Screening for G71R mutation of the UDP-glucuronosyltransferase 1 (UGT1A1) gene in neonates with pathologic and prolonged hyperbilirubinemia in Turkey

Abstract

Objective: Whether the G71R mutation contributes to the high incidence of neonatal indirect hyperbilirubinemia in Turkey remains unknown. In this study we screened for G71R mutation of the UGT1A1 gene in prolonged and pathological hyperbilirubinemia with unexplained etiology in newborns in Turkey.

Method: In this study, we screened the G71R mutation of the UGT1A1 gene in 70 Turkish newborn infants: 23 infants with pathologic hyperbilirubinemia, 24 infants with prolonged hyperbilirubinemia and 23 infants without pathologic and prolonged hyperbilirubinemia. Mutations were detected by non-radioactive dye terminator cycle sequencing.

Results: In these seventy infants enrolled in this study, there were 62 with G/G (88.5 %), 8 with G/R (11.5%), and none with R/R. Two (8.7%) infants in the pathologic jaundice group and 5 (20.8 %) infants in the prolonged indirect hyperbilirubinemia, one (4.3%) infant in the control group had G/R genotype. Although G/R mutation is higher in the prolonged indirect hyperbilirubinemia group, genotypic distributions among the three groups were not statistically significant. The allele frequency of the G71R mutation was found 4.3%, 10.4%, and 2.2% in the pathologic jaundice group, in the prolonged indirect hyperbilirubinemia group, and in the control group respectively. When we compared the peak serum total bilirubin concentrations of neonates according to their genotypes, the peak bilirubin concentration was higher in G/R genotype than G/G genotype.

Conclusions: G71R mutation of UGT1A1 gene is also present in Turkish population and the presence of this mutation is associated with otherwise unexplained pathological or prolonged neonatal hyperbilirubinemia in a Turkish population.