UDP-glucuronosyltransferase promoter polymorphism in Iranian neonates with idiopathic hyperbilirubinemia.
To determine the association between polymorphism of UGT1A1 gene and idiopathic hyperbilirubinemia in Iranian neonates. Fifty neonates with idiopathic hyperbilirubinemia and Serum total bilirubin (STB) more that 15mg/dl and 50 neonates with idiopathic hyperbilirubinemia and Serum total bilirubin (STB) less than 15mg/dl enrolled in this study. Thymine-adenine (TA)  repeats in the promoter region of UGT1A1 gene investigated by means of  polymerase- chain reaction (PCR) DNA sequencing. Demographic characteristics did not differ significantly between groups while STB was higher in case group (17.5±1.9 vs. 10.4±1.8, p value<0.001). Among one hundred neonates evaluated in this study, TA6/6, TA6/7 and TA7/7 genotypes found in 52%, 42% and 6%, totally. TA6/7 and TA7/7 genotypes observed in case group more than the control group (P<0.001). STB levels were significantly higher in cases with TA6/7 and TA7/7 genotype pattern (P<0.001). Heterozygous and variant homozygous genotypes of the promoter region of UGT1A1 gene in healthy Iranian neonates with idiopathic hyperbilirubinemia should be considered.