Screening of Family Members of Nonalcoholic Fatty Liver Disease Patients can Detect Undiagnosed Nonalcoholic Fatty Liver Disease Among Them: Is There a Genetic Link?

Background & aims: Nonalcoholic fatty liver disease (NAFLD) has multifactorial origin. Genetic and environmental factors lead to the biology of this complex disorder. In this study, we screened parents of cases with NAFLD and compared them with parents of cases without NAFLD to see its familial aggregation and the role of patatin-like phospholipase domain containing 3 (PNPLA3). Method: It was a cross-sectional study. Parents of probands with NAFLD and without NAFLD were screened with abdominal sonography, anthropometry, blood tests, transient elastography, and PNPLA3 polymorphism. Results: We had enrolled 303 individuals: 51 probands with NAFLD, 50 probands without NAFLD, and their 202 parents. Parents of the NAFLD group had significantly higher metabolic risk factors as compared with parents of the non-NAFLD group. They had a significantly higher rate of fatty liver (P = 0.0001), mean serum aspartate aminotransferase levels (P = 0.011), mean serum alanine aminotransferase levels (P = 0.001),raised fasting and postprandial blood sugar levels, lower mean platelets (P = 0.033) and serum albumin levels (P = 0.005), and higher mean liver stiffness (P = 0.001) on transient elastography. Frequency of PNPLA3 polymorphism within NAFLD group was higher compared to the non-NAFLD group (mutant GG-13.3 vs 3.3%). Similarly, parents of NAFLD group had mutant GG in 15 % versus 5% in parents of non-NAFLD group, (P = 0.105, odds ratio 6), though it was not statistically significant but may be relevant. In this study, offsprings of parents with nonalcoholic steatohepatitis were likely to have GG homozygous allele. A NAFLD16 score based on parent's parameters was calculated to predict the probability of NAFLD occurrence in an overweight obese individual. Conclusion: Screening of parents of individuals with NAFLD will help in the identification of undiagnosed NAFLD cases and other metabolic risk factors among them as there is a familial aggregation of NAFLD. One can predict the occurrence of NAFLD in the next generation using the NAFLD16 score.