Neonatal hyperbilirubinemia and G71R mutation of the UGT1A1 gene in Turkish patients

Abstract

Objective. Nonphysiologic hyperbilirubinemia of unexplained cause is prevalent among Turkish newborns, suggesting that there might be genetic risk factors in this population. Mutation of the UGT1A1 gene, glycine to arginine at codon 71 (G71R), is related to the development of neonatal jaundice in East Asian populations but the frequency of this mutation is rare among Caucasian populations. There are insufficient data on the G71R mutation in Turkish newborns with hyperbilirubinemia. The aim of this study was to investigate the genotypic distribution of the G71R mutation and its relationship with nonphysiologic hyperbilirubinemia of unexplained cause in Turkish newborns.

Methods. Polymerase chain reaction, restriction fragment length polymorphism and agarose gel electrophoresis techniques were used for detection of G71R mutation in 109 newborn infants: 39 with hyperbilirubinemia and 70 without hyperbilirubinemia.

Results. The genotypic distribution for the mutation was 70 G/G, 32 A/G, 7 A/A genotypes and the mutated allele frequency was 0.22. The frequency of G71R mutation was 33.3 % (n = 13) A/G, 7.7% (n = 3) A/A in the hyperbilirubinemia group and 27.1% (n = 19) A/R, 5% (n = 4) A/A in the nonhyperbilirubinemia group. The difference between the groups was not statistically significant.

Conclusions. Our results suggest that G71R mutation of UGT1A1 is not rare; however, an association between G71R mutation and hyperbilirubinemia of unexplained cause has not been shown in Turkish newborns.

Keywords:

• Neonatal hyperbilirubinemia
• UGT1A1 gene
• G71R mutation

Acknowledgments

This study was supported by the Istanbul University Research Fund Project No: T-837/02062006.