Association between uridin diphosphate glucuronosylotranserase 1A1 ( UGT1A1 ) gene polymorphism and neonatal hyperbilirubinemia

OBJECTIVE: To assess the prevalence of UGT1A1*28 and UGT1A1*60 polymorphisms of UGT1A1 gene and their association with hyperbilirubinemia. STUDY DESIGN: DNA was isolated from Guthrie cards of 171 infants. Fluorescent molecular probes were used for UGT1A1 promoter variation analysis. The presence of UGT1A1*28 polymorphism was detected with a dual-probe system, and UGT1A1*60 with a SimpleProbe™. RESULT: Homozygous UGT1A1*28 and UGT1A1*60 genotypes were detected in 14.6% and 20.5% of the newborns, respectively. Homozygous (G/G) genotypes of UGT1A1*60 polymorphism were found in all the UGT1A1*28 (i.e. (TA) 7 /(TA) 7 ) homozygotes. More than 80% (55/66) of the children with normal (i.e. (TA) 6 /(TA) 6 ) of UGT1A1*28 genotype carried the normal (T/T) genotype of UGT1A1*60 as well. The UGT1A1*28 polymorphism was detected more often among neonates with elevated bilirubin. Hyperbilirubinemia was diagnosed more frequently in boys. CONCLUSION: The polymorphisms of UGT1A1 gene frequently co-exist in neonates. The presence of UGT1A1*28 polymorphism and male gender seem to predispose to neonatal hyperbilirubinemia.