An inborn error of bile acid synthesis (3 beta-hydroxy-Delta(5)-C-27-steroid dehydrogenase deficiency) presenting as malabsorption leading to rickets

Deficiency of 3 beta-hydroxy-Delta(5)-C-27-steroid dehydrogenase (3 beta-HS DH), the enzyme that catalyses the second reaction in the principal pathway for the synthesis of bile acids, has been reported to present with prolong ed neonatal jaundice with the biopsy features of neonatal hepatitis. It has also been shown to present between the ages of 4 and 46 months with jaundi ce, hepatosplenomegaly, and steatorrhoea (a clinical picture resembling pro gressive familial intrahepatic cholestasis). This paper reports two childre n with 3 beta-HSDH deficiency who developed rickets during infancy and did not develop clinically evident Liver disease until the age of 3 years. Bile acid replacement resulted in considerable clinical and biochemical improve ment. The importance of thorough investigation of fat soluble vitamin defic iencies in infancy is emphasised.