1956G>C Polymorphism of the UDP-glucuronosyltransferase Gene (UGT1A1) for Neonatal Hyperbilirubinemia in Koreans

ABSTRACT

PURPOSE: The incidence of neonatal hyperbilirubinemia is twice as high in Eastern Asians as in Caucasians. Although it has not been clearly defined, the UDP-glucuronosyltransferase gene (UGT1A1) mutation was found to be a risk factor of neonatal hyperbilirubinemia. This study is to find an association of 1956G>C polymorphism of the UGT1A1 gene, which encodes for a key enzyme of bilirubin metabolism and neonatal hyperbilirubinemia in Korean infants. METHODS: The genomic DNA was isolated from 80 Korean full term neonates whose serum bilirubin greater than 12 mg/dL with no obvious cause. The genomic DNA was also isolated from 164 Korean neonates of the control population. We studied a single nucleotide polymorphism (SNP) of 1956G>C in the untranslated region of the UGT1A1 gene by direct sequencing. RESULTS: Three of the 80 neonates with a serum bilirubin level above 12 mg/dL had homozygous mutation and 10 of the neonates with a serum bilirubin level above 12 mg/dL had heterozygous mutation. Thirteen of the 164 neonates of the control group had homozygous mutation and 16 neonates of the control group had heterozygous mutation. The allele frequency of 1956G>C polymorphism of UGT1A1 in the hyperbilirubinemia group was 10.0 percent, which was not significantly different from the allelic frequency of 12.8 percent in the control group. CONCLUSIONS: In this study, the 1956G>C polymorphism of the UGT1A1 gene was detected in the Korean neonates with neonatal hyperbilirubinemia. Our results indicated that this SNP is not associated with the prevalence of hyperbilirubinemia in Korean.