SCO2 mutations should be screened in suspected SMA cases with normal smn mutation analysis and any one of; cardiomyopathy, lactic acidosis, or COX deficiency in muscle.
Mutations in a mitochondrial copper-binding protein (SCO2) gene were found in nine children with encephalomyopathy and/or cardiomyopathy; all of them were homozygotes or heterozygotes for 1541G>A mutation.
Mutations in a mitochondrial copper-binding protein (SCO2) gene were found in nine children with encephalomyopathy and/or cardiomyopathy; all of them were homozygotes or heterozygotes for 1541G>A mutation.
Infants with deficiency of cytochrome c oxidase (COX) due to SCO2 mutations observed so far usually demonstrated early cardiomyopathy, encephalopathy and lactic acidosis.
However, atypical clinical features were present in some patients, including normal liver function and Leigh syndrome (subacute necrotizing encephalomyelopathy) seen in association with TRMU mutations and no cardiomyopathy with founder SCO2 mutations.
One of the most frequent OXPHOS defects in humans frequently associated with cardiomyopathy is cytochrome c oxidase (COX) deficiency caused by mutations in COX assembly factors such as Sco1 and Sco2.