Mondo Description Combined oxidative phosphorylation defect type 9 is a rare mitochondrial disease due to a defect in mitochondrial protein synthesis characterized by initially normal growth and development followed by the infantile-onset of failure to thrive, psychomotor delay, poor feeding, dyspnea, severe hypertrophic cardiomyopathy and hepatomegaly. Laboratory studies report increased plasma lactate and alanine, abnormal liver enzymes and decreased activity of mitochondrial respiratory chain complexes I, III, IV, and V.

Uniprot Description A mitochondrial disease characterized by failure to thrive, poor feeding, hypertrophic cardiomyopathy, hepatomegaly, and psychomotor retardation. Death in infancy has been observed in some cases.