Institute of Ophthalmology, II Eye Clinic, University of Florence, Italy.
There are two distinct forms of multiple carboxylase deficiency. A neonatal onset form is due to deficiency of holocarboxylase-synthetase. A later onset form in which neurological abnormalities are seen as well as those of the skin and hair is due to biotinidase deficiency. It is the purpose of this report to describe a patient with biotinidase deficiency who presents bilateral optic atrophy. The dosage of biotinidase enzyme in the patient's serum and in other members of his family confirms the autosomal recessive transmission of this condition.