[Genetic analysis of a child affected with Crigler-Najjar syndrome type II].

OBJECTIVE: To detect potential mutation of the UGT1A1 gene in a child affected with Crigler-Najjar syndrome type II.

METHODS: Blood samples were collected from the patient and his parents for the extraction of genomic DNA. Potential mutation of the UGT1A1 gene was detected with polymerase chain reaction (PCR) and direct sequencing. The child was followed up until the age of 3 years and 6 months.

RESULTS: The patient showed persistent unconjugated hyperbilirubinemia. Sequencing of the UGT1A1 gene has detected a rare heterozygous c.610 A>G (p.Met204Val) mutation in the exon 1, in addition with a heterozygous c.1091 C>T (p.Pro364Leu) mutation in exon 4. The two mutations were inherited from his father and mother, respectively. The patient was diagnosed with Crigler-Najjar syndrome type II and received oral phenobarbital treatment.

CONCLUSION: The compound UGT1A1 gene mutation probably accounts for the disease in the patient manifesting persistent mild unconjugated hyperbilirubinemia. Genetic counseling and prenatal diagnosis should be provided for his family.