Abstract
Leigh syndrome (or subacute necrotizing encephalomyelopathy) is a rare neurodegenerative disorder characterized by psychomotor retardation or regression, typically occurring in stepwise decrements. Onset is typically between ages 3 and 12 months. Neurological manifestations include hypotonia, spasticity, movement disorders (including chorea), cerebellar ataxia, and peripheral neuropathy, whereas extraneurological manifestations may include hypertrophic cardiomyopathy, hypertrichosis, anemia, renal tubulopathy, liver involvement, ptosis, and muscle weakness. Approximately 50% of affected individuals die by age 3 years, most often as a result of respiratory or cardiac failure. We report a case of 22-month-old female child presenting to us with severe failure to thrive, dysmorphic features, hirsutism, external ophthalmoplegia epilepsy, and neuroregression with characteristic findings of Leigh's syndrome on neuroimaging and her muscle biopsy revealed evidence of mitochondrial respiratory chain defect involving complex IV and SURF1 mutation.