[Crigler-Najjar's syndrome is a rare cause of perinatal hyperbilirubinaemia]

Area of Science:

• Medical Genetics
• Hepatology
• Neonatology

Background:

• Crigler-Najjar syndrome type 1 is a rare inherited disorder characterized by severe unconjugated hyperbilirubinemia due to a deficiency in bilirubin UDP-glucuronosyltransferase (UGT1A1) activity.
• This deficiency leads to a buildup of unconjugated bilirubin, which can be neurotoxic and cause severe health issues if untreated.

Observation:

• A case study of a female infant diagnosed with Crigler-Najjar syndrome type 1 at seven days old, presenting with extremely high serum unconjugated bilirubin levels (420 micromol/l).
• The patient underwent prolonged phototherapy and later a liver transplantation at 14 years of age due to persistent high bilirubin levels (250-300 micromol/l).

Findings:

• Genetic analysis revealed a mutation in a coding exon of the UGT1A1 gene, confirming the diagnosis of Crigler-Najjar syndrome type 1.
• At 22 years old, the patient showed no signs of chronic bilirubin encephalopathy, suggesting successful management through liver transplantation.
• Liver biopsy confirmed absent bilirubin UDP-glucuronosyl transferase activity.

Implications:

• This case highlights the critical role of early diagnosis and intervention, including liver transplantation, in managing Crigler-Najjar syndrome type 1.
• The study provides incidence and prevalence data for Crigler-Najjar syndrome type 1 in Denmark (approx. 2.7 × 10-6 incidence, 0.5 × 10-6 prevalence), contributing to understanding its epidemiology.
• Effective management can prevent severe neurological sequelae, improving long-term outcomes for individuals with this rare genetic disorder.