The MBOAT7-TMC4 Variant rs641738 Increases Risk of Nonalcoholic Fatty Liver Disease in Individuals of European Descent

• Published in: Gastroenterology (New York, N.Y. 1943) Vol. 150; no. 5; pp. 1219 - 1230.e6
• Main Authors: Mancina, Rosellina Margherita, Dongiovanni, Paola, Petta, Salvatore, Pingitore, Piero, Meroni, Marica, Rametta, Raffaela, Borén, Jan, Montalcini, Tiziana, Pujia, Arturo, Wiklund, Olov, Hindy, George, Spagnuolo, Rocco, Motta, Benedetta Maria, Pipitone, Rosaria Maria, Craxì, Antonio, Fargion, Silvia, Nobili, Valerio, Käkelä, Pirjo, Kärjä, Vesa, Männistö, Ville, Pihlajamäki, Jussi, Reilly, Dermot F., Castro-Perez, Jose, Kozlitina, Julia, Valenti, Luca, Romeo, Stefano
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2016
• Subjects: Acetyltransferases - genetics; Acetyltransferases - metabolism; Acyltransferases - genetics; Acyltransferases - metabolism; Arachidonic Acid; Biopsy; Cardiology and Cardiovascular Disease; Case-Control Studies; Clinical Medicine; Cross-Sectional Studies; Europe - epidemiology; European Continental Ancestry Group - genetics; Female; Gastroenterologi; Gastroenterologi och hepatologi; Gastroenterology and Hepatology; Genetic Predisposition to Disease; Genome-Wide Association Study; Humans; Kardiologi och kardiovaskulära sjukdomar; Klinisk medicin; Liver - metabolism; Liver - pathology; Liver Cirrhosis - diagnosis; Liver Cirrhosis - ethnology; Liver Cirrhosis - genetics; Liver Cirrhosis - metabolism; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Membrane Proteins - genetics; Membrane Proteins - metabolism; NASH; Non-alcoholic Fatty Liver Disease - diagnosis; Non-alcoholic Fatty Liver Disease - ethnology; Non-alcoholic Fatty Liver Disease - genetics; Non-alcoholic Fatty Liver Disease - metabolism; Phenotype; Phosphatidylinositols - metabolism; PNPLA3; Polymorphism, Genetic; Proton Magnetic Resonance Spectroscopy; Risk Factors; Severity of Illness Index; Texas - epidemiology; TM6SF2; Triglycerides - metabolism; T2DM; NAFLD; OR; CI; MBOAT7; mRNA; IFG; NASH; ER; TMC4; DHS; TM6SF2; HWE; PNPLA3; PI; Arachidonic Acid; BMI; patatin-like phospholipase domain-containing 3; transmembrane 6 superfamily member 2; odds ratio; nonalcoholic steatohepatitis; membrane bound O-acyltransferase domain containing 7; impaired fasting glucose; messenger RNA; type 2 diabetes mellitus; Dallas Heart Study; body mass index; nonalcoholic fatty liver disease; phosphatidylinositol; transmembrane channel-like 4; Hardy-Weinberg equilibrium; confidence interval; endoplasmic reticulum
• ISSN: 0016-5085; 1528-0012; 1528-0012
• DOI: 10.1053/j.gastro.2016.01.032

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of liver damage and is characterized by steatosis. Genetic factors increase risk for progressive NAFLD. A genome-wide association study showed that the rs641738 C>T variant in the locus that contains the membrane bound O-acyltransferase domain-containing 7 gene (MBOAT7, also called LPIAT1) and transmembrane channel-like 4 gene (TMC4) increased the risk for cirrhosis in alcohol abusers. We investigated whether the MBOAT7−TMC4 is a susceptibility locus for the development and progression of NAFLD. We genotyped rs641738 in DNA collected from 3854 participants from the Dallas Heart Study (a multi-ethnic population-based probability sample of Dallas County residents) and 1149 European individuals from the Liver Biopsy Cross-Sectional Cohort. Clinical and anthropometric data were collected, and biochemical and lipidomics were measured in plasma samples from participants. A total of 2736 participants from the Dallas Heart Study also underwent proton magnetic resonance spectroscopy to measure hepatic triglyceride content. In the Liver Biopsy Cross-Sectional Cohort, a total of 1149 individuals underwent liver biopsy to diagnose liver disease and disease severity. The genotype rs641738 at the MBOAT7−TMC4 locus associated with increased hepatic fat content in the 2 cohorts, and with more severe liver damage and increased risk of fibrosis compared with subjects without the variant. MBOAT7, but not TMC4, was found to be highly expressed in the liver. The MBOAT7 rs641738 T allele was associated with lower protein expression in the liver and changes in plasma phosphatidylinositol species consistent with decreased MBOAT7 function. We provide evidence for an association between the MBOAT7 rs641738 variant and the development and severity of NAFLD in individuals of European descent. This association seems to be mediated by changes in the hepatic phosphatidylinositol acyl-chain remodeling.