, we assessed these variants in type 2 diabetes (T2D) patients randomized to receive BIL (n=1822) or GL (n=1270) in three phase 3 trials.
Because PNPLA3 rs738409, GCKR rs780094 and TM6SF2 rs58542926 variants are known to confer susceptibility to NAFLD, we assessed the influence of MBOAT7 rs641738 on hepatic steatosis, and serum levels of CK-18 fragment (a biomarker of hepatocellular injury and apoptosis for NAFLD) after adjusting the effects of PNPLA3, GCKR and TM6SF2 polymorphisms.
By studying the genetic variants of obese Taiwanese children, we confirmed that the genetic variants in GCKR rs780094 and PNPLA3 rs738409, but not in NCAN rs2228603, LYPLAL1 rs12137855, and PPP1R3B rs4240624, are associated with an increased risk of NAFLD.
By summarizing the amount of evidence, this study provided unequivocal evidence of rs738409 as a strong modifier of the natural history of NAFLD in different populations around the world.