P447: Late onset biotinidase deficiency misdiagnosed as neuromyelitis optica: A case report and review of diagnostic challenges

Treatment and Management: Patient was started on 10 mg biotin daily.Outcome and Follow-Up: Patient is currently undergoing monitoring for improvement in symptoms.Treatment with biotin may reverse many of the ophthalmologic findings and some or all of the myelopathy.Discussion: Late onset biotinidase deficiency may be mistaken for neuromyelitis optica, multiple sclerosis, or an alternative neurogenetic condition.Testing for late onset biotinidase deficiency is fast, inexpensive, and if diagnostic, would result in a significant change in management.Conclusion: Further research is needed on the incidence of late onset biotinidase deficiency in those with clinical diagnoses of neuromyelitis optica and multiple sclerosis.Introduction: Biotinidase deficiency, if not detected on newborn screening, is classically a early childhood onset disorder which may present with seizures, developmental delay, skin rash, alopecia, optic atrophy, hearing loss, and respiratory problems.However, rare instances show late onset in older children, adolescents, or adults with symptoms such as optic atrophy, peripheral neuropathy, myelopathy, spastic paraparesis, recurrent infections, and white matter abnormalities.Case Presentation: Patient is a 33-year-old male with progressive spastic diplegia, bilateral optic atrophy, peripheral neuropathy, neurogenic bladder, and recurrent infectious.White matter abnormalities were present on the MRI of brain and spine.Symptoms began in his twenties.He was previously diagnosed with Neuromyelitis Optica, but treatment was unsuccessful.Extensive workup prior to genetics evaluation was non-diagnostic.