Alpers disease: A progressive disease of the nervous system characterized by spasticity (tightness), myoclonus and dementia and by liver problems with jaundice and cirrhosis. This disorder, first described by Alpers in 1931 as "Diffuse progressive degeneration of gray matter of cerebrum", usually begins early in life with convulsions. A continuous seizure (status epilepticus) is often the final event.

Alpers disease is due to more than one cause. Some cases are inherited as autosomal recessive traits with both parents appearing normal but carrying one Alpers gene and each of their children, boys and girls alike, standing a 1 in 4 risk of receiving both of the parental Alpers genes and of suffering from this dread disease.

Other cases of Alpers disease are disorders of oxidative phosphorylation, including mitochondrial DNA depletion syndromes. (Phosphorylation is the addition of phosphate to an organic compound, such as the addition of phosphate to ADP [adenosine diphosphate] to form ATP [adenosine triphosphate] or the addition of phosphate to glucose to produce glucose monophosphate, through the action of enzymes known as phosphotransferases or kinases.)

Alpers disease is also called Alpers progressive infantile poliodystrophy, progressive infantile poliodystrophy, diffuse degeneration of cerebral gray matter with hepatic cirrhosis, and Alpers diffuse degeneration of cerebral gray matter with hepatic cirrhosis.