Mitochondrial complex I deficiency
- Complex 1 mitochondrial respiratory chain deficiency
- Isolated mitochondrial respiratory chain complex I deficiency
- Isolated NADH-coenzyme Q reductase deficiency
- Isolated NADH-CoQ reductase deficiency
- Isolated NADH-ubiquinone reductase deficiency
In isolated complex I deficiency, the majority of affected people develop symptoms during the first year of life. Most people with this type have a rapidly progressive disease course and do not survive beyond childhood.
In other cases, signs and symptoms can range, causing an affected person to have any of the following:
- fatal neonatal lactic acidosis - this is typically rapidly progressive, resulting in death in infancy
- infantile-onset Leigh syndrome - affected children typically have normal early development but develop symptoms in late infancy or early childhood with progressive neurological abnormalities
- childhood-onset mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome - symptoms usually begin in childhood with seizures, migraines, vomiting, exercise intolerance, proximal limb weakness and short stature
- adult-onset syndromes of encephalomyopathy (brain and muscle disease) with variable severity
There have also been some affected people who have had involvement of only one organ (for example, isolated hypertrophic cardiomyopathy (HCM) or Leber hereditary optic neuropathy).
Because not all people with this condition are affected the same way, the life expectancy may differ considerably.
- Patrick F Chinnery. Mitochondrial Disorders Overview. GeneReviews. September 16, 2010; http://www.ncbi.nlm.nih.gov/books/NBK1224/. Accessed 4/22/2014.
- Fassone E, Rahman S. Complex I deficiency: clinical features, biochemistry and molecular genetics. J Med Genet. September, 2012; 49(9):578-590. Accessed 4/22/2014.