Biotinidase deficiency - Diagnosis by enzyme assay and a follow-up study

A 3 month old male child was brought to the hospital with complaints of skin rashes, developmental delay, seizures, seborrheic dermatitis, alopecia and mild acidosis. The child was subjected to a simple metabolic screening protocol. The result of the screening and the clinical symptoms provided an index pointing towards biotinidase deficiency, a rare autosomal recessive, inherited metabolic disorder. The enzyme was then assayed by using n-biotinyl paminobenzoate as substrate and the diagnosis confirmed. A follow-up of the case indicated the efficacy of biotin supplementation in biotinidase deficiency.