DELTA(4)-3-OXOSTEROID 5-BETA-REDUCTASE DEFICIENCY - FAILURE OF URSODEOXYCHOLIC ACID TREATMENT AND RESPONSE TO CHENODEOXYCHOLIC ACID PLUS CHOLIC-ACID

Background-In some infants with liver disease, 3-oxo-Delta(4) bile aci ds are the major bile acids in urine, a phenomenon attributed to reduc ed activity of the Delta(4)-3-oxosteroid 5 beta-reductase required for synthesis of chenodeoxycholic acid and cholic acid. These patients fo rm a heterogeneous group. Many have a known cause of hepatic dysfuncti on 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 chol estasis, increased plasma concentrations of 3-oxo-Delta(4) bile acids, low plasma concentrations of chenodeoxycholic acid and cholic acid, a nd 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 chroni c cholestatic liver disease associated with malabsorption of vitamins D and E and a normal gamma-glutamyltranspeptidase when the transaminas es were increased. The liver disease failed to improve with ursodeoxyc holic acid but responded to a combination of chenodeoxycholic acid and cholic acid. Conclusion-Treatment of primary 5 beta-reductase deficie ncy requires the use of bile acids that inhibit cholesterol 7 alpha-hy droxylase.