UGT1A1 and Hyperbilirubinemia: The UGT1A1 gene encodes the bilirubin uridine diphosphate-glucuronosyltransferase, which is the enzyme responsible for conjugation, detoxification, and clearance of bilirubin, and it has been found among European, African, and Asian populations; mutations of the gene may cause unconjugated hyperbilirubinemia [30,31,32,33,34].