Biotinidase deficiency: A treatable cause of opticospinal syndrome in young adults✰

Abstract

Diagnosis of biotinidase deficiency is rare and usually made in infancy, through newborn screening or after presenting symptoms. We present the case of 19-year old male with progressive optic atrophy and in a second phase spinal cord syndrome unresponsive to immunosuppressive therapies. After diagnosis of profound biotinidase deficiency, oral biotin substitution was started with partial visual improvement and normalization of gait. This case highlights the possibility of late-onset biotinidase deficiency and its treatable character.

Keywords: Demyelinating disease; Metabolic disease (inherited); Optic nerve; Spinal cord; Visual loss.