Gilbert's syndrome is a mild genetic liver disorder characterized by unconjugated hyperbilirubinemia due to defects in the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene.
In bilirubin metabolism, increased destruction of erythrocytes, defect in the function of organic anion transporter polypeptide 2 (OATP2) or UDP-glucuronosyltransferase 1A1 (UGT1A1) may result in unconjugated hyperbilirubinemia.
A total of 115 male adults with unconjugated hyperbilirubinemia were divided into six subgroups according to their glucose-6-phosphate dehydrogenase (G6PD) status (normal and deficient) and UDP-glucuronosyl transferase 1 (UGT1) A1 genotypes (heterozygous variation, compound heterozygous variation and homozygous variation).