Biotinidase deficiency: A novel vitamin recycling defect

Abstract
The recent finding that biotinidase deficiency is the primary biochemical defect in late-onset multiple carboxylase deficiency has stimulated new interest in the inherited disorders of biotin-dependent carboxylases. The clinical and biochemical features of biotinidase deficiency are discussed. We also speculate about two exciting areas currently being investigated: the localization of action of biotinidase, and the possible role of the enzyme as a binding or carrier protein for biotin.