Analyses of polymorphism for UGT1*1 exon 1 promoter in neonates with pathologic and prolonged jaundice.

In this study, we investigated whether a TATA box polymorphism in the promoter of the UGT1*1 exon I, the most common detected DNA polymorphism in Gilbert's syndrome, is a contributory factor in unexplained pathologic or prolonged jaundice. 38 neonates who had unexplained pathologic jaundice, 37 neonates who had unexplained prolonged jaundice, and 35 healthy, nonjaundiced neonates were enrolled in the study. Genotypes were assigned as follows: 6/6 (homozygous for a normal allele bearing the sequence [TA](6)TAA), 7/7 (homozygous for an abnormal allele with the sequence [TA](7)TAA), and 6/7 (heterozygous with one of each allele). Of the 110 infants, 10 (9%) had 7/7, 51 (46%) had 6/7, and 49 (45%) had 6/6 genotype; the differences between the three groups were not statistically significant. Also no differences were observed among different genotypes and mean serum total bilirubin concentrations. In conclusion, we showed that TA 7/7 and TA 6/7 genotypes are not rare in our population and that the presence of these polymorphisms alone does not play a significant role in the etiology of unexplained pathologic or prolonged neonatal hyperbilirubinemia.