Crigler-Najjar syndrome type 2 – an atypical case

Abstract

AIMS: The authors describe a case of Crigler-Najjar syndrome type 2, an inherited disorder of bilirubin metabolism resulting from a partial deficit of the enzyme uridine- diphospho-glucuronyl transferase (UDPG-T). CASE DESCRIPTION: A female infant of Asian ethnicity was admitted with five weeks of age by persistent jaundice since birth, with maternal report of progressive worsening. Upon physical examination the patient was active, reactive, and jaundiced, with mild axial hypotonia. Complementary examination showed increase in total bilirubin (32.94 mg/dL), with direct bilirubin of 0.94 mg/dL, and molecular study revealed two heterozygous mutations in the UGT1A1 gene (c.211G>A and c.1456T>G), consistent with Crigler-Najjar syndrome type 2. She was submitted to intensive phototherapy in combination with bile acid chelator, with a partial response. After reading the results of molecular studies, phenobarbital was started, leading to normal levels of bilirubin in two weeks. CONCLUSIONS: Crigler-Najjar syndrome type 2, although phenotypically similar to type 1, has different prognosis and treatment. In this case, early neonatal presentation and very high bilirubin values not fully yielded to intensive phototherapy, initially raised the suspicion of Crigler-Najjar syndrome type 1, which is the most severe form of the syndrome. With this report, the authors wish to draw attention to a rare cause of jaundice, which did not have its typical course.