2022 Volume 58 Issue 1 Pages 200-204
The patient was a preterm infant born at 31 weeks and 6 days, weighing 1,816 g, admitted to the NICU for general management.
Phototherapy for unconjugated hyperbilirubinemia was initiated on day 2 and discontinued on day 3, however, the bilirubin rose again repeatedly, requiring intermittent phototherapy for about 2 months.
Based on the clinical course, bilirubin UDP-glucuronosyltransferase（UGT1A1）gene mutation was suspected, and phenobarbital（PB）2 mg/kg/d was started from day 48.
Afterwards, the bilirubin level decreased and the patient was discharged on day 64（the infant was 41 weeks and 0 days old）.
UGT1A1 gene analysis revealed that the affected child was homozygous for a missense variant of G71R（Glu71Arg）. Genetic test should be considered when breast milk jaundice due to UGT1A1 gene mutation is suspected. Free bilirubin levels（unbound bilirubin: UB）can be a useful marker whether to treat the case of prolonged jaundice.
