Combined oxidative phosphorylation defect type 39

Definition

A rare mitochondrial oxidative phosphorylation disorder characterized by early onset of severe developmental delay (sometimes with regression of developmental milestones) and intellectual disability, poor or absent speech, and hypotonia. Other features include movement disorder, seizures, or microcephaly, among others. Brain imaging may show features of Leigh syndrome with signal abnormalities in the basal ganglia or mid brain, cerebellar atrophy, or thin corpus callosum.