DNA Markers in Huntington’s Disease

Abstract

Huntington’s disease (HD) is an autosomal dominant human disease that represents a truly fascinating biological problem (1–4). Individuals bearing the HD gene display normal central nervous system development as far as can be determined with currently available technology. Initially they are biochemically, neurologically and behaviorally indistinguishable from non-gene carriers. The gene is fully penetrant, however, and eventually, the HD victim begins to show signs of the disorder. This usually occurs in middle age but can be as early as two years in the rarer juvenile cases. The most striking feature of HD is the movement disorder that starts subtly as clumsiness or awkwardness of gait and inevitably progresses to exaggerated involuntary “dance like” (choreiform) movements or extreme rigidity. The disease was originally termed Huntington’s chorea subsequent to its description in 1872 by George Huntington, a Long Island physician (1). The name was later changed to Huntington’s disease when it was appreciated that psychological and intellectual changes are also commonly seen and sometimes precede the onset of the movement disorder.