Adult-onset Biotinidase Deficiency with Partial Remission Misdiagnosed as NMO (P4-2.010)

Biotinidase deficiency (BD) is an autosomal recessive metabolic disorder that can present atypically in adulthood and mimic demyelinating disorders. We present a case of adult-onset BD with a relapsing course initially diagnosed as neuromyelitis optica spectrum disorder (NMOSD) and treated with immunosuppressive therapy for over a decade.