RT Book, Section A1 Bissonnette, Bruno A1 Luginbuehl, Igor A1 Engelhardt, Thomas SR Print(0) ID 1164066369 T1 Complex IV Deficiency T2 Syndromes: Rapid Recognition and Perioperative Implications, 2e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781259861789 LK accesspediatrics.mhmedical.com/content.aspx?aid=1164066369 RD 2024/03/29 AB Complex IV deficiency is caused by Cytochrome-c Oxidase (COX) deficiency, which is associated with several medical conditions (see Table C-1). The clinical features vary according to the type of skeletal muscles affected by the COX deficiency. Two major forms exist and are determined by the organ involvement: encephalopathic or myopathic type. Affected infants with benign infantile mitochondrial myopathy present similar clinical features as infants affected with the more severe infantile form of the disease, but lack cardiac (hypertrophic cardiomyopathy) or kidney dysfunction. In ☞Leigh’s Disease (Subacute Necrotizing Encephalomyelopathy), the progressive degeneration of the brain is associated with significant dysfunction of heart, kidneys, liver, and skeletal muscles. The French-Canadian Type of COX Deficiency affects skeletal muscles, connective tissue, and liver. Brain involvement can be similar to Leigh’s Disease. Renal Fanconi Syndrome with intermittent lactic acidosis can be the first manifestation of Complex IV deficiency. Complex IV is the terminal enzyme of the respiratory chain and consists of 13 polypeptide subunits.