Gilbert syndrome is a mild hereditary unconjugated hyperbilirubinemia caused by mutations in the bilirubin UDP-glucuronosyltransferase gene (UGT1A1). The mutation, A(TA)7TAA, is thought to be the sole cause of the syndrome in Caucasians, but an enhancer polymorphism (T-3279G) that lowers transcriptional activity has recently been reported. We have tested the linkage of the two mutations in 11 Caucasians and 12 Japanese patients who were homozygous for A(TA)7TAA. All 23 patients were also homozygous for T-3279G, indicating that T-3279G and A(TA)7TAA were linked. The decrease in transcription caused by both mutations together may be essential to the syndrome.
Beutler E, Gelbart T, Demina A (1998) Racial variability in the UDP-glucuronosyltransferase 1 (UGT1A1) promoter: a balanced polymorphism for regulation of bilirubin metabolism? Proc Natl Acad Sci USA 95:8170–8174CrossRefPubMedGoogle Scholar
Bosma PJ, Chowdhury JR, Bakker C, et al (1995) The genetic basis of the reduced expression of bilirubin UDP-glucuronosyltransferase 1 in Gilbert’s syndrome. N Engl J Med 333:1171–1175CrossRefPubMedGoogle Scholar
Maruo Y, Nishizawa K, Sato H, Doida Y, Shimada M (1999) Association of neonatal hyperbilirubinemia with bilirubin UDP-glucuronosyltransferase polymorphism. Pediatrics 103:1224–1227CrossRefPubMedGoogle Scholar
Sugatani J, Yamakawa K, Yoshinari K, et al (2002) Identification of a defect in the UGT1A1 gene promoter and its association with hyperbilirubinemia. Biochem Biophys Res Commun 292:492–497CrossRefPubMedGoogle Scholar
Ueyama H, Koiwai O, Soeda Y, et al (1997) Analysis of the promoter of human bilirubin UDP-glucuronosyltransferase gene (UGT1*1) in relevance to Gilbert’s syndrome. Hepatol Res 9:152–163CrossRefGoogle Scholar