Wayward effect of polymorphism (TA)8 in the promoter region of UGT1A1 Gene in a Mexican family

Gilbert syndrome (GS) is a hereditary relatively common benign unconjugated hyperbilirubinaemia. The promoter region of uridine diphosphate glycosyltransferase 1 (UGT1A1) gene contains a normal A (TA) 6TAA element; variations in this motif (A(TA) 7/8TAA) are generally associated with this disorder. This is a report of the varied effects of GS in a Mexican Mestizo family with a non-common (TA) 8 repeat in this population. The proposita and her mother showed (TA) 7/(TA) 8 genotype, while her father and sister were (TA) 6/(TA) 7, but only the proposita showed clinical manifestations. This report supports that the (TA) 7 and (TA) 8 are necessary, but not enough to explain the features of GS. There are probably additional genetic variations ie, the presence of " modifier" genes or one can speculate that an oligogenetic trait can contribute to the expression of the final phenotype