1828G > A polymorphism of the UDP-glucuronosyltransferase gene (UGT1A1) for neonatal hyperbilirubinemia in Koreans / 소아과

PURPOSE: The incidence of neonatal hyperbilirubinemia is twice as high in East Asians as in Caucasians. However, its metabolic basis has not been clearly explained. The UDP-glucuronosyltransferase gene(UGT1A1) mutation was found to be a risk factor of neonatal hyperbilirubinemia. We studied whether neonatal hyperbilirubinemia is associated with the 1828G>A(rs 10929303) polymorphism of the UGT1A1 gene, which encodes for a key enzyme of bilirubin metabolism. METHODS: The genomic DNA was isolated from 80 Korean full term neonates who had greater than a 12 mg/dL level of serum bilirubin with no obvious cause, and the genomic DNA was also isolated from 164 Korean neonates of the control population. We studied a single nucleotide polymorphism (SNP) of 1828G>A 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 mutations and 10 of the 80 neonates with a serum bilirubin level above 12 mg/dL had heterozygous mutations. Thirteen of the 164 neonates of the control group had homozygous mutations and 16 neonates of the control group had heterozygous mutations. The allele frequency of 1828G>A polymorphism of UGT1A1 in the hyperbilirubinemia group was 10.0 percent, which was not significantly different from the allele frequency of 12.8 percent in the control group. CONCLUSION: In this study, the 1828G>A 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 Koreans.

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

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.

Polymorphism of UDP-glucuronosyltransferase Gene(UGT1A1) of Neonatal Hyperbilirubinemia in Korea / 소아과

PURPOSE: The incidence of neonatal hyperbilirubinemia is twice as high in East Asians as in whites and its metabolic basis has not been clearly explained. Recently, UDP-glucuronosyltransferase gene (UGT1A1) mutation was found to be a risk factor of neonatal hyperbilirubinemia in Japanese and Taiwanese Chinese. We studied whether neonatal hyperbilirubinemia is associated with mutation of UGT1A1, which is a key enzyme of bilirubin catabolism, in Korean. METHODS: The genomic DNA was isolated from 45 Korean full term neonates who had hyperbilirubinemia(serum bilirubin >12 mg/dL) with no obvious causes, and the 64 Korean neonates of the control population. We detected a missense mutation of Gly71Arg of UGT1A1 gene by using allele-specific polymerase chain reaction. Polymorphism was confirmed by direct sequencing. RESULTS: Two of the 45 neonates with serum bilirubin above 12 mg/dL had homozygous mutation and 16 neonates had heterozygous mutation. Two of the 31 neonates with serum bilirubin above 15 mg/dL had homozygous mutation and 13 neonates had heterozygous mutation. Thirteen of the control group had heterozygous mutation and homozygous mutation was not found. Allele frequency of Gly71Arg mutation in hyperbilirubinemia group was 0.22, which was significantly higher than 0.11 in the control group(P<0.0144). CONCLUSION: The missense mutation causing Gly71Arg of UGT1A1 was detected in the Korean neonatal hyperbilirubinemia. The high frequency of this missense mutation may be attributed to the high prevalence of hyperbilirubinemia in the Korean.