Genetics of Huntington Disease (HD), HD-Like Disorders, and Other Choreiform Disorders

Chorea is the term used for involuntary movements that rapidly flit from region to region in an irregular pattern. In most of the conditions discussed here, the whole body is affected. There are a number of well-characterized genetic disorders that typically cause this sign, and others in which it may occur less often. In general, chorea is caused by neurodegenerative processes affecting the putamen. Prior to the identification of the gene causing Huntington disease (HD), a number of similar, apparently genetic, conditions were termed "HD-like" disorders. These diseases are discussed here, in addition to other paroxysmal choreas, neuroacanthocytosis syndromes, benign hereditary chorea, and other genetic disorders that primarily cause chorea.