The Turkish Journal of Pediatrics
2010 , Vol 52 , Num 1
A causal relationship between UDP-glucuronosyltransferase 1A1 promoter polymorphism and idiopathic hyperbilirubinemia in Turkish newborns
Departments of 1Pediatrics, and 3Biophysics, Pamukkale University Faculty of Medicine, Denizli, and 2Şanlıurfa Children's Hospital, Şanlıurfa, Turkey
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 ≥17
mg/dl and ≤12.9 mg/dl within the first week of life formed the idiopathic
hyperbilirubinemia (n: 50) and control (n: 54) groups, respectively. Thymineadenine
(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
Keywords :
hyperbilirubinemia, ABO incompatibility, promoter polymorphism, glucose-
6-phosphate dehydrogenase deficiency, Gilbert syndrome, breast-feeding.