UGT1A1 gene variants and clinical risk factors modulate hyperbilirubinemia risk in newborns

OBJECTIVE: To study the contribution of UGT1A1 gene variants and clinical risk factors in modulating hyperbilirubinemia risk in newborns. STUDY DESIGN: Seven UGT1A1 gene variants and clinical risk factors were studied in 113 hyperbilirubinemia cases and 218 control newborns. Hyperbilirubinemia was defined as the total serum bilirubin levels >95th percentile of the American Academy of Pediatrics nomogram. The study population included term (37 to 41 weeks) newborns below 2 weeks of age. RESULT: UGT1A1 gene variants, namely, c.211G>A, g.=3279T>G, TATA box polymorphism and CAT insertion were identified as independent molecular risk factors for neonatal hyperbilirubinemia, whereas c.686C>A, c.1091C>T and c.1456T>G were not detected in study cohort. Among clinical risk factors, excessive weight loss, sepsis and ABO incompatibility emerged as independent risk factors. Co-expression of UGT1A1 variants and clinical risk factors further accentuated the risk of neonatal hyperbilirubinemia. CONCLUSION: Multiple risk factors, whether genetic or clinical, are instrumental in modulating hyperbilirubinemia risk in newborns. Disordered bilirubin conjugation through interactions of UG1TA1 gene variants contributes to the clinical phenotype of neonatal hyperbilirubinemia.