A boy with urso-dependent hypertransaminasemia

We present a case of a 6 year-old boy with chronic hypertransaminasemia referred to our observation at the age of 17 months, with ALT levels of 2,147 IU/L without signs of cholestasis. Main causes of hypertransaminasemia were excluded and liver biopsy showed chronic hepatitis with minimal activity and moderate portal fibrosis. Therapy with ursodeoxycholic acid (UDCA) was started with a rapid normalization of transaminases. UDCA was suspended in 3 circumstances and in all cases a rapid increase in transaminases was observed. The prompt reinstitution of UDCA was always followed by a rapid normalization of liver enzymes. A defect of bile acid synthesis or conjugation was suspected. Evaluation of urinary biliary acid pattern showed a normal profile on UDCA therapy. Although conjugated biliary acids serum levels were in the normal range, the levels were very low in absence of UDCA therapy and increased in UDCA when transaminases were normal. Therefore, a familial hypercholanemia, with associated defect of the Bile Acid CoA: amino acid N-acyltransferase (BAAT) was suspected. At present this hypothesis is under investigation. Even if the diagnosis is not still confirmed, this case suggests the disorder as possible cause of hypertransaminasemia not associated with signs of cholestasis.