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

Abstract

Objective: To assess the prevalence of UGT1A1*28 and UGT1A1*60 polymorphisms of UGT1A1 gene and their association with hyperbilirubinemia.

Study design: The study was performed at a single centre - at the Department of Obstetrics of the Medical University of Gdansk in Poland. DNA was isolated from Guthrie cards of 171 infants. Only full term newborns (gestational age 38-42 weeks) were included in the study. 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 of the UGT1A1*28 (i.e. (TA)₇/(TA)₇) homozygotes. More than 80% (55/66) of the children with "wild" type UGT1A1*28 genotype (where no polymorphism was detected) (i.e. (TA)₆/(TA)₆) carried the "wild" (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: Polymorphisms of the UGT1A1 gene frequently co-exist in neonates. The presence of UGT1A1*28 polymorphism and male gender seem to predispose to neonatal hyperbilirubinemia.

Keywords: UGT1A1 gene; hyperbilirubinemia; neonates; polymorphism.