Leigh's disease is a rare genetic neurometabolic disorder. It is characterized by the degeneration of the central nervous system (i.e., brain, spinal cord, and optic nerve). The symptoms of Leigh's disease usually begin between the ages of three months and two years. Symptoms are associated with progressive neurological deterioration and may include loss of previously acquired motor skills, loss of appetite, vomiting, irritability, and/or seizure activity. As Leigh's disease progresses, symptoms may also include generalized weakness, lack of muscle tone (hypotonia), and episodes of lactic acidosis, which may lead to impairment of respiratory and kidney function.
There appear to be several different types of genetically determined enzyme defects that can cause Leigh's disease. Most individuals with Leigh?s disease have defects of mitochondrial energy production, such as deficiency of an enzyme of the mitochondrial respiratory chain complex or the pyruvate dehydrogenase complex. In most cases, Leigh's disease is inherited as an autosomal recessive trait. However, X-linked recessive and mitochondrial inheritance have also been noted.