RT Book, Section A1 Bissonnette, Bruno A1 Luginbuehl, Igor A1 Marciniak, Bruno A1 Dalens, Bernard J. SR Print(0) ID 58067187 T1 Complex IV Deficiency T2 Syndromes: Rapid Recognition and Perioperative Implications YR 2006 FD 2006 PB The McGraw-Hill Companies PP New York, NY SN 9780071354554 LK accessanesthesiology.mhmedical.com/content.aspx?aid=58067187 RD 2024/10/08 AB Complex IV deficiency, also known as cytochrome c oxidase (COX) deficiency, is a very rare inherited metabolic disorder characterized by the absence of this enzyme. Several medical conditions have been associated with the cytochrome c oxidase deficiency (see Table C-2). 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. Affected infants with the benign infantile mitochondrial myopathy present similar clinical features than infants affected with the more severe infantile form of the disease, without either cardiac (hypertrophic cardiomyopathy) or kidney dysfunction. In Leigh's Disease (Subacute Necrotizing Encephalomyelopathy), a progressive degeneration of the brain is associated with significant dysfunction of the heart, kidneys, skeletal muscles, and the liver. The COX Deficiency French-Canadian Type affects skeletal muscles, connective tissue, and the liver. As observed in Leigh's Disease, the brain can be involved in this form of COX deficiency. Renal Fanconi Syndrome can be the first manisfestation of Complex IV deficiency (intermittent lactic acidosis). Complex IV is the terminal enzyme of the respiratory chain and consists of 13 polypeptide subunits. Three of these proteins are encoded by the mitochondrial DNA and the responsible catalytic subunits that carry out the electron transport function.