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Mitochondrial complex I deficiency

Other Names for this Disease
  • Complex 1 mitochondrial respiratory chain deficiency
  • Mitochondrial NADH dehydrogenase component of complex I, deficiency of
  • NADH coenzyme Q reductase deficiency
  • NADH:Q(1) Oxidoreductase deficiency
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Mitochondrial complex I deficiency is a type of mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. Complex I is the first step in a chain reaction in mitochondria leading to energy production. Signs and symptoms of complex I deficiency vary widely in nature and severity, ranging from lethal neonatal disease to adult-onset neurodegenerative disorders. Features may include macrocephaly (large head) with progressive leukodystrophy, encephalopathy, hypertrophic cardiomyopathy, myopathy, liver disease, Leigh syndrome, Leber hereditary optic neuropathy, and some forms of Parkinson disease. The disease is caused by mutations in any of many genes and the inheritance pattern depends on the responsible gene. Treatment is only sometimes effective and may include metabolic therapies such as riboflavin, thiamine, biotin, co-enzyme Q10, carnitine, and a ketogenic diet (a special high-fat, low-carbohydrate diet).[1][2]
Last updated: 4/18/2014


  1. Cassandra L. Kniffin. MITOCHONDRIAL COMPLEX I DEFICIENCY. OMIM. September 17, 2013; Accessed 4/18/2014.
  2. Types of Mitochondrial Disease. United Mitochondrial Disease Foundation. Accessed 4/18/2014.
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  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs.  Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Mitochondrial complex I deficiency. Click on the link to view a sample search on this topic.