In Silico and In Vitro Analyses of PNPLA3 rs738409 C>G Polymorphism in Patients With Non-alcoholic Fatty Liver Disease

The polymorphism associated with liver fat content, which is well-known as PNPLA3 rs738409 (Patatin-like phospholipase domain-containing protein 3), is one of the critical subjects widely investigated in the literature regarding the prevalence of non-alcoholic fatty liver disease (NAFLD) worldwide. The present research aimed to study the bioinformatics investigations of this polymorphism together with the in vitro analyses among patients with NAFLD.

In this case-control study, after performing bioinformatics analysis, the laboratory examination was performed in several steps. Genomic DNA was extracted from the blood of 53 NAFLD patients and 107 subjects with normal liver ultrasounds. PNPLA3 rs738409 was genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. The laboratory test results, including fasting blood sugar, triglyceride, cholesterol, high-density lipoprotein, low-density lipoprotein, alanine aminotransferase, and aspartate aminotransferase were collected from medical records. Finally, statistical analysis was performed using SPSS software, version 18.0.

The frequency of the G allele was 56% and 36% among patients and in the control group, respectively. The frequency of genotypes was 35.8% and 47.7% (CC), 17% and 31.8% (CG), 47.2% and 20.6% (GG) in patients and control groups, respectively. The adjusted odds ratios for PNPLA3 rs738409 C>G were 3.0 (95% confidence interval [CI]: 1.28-6.98, P=.011) and 0.68 (95% CI: 0.25- 1.83, P = .44) for GG and CG genotypes, respectively.

The findings showed the association between the GG genotype and the presence of NAFLD. Furthermore, the bioinformatics findings suggested the probable risk of the disease incidence regarding the change of hydropathic characteristics resulting from the amino acid substitution.