Gilbert syndrome associated with β-thalassemia

The authors investigated whether the considerable variability in serum bilirubin levels (STB) found in transfusion-dependent beta -thalassemia, beta -thal intermedia, and heterozygous beta -thalassemia individuals could be related to the coexistence of Gilbert syndrome (GS). The promoter region [A(TA)(n) TAA] of the bilirubin UDP-glucuronosyltransferase gene (UGT1A1) was analyzed in a total of 128 beta -thalassemia individuals (108 transfusion-dependent beta -thal patients, 20 very mild beta -thal intermedia) and in 33,beta -thal heterozygotes. The control group consisted of 70 healthy children with no history of anemia. The frequency of GS genotype (TA)(7)/(TA)(7) did not differ si significantly between the groups studied. A significant difference was observed between Serum bilirubin levels (STB) and GS genotypes (TA)(7)/(TA)(7) and (TA)(6)/(TA)(7) and also between (TA)(7)/(TA)(7) and (TA)(6)/(TA)(6) for all groups examined. These results confirm that the (TA)(7)(TA)(7) CS genotype is one of the factors accounting for the hyperbilirubinemia observed in beta -thalassemia major intermedia, and heterozygous individuals.