PNPLA3 and TNF-α G238A Genetic Polymorphisms in Egyptian Patients with Different Grades of Severity of NAFLD

Introduction: There is growing evidence that genetic and environmental factors play an important role in the development and progression of non-alcoholic fatty liver disease (NAFLD). We investigated the association of single nucleotide polymorphism (SNP) rs738409 in PNPLA3 gene and TNF-α G238A polymorphism with the development and severity of NAFLD in an overweight and obese Egyptian population. Material and Methods: 100 overweight and obese patients with NAFLD and 30 control subjects were enrolled. All NAFLD patients underwent a confirmatory biopsy. Laboratory investigations included fasting plasma glucose, kidney and liver function tests, liver enzymes, lipid profile and hepatitis markers. Abdominal ultrasound was performed and all subjects were genotyped for (rs738409) PNPLA3 and (rs361525) TNF-α gene polymorphisms using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: The homozygous GG genotype of the PNPLA3 was most frequent among patients with NASH (26%) as compared to borderline NASH (20.5%) and simple steatosis (20%). Higher serum levels of transaminases were observed in NAFLD patients and controls who were carriers of the G allele of rs738409, but this was not statistically significant. Regarding the TNF-α G238A SNP; the frequency of the A allele was significantly higher in NAFLD patients (20%) compared to controls (5%) (p value = 0.006). The highest TNF G allele frequency was observed in the NASH group (88%) and this was statistically significant (p value = 0.009). Conclusion: Our study confirmed the association of the PNPLA3 (rs738409) and TNF-α promoter region G238A polymorphisms with susceptibility to NAFLD and its progression. Corresponding author.