Association of patatin-like phospholipase domain-containing protein 3 gene polymorphisms with susceptibility of nonalcoholic fatty liver disease in a Han Chinese population

Abstract

Gene polymorphisms had been found to be associated with increased risk of nonalcoholic fatty liver disease (NAFLD). The aim of the present study was to assess the association between rs2896019 and rs3810622 in PNPLA3 with the susceptibility to NAFLD in Han Chinese population.A total of 384 NAFLD patients and 384 controls were enrolled in the study. Blood samples collected from each subject were used for biochemical index analysis and DNA extraction. Genotyping analyses of PNPLA3 rs2896019 and rs3810622 were performed by real-time PCR methods.Results showed that patients with genotype GG of rs2896019 had a higher incidence of NAFLD than patients with genotypes GT and TT (62.4% vs 52.0% and 43.3%, respectively, P = 0.002), and a higher risk of moderate to severe NAFLD than patients with genotypes GT and TT (60.3% vs 46.2% and 40.2%, respectively, P = 0.03). Furthermore, patients with genotype GG of rs2896019 had higher levels of low-density lipoprotein (LDL, P < 0.001), ALT (P = 0.003), and AST (P = 0.002). Patients with genotype TT of rs3810622 had a higher incidence of NAFLD than patients with genotypes CT and CC (56.7% vs 48.4% and 41.5%, respectively, P = 0.013). Likewise, patients with genotype TT of rs3810622 had higher levels of ALT (P = 0.021) and blood glucose (GLU) (P = 0.034). Haplotype association analysis showed that GT haplotype conferred a statistically significant increased risk for NAFLD (OR = 1.49; 95% CI = 1.20-1.84, P < 0.01).These results suggest that PNPLA3 rs2896019 and rs3810622 polymorphisms significantly contribute to increased NAFLD risk in Han Chinese population.

Figure 1

Correlation between controls and nonalcoholic fatty liver disease patients (NAFLD) group in genotype frequency and frequency of allelic gene at loci rs2896019 and rs3810622 of SNP. (A) Patients with genotype GG had higher incidence of NAFLD than patients with genotype GT and TT (62.4% vs 52.0% and 43.3%, respectively, P = 0.002). (B) The frequency of allele G was higher in NAFLD group than in the controls (40.8% vs 32.2%, P < 0.001). (C) Patients with genotype TT had higher incidence of NAFLD than patients with genotype CT and CC (56.7% vs 48.4% and 41.5%, respectively, P = 0.013). (D) The frequency of allele T was higher in NAFLD group than in the controls (60.2% vs 39.8%, P = 0.015).

Figure 2

Comparison of genotype at loci rs2896019 and rs3810622 of SNP and severity of fatty liver. (A) Patients with genotype GG at locus rs2896019 had higher incidence of moderate to severe NAFLD than patients with genotype GT and TT (60.3% vs 46.2% and 40.2%, respectively, P = 0.03). (B) No significant association was found between genotype frequency of rs3810622 and severity of NAFLD (TT: 50.4% vs CT: 47.2% and CC: 39.0%, respectively, P = 0.34). NAFLD = nonalcoholic fatty liver disease patients, SNP = single nucleotide polymorphism.