A combinatorial haplotype of the UDP-glucuronosyltransferase 1A1 gene (#60-#IB) increases total bilirubin concentrations in Japanese volunteers.

摘要

To the Editor: UDP-glucuronosyltransferases (UGTs) are a family of enzymes that glucu-ronidate many endogenous and exog- enous substrates (1). Of the UGT1A gene isoforms, UGT1A1 is primarily responsible for glucuronidation of bilirubin (1). In east Asians, 2 well-known genetic variants, A(TA)_6TAA> A(TA)_7TAA (allele ~*28, reduced transcription) and G71R (211G>A, allele ~*6, reduced activity), are causative factors for increased plasma bilirubin concentrations in Gilbert syndrome (1). The ~*28 allele is almost always linked to the ~*60 allele (-3279T>G), with reduced in vitro transcription (2).