Genetic Factors and Delayed TSB Monitoring and Treatment as Risk Factors Associated with Severe Hyperbilirubinemia in Term Neonates Admitted for Phototherapy

J Trop Pediatr. 2020 Dec 1;66(6):569-582. doi: 10.1093/tropej/fmaa016.

Abstract

Objectives: This study aimed to determine whether maternal-fetal blood group isoimmunization, breastfeeding, birth trauma, age when first total serum bilirubin (TSB) was measured, age of admission, and genetic predispositions to hemolysis [due to genetic variants of glucose-6-phosphate dehydrogenase (G6PD) enzyme], and reduced hepatic uptake and/or conjugation of serum bilirubin [due to genetic variants of solute carrier organic anion transporter protein family member 1B1 (SLCO1B1) and uridine diphosphate glucuronosyltransferase family 1 member A1 (UGT1A1)] were significant risk factors associated with severe neonatal hyperbilirubinemia (SNH, TSB ≥ 342µmol/l) in jaundiced term neonates admitted for phototherapy.

Methods: The inclusion criteria were normal term neonates (gestation ≥ 37 weeks). Parents/care-givers were interviewed to obtain data on demography, clinical problems, feeding practice and age when first TSB was measured. Polymerase chain reaction-restriction fragment length polymorphism method was used to detect common G6PD, UGT1A1 and SLCO1B1 variants on each neonate's dry blood specimens.

Results: Of 1121 jaundiced neonates recruited, 232 had SNH. Logistic regression analysis showed that age (in days) when first TSB was measured [adjusted odds ratio (aOR) = 1.395; 95% confidence interval (CI) 1.094-1.779], age (in days) of admission (aOR = 1.127; 95% CI 1.007-1.260) and genetic mutant UGT1A1 promoter A(TA)7TAA (aOR = 4.900; 95% CI 3.103-7.739), UGT1A1 c.686C>A (aOR = 6.095; 95% CI 1.549-23.985), SLCO1B1 c.388G>A (aOR = 1.807; 95% CI 1.242-2.629) and G6PD variants and/or abnormal G6PD screening test (aOR = 2.077; 95% CI 1.025-4.209) were significantly associated with SNH.

Conclusion: Genetic predisposition, and delayed measuring first TSB and commencing phototherapy increased risk of SNH.

Keywords: age when first TSB was measured; genetic predisposition; risk factors; severe neonatal hyperbilirubinemia.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amplified Fragment Length Polymorphism Analysis
  • Bilirubin / blood*
  • Case-Control Studies
  • Female
  • Genetic Predisposition to Disease
  • Glucosephosphate Dehydrogenase / genetics*
  • Glucosephosphate Dehydrogenase / metabolism
  • Glucuronosyltransferase / genetics*
  • Glucuronosyltransferase / metabolism
  • Humans
  • Hyperbilirubinemia, Neonatal / diagnosis
  • Hyperbilirubinemia, Neonatal / genetics*
  • Hyperbilirubinemia, Neonatal / therapy
  • Infant, Newborn
  • Jaundice
  • Liver / metabolism*
  • Liver-Specific Organic Anion Transporter 1 / genetics*
  • Liver-Specific Organic Anion Transporter 1 / metabolism
  • Male
  • Phototherapy

Substances

  • Liver-Specific Organic Anion Transporter 1
  • SLCO1B1 protein, human
  • Glucosephosphate Dehydrogenase
  • UGT1A1 enzyme
  • Glucuronosyltransferase
  • Bilirubin