The Membrane-bound O-Acyltransferase7 rs641738 Variant in Pediatric Nonalcoholic Fatty Liver Disease.

BACKGROUND: The rs641738 polymorphism in the membrane-bound O-acyltransferase domain containing protein 7 (MBOAT7) gene has been associated with increased risk of nonalcoholic fatty liver disease (NAFLD).

OBJECTIVES: To investigate the association between the MBOAT7 rs641738 polymorphism and both hepatic steatosis and biochemical markers of liver damage and to evaluate the potential additive effect of this variant and the I148M patatin-like phospholipase domain-containing 3 (PNPLA3) and the rs58542926 transmembrane 6 superfamily member 2 (TM6SF2) polymorphisms.

METHODS: One thousand and 2 obese children were genotyped for MBOAT7, PNPLA3, and TM6SF2 polymorphisms and underwent anthropometrical, ultrasonographic, and biochemical evaluation. Indirect measurement of liver fibrosis (Pediatric NAFLD Fibrosis Index [PNFI]) and a genetic risk score from these polymorphisms were calculated.

RESULTS: Carriers of the MBOAT7 T allele showed both higher alanine transaminase (ALT) (P = 0.004) and PNFI values (P = 0.04) than noncarriers. These findings were confirmed also for the carriers of the MBOAT7 T allele polymorphism with hepatic steatosis compared with noncarriers. A higher genetic risk score was associated with higher ALT (P = 0.011) and with an odds ratio (OR) to show elevated ALT of 3.4 (95% CI 1.3-5.5, P = 0.003). Patients belonging to genetic risk score 3 group had an OR to present steatosis of 2.6 (95% CI 1.43-4.83, P = 0.0018) compared with those belonging to lower genetic risk score group.

CONCLUSIONS: We first demonstrated in childhood obesity the role of the MBOAT7 rs641738 variant on serum ALT and the combined effect of the MBOAT7, PNPLA3, and TM6SF2 variants on NAFLD risk. We also provided the first pediatric association of the MBOAT7 polymorphism with indirect markers of liver fibrosis.