Defects in the pyruvate dehydrogenase (PDH) complex are an important cause of primary lactic acidosis. It can also present as a more chronic neurodegenerative disease with extensive cerebral atrophy and structural anomalies in the brain, as Leigh syndrome. The great majority of PDH complex deficiencies result from mutations in the X-linked pyruvate dehydrogenase (E1) alpha subunit gene.
