TATA box polymorphism in the UDP-glucuronosyltransferase-1 gene promoter and neonatal hyperbilirubinemia

This study analyzed the role of the UDP-glucuronosyltransferase (UCT1A1) pr omoter polymorphism (mutant A[TA](7)TAA versus wild-type A[TA](6)TAA) in th e pathophysiology of non-physiological hyperbilirubinemia, in Caucasian Por tuguese neonates. Typing for the TATA box polymorphism was carried out in a study group consi sting of 77 jaundiced neonates (19 with physiological and 58 with non-physi ological hyperbilirubinemia) and in a background control population consist ing of 100 healthy non-jaundiced Caucasian neonates. In the hyperbilirubinemic group without identified risk factors (n = 54), w e found 50% normal homozygotes ([TA](6)/[TA](6)), 33.4% heterozygotes ([TA] (6)/ [TA](7)), 14.8% mutant homozygotes ([TA](7)/[TA](7)) and a single hete rozygote with a TA deletion ([TA](5)/[TA](6)). No statistically significant difference was found between this genotype distribution and that observed in the control group (chi (2) =1.585; p > 0.05). There was also no signific ant difference in genotype distribution between neonates with physiological and non-physiological hyperbilirubinemia (chi (2) = 3.156; p > 0.05), neit her were peak jaundice levels significantly different among the various gen otypic groups (chi (2) = 1.469; p > 0.05) except in the jaundiced populatio n with associated risk factors. Our results indicate that the TATA box polymorphism did not seem to be a ma jor contributing factor to the development of neonatal hyperbilirubinemia i n our population but, when associated with other risk factors, seemed to in fluence the peak jaundice levels.