Abstract
Cytochrome c oxidase (COX) is the terminal enzyme of the respiratory chain. COX deficiency is the most common mitochondrial disease in childhood.
We present results of the clinical, biochemical and molecular analyses in 106 children. Isolated COX deficiency was found in 51 children and COX deficiency combined with decreased activity another respiratory chain complex in 55 children.
Failure to thrive was observed in 64% of children, encephalopathy in 90%, hypotonia in 72%, Leigh syndrome in 20% and cardiomyopathy in 23%. Increased levels of lactate and alanine were found in blood and CSF. 72% of children died in early childhood.
Mutations c.845_846delCT in SURF1 and g.1541G>A in SCO2 gene were prevalent. Mitochondrial disorders represent a heterogeneous group of diseases.
Owing to their incidence, absence of therapy and serious social-economical consequences, elucidation of the mechanisms of mitochondrial dysfunction is essential for diagnostics, prevention and future therapeutic protocols.