Responsiveness to phenobarbital in an adult with Crigler-Najjar disease associated with neurological involvement and skin hyperextensibility

We present the case of a 23-yr-old man who had had since birth marked and sustained unconjugated nonhemolytic hyperbilirubinemia and who had had several attacks of grand mal seizures. Analysis of serum bilirubin by diazoreactive methods showed serum levels of unconjugated bilirubin as high as 445 μmol/L that were not affected by phenobarbital administration. However, analysis of serum bile pigments by high-pressure liquid chromatography demonstrated marked decrease of unconjugated bilirubin after phenobarbital treatment (from 432.4 μmol/L to 291.0 μmol/L) associated with slight increase of bilirubin monoconjugates and diconjugates (from 0.25 μmol/L to 0.42 μmol/L). Furthermore, in the past few years the patient had exhibited striking skin hyperextensibility and diaphragm eventration. This case confirms that alkaline methanolysis-high-pressure liquid chromatography is the most reliable method for assessment of serum fraction bilirubin levels; that clinical parameters such as neurological signs do not unequivocally discriminate between type I and II Crigler-Najjar disease and that response to phenobarbital treatment remains the main diagnostic tool.