Polymorphisms of microsomal triglyceride transfer protein gene and phosphatidylethanolamine N-methyltransferase gene in alcoholic and nonalcoholic fatty liver disease in Koreans

Abstract
The pathogenesis of fatty liver is likely to depend on a complex interaction of environmental and genetic factors. We investigated a large-scale analysis of the association between microsomal triglyceride transfer protein (MTTP) and phosphatidylethanolamine N-methyltransferase (PEMT) polymorphism in alcoholic and nonalcoholic fatty liver disease. Five hundred and eighty-eight patients who visited the health promotion center were enrolled. To elucidate the possible role of genetic variation affecting triglyceride metabolism in fatty liver disease, the MTTP-I128T and PEMT-V175M polymorphisms were studied. The I/I genotype and I allele frequency of MTTP polymorphism with alcoholic fatty liver was significantly higher than that of the normal control group (P=0.026 vs. 0.005). Genotype and allele frequency of PEMT, however, did not show a significant difference between control and fatty liver. I/I genotype of MTTP gene frequency in the drinkers with fatty livers was 85.4%, which was significantly higher than that in the drinkers without fatty liver, which was 68.4% (P=0.013). With regard to biochemical indicators, the alanine aminotransferase value of the I/I group was significantly higher than that of the I/T and T/T groups (P=0.04). Asparate aminotransferase, gamma-glutamyl transpeptidase, triglyceride, apolipoprotein B, and glucose concentration tended to be lower in the I/T and T/T groups than in the I/I group, but no statistically significant difference was found. In this study, MTTP-I128T polymorphism is associated with central obesity, elevated liver enzymes, and alcoholic fatty liver disease.