Shrestha, Anil KumarSherpa, Sangay ChultimKarki, AsmitaAgrawal, SumitPaudel, Deepak Raj2025-07-132025-07-132025https://hdl.handle.net/20.500.14572/141Anil Kumar Shrestha Kanti Childrens Hospital, Maharajgunj, Kathmandu, Nepal Sangay Chultim Sherpa Himal Hospital, Gyaneshwor, Kathmandu, Nepal Asmita Karki Hospital for Advanced Medicine and Surgery, Dhumbarahi, Kathmandu, Nepal Sumit Agrawal Kanti Children’s Hospital, Maharajgunj, Kathmandu, Nepal Deepak Raj Paudel Rapti Academy of Health Sciences, Ghorahi, Dang, NepalCrigler–Najjar Syndrome Type 2 (CNS2) is a rare autosomal recessive disorder characterized by unconjugated hyperbilirubinemia due to partial deficiency of the enzyme uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1). We present a case of a 13-month-old male admitted to Kanti Children’s Hospital with persistent jaundice since birth. Diagnostic evaluation accompanied by gene sequencing confirmed CNS2 and the patient was effectively managed with orally administered phenobarbitone. CNS2 can be distinguished from other potential causes of unconjugated hyperbilirubinemia based on bilirubin concentration and the affected patient’s response to phenobarbitone. Genetic counselling is essential for the recognition and prevention of severe hyperbilirubinemia which, in the absence of timely medical intervention, may lead to neurotoxicity. Keywords: Case report; crigler-Najjar syndrome; genetic counseling; phenobarbitone; unconjugated hyperbilirubinemia.en-USArticle