Abstract

BACKGROUND--In some infants with liver disease, 3-oxo-delta 4 bile acids are the major bile acids in urine, a phenomenon attributed to reduced activity of the delta 4-3-oxosteroid 5 beta-reductase required for synthesis of chenodeoxycholic acid and cholic acid. These patients form a heterogeneous group. Many have a known cause of hepatic dysfunction and plasma concentrations of chenodeoxycholic acid and cholic acid that are actually greater than those of the 3-oxo-delta 4 bile acids. It is unlikely that these patients have a primary genetic deficiency of the 5 beta-reductase enzyme. AIMS--To document the bile acid profile, clinical phenotype, and response to treatment of an infant with cholestasis, increased plasma concentrations of 3-oxo-delta 4 bile acids, low plasma concentrations of chenodeoxycholic acid and cholic acid, and no other identifiable cause of liver disease. PATIENTS--This infant was compared with normal infants and infants with cholestasis of known cause. METHODS--Analysis of bile acids by liquid secondary ionisation mass spectrometry and gas chromatography-mass spectrometry. RESULTS--The plasma bile acid profile of the patient was unique. She had chronic cholestatic liver disease associated with malabsorption of vitamins D and E and a normal gamma-glutamyltranspeptidase when the transaminases were increased. The liver disease failed to improve with ursodeoxycholic acid but responded to a combination of chenodeoxycholic acid and cholic acid. CONCLUSION--Treatment of primary 5 beta-reductase deficiency requires the use of bile acids that inhibit cholesterol 7 alpha-hydroxylase.