ANALYSIS OF GENES FOR BILIRUBIN UDP-GLUCURONOSYLTRANSFERASE IN GILBERTS-SYNDROME

Gilbert's and Crigler-Najjar syndromes are characterised by unconjugat ed hyperbilirubinaemia due to complete and partial absence of bilirubi n UDP-glucuronosyltransferase (UGT). Nucleotide sequences of the genes for bilirubin UGT were analysed in six patients with Gilbert's syndro me. All patients had a missense mutation caused by a single nucleotide substitution and the mutations were heterozygous. In addition, relati ves of patients with Crigler-Najjar syndrome types I and II, and of th ose with Gilbert's syndrome were analysed. All ten relatives with mild hyperbilirubinaemia were heterozygotes with respect to each defective allele. These results suggest that Gilbert's syndrome is inherited as a dominant trait.