A causal relationship between UDP-glucuronosyltransferase 1A1 promoter polymorphism and idiopathic hyperbilirubinemia in Turkish newborns

• Published in: Turkish journal of pediatrics Vol. 52; no. 1; pp. 28 - 34
• Main Authors: Ergin, Hacer, Bican, Mevlüt, Atalay, O Erol
• Format: Journal Article
• Language: English
• Published: Turkey Hacettepe University Faculty of Medicine 01.01.2010
• Subjects: Genotype; Glucuronosyltransferase - genetics; Histocompatibility, Maternal-Fetal - genetics; Humans; Hyperbilirubinemia, Neonatal - genetics; Infant, Newborn; Polymorphism, Genetic; Promoter Regions, Genetic - genetics; Sequence Analysis, DNA
• ISSN: 0041-4301

The etiology of pathological jaundice can not be identified in almost half of the cases. The effect of promoter polymorphism in the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene was investigated in healthy breast-fed Turkish neonates with unexplained and direct Coombs'-negative ABO incompatible hyperbilirubinemia. Newborns whose peak serum bilirubin levels were > or = 17 mg/dl and < or = 12.9 mg/dl within the first week of life formed the idiopathic hyperbilirubinemia (n: 50) and control (n: 54) groups, respectively. Thymine-adenine (TA) repeats in the promoter region of the UGT1A1 gene were investigated by polymerase chain reaction (PCR)-based non-radioactive DNA sequencing. In the idiopathic hyperbilirubinemia group, higher peak bilirubin levels, higher heterozygous and variant homozygous genotypes, higher TA7 allele frequencies, and shorter peak time were observed (p < 0.001, p < 0.001, p < 0.001, p < 0.05, respectively). In conclusion, healthy breast-fed Turkish neonates who carry heterozygous and variant homozygous genotypes in the UGT1A1 gene are at high risk of developing significant hyperbilirubinemia without additional icterogenic factors.