Combining I148M and E167K variants to improve risk prediction for nonalcoholic fatty liver disease in Qingdao Han population, China

BACKGROUND: PNPLA3 I148M variant and TM6SF2 E167K variant are recognized as the major genetic modifiers of nonalcoholic fatty liver disease (NAFLD). The present study sought to evaluate the potential additive effect of the two variants on the risk of NAFLD in Qingdao Han Population, China. METHODS: We genotyped PNPLA3 I148M variant and TM6SF2 E167K variant in a cohort of 512 unrelated NAFLD patients and 451 healthy controls by sequencing and polymerase chain reaction analysis. In addition, serum lipid profiles and liver enzymes were determined by standard clinical laboratory methods. RESULTS: The minor allele frequencies were 45.48% for PNPLA3 148 locus G allele and 6.69% for TM6SF2 167 locus T allele. The PNPLA3 I148M variant was significantly associated with the risk of NAFLD in an additive model (CG, OR = 2.092, 95% CI: 1.551–2.820, P = 0.000; GG, OR = 4.566, 95% CI: 3.141–6.638, P = 0.000, respectively). And, our data suggested a strong link between the TM6SF2 E167K variant and the risk of NAFLD in a dominant model (CT + TT, OR = 2.327, 95% CI: 1.542–3.513, P = 0.000). In addition, the increasing of the number of risk alleles were associated with the risk of NAFLD (1 risk allele, OR = 1.687, P = 0.001; 2 risk alleles, OR = 4.326, P = 0.000; 3 risk alleles, OR = 6.018, P = 0.027, respectively). CONCLUSIONS: Combining the I148M and E167K variants in a manner of an additive effect could improve risk prediction for NAFLD in a Qingdao Han Population cohort. TRIAL REGISTRATION: Chinese Clinical Trial Register.gov: ChiCTR1800015426.