[Huntington disease. Current state of research]

Huntington's disease is a hereditary disease with autosomal dominant transmission which generally occurs in adults. The gene was discovered in 1983 and the genetic abnormality in March 1993. The most commonly recognized clinical manifestation is choreiform movements although other signs often appear more invalidating to family and friends. Cognitive decline, modifications in behaviour, and sometimes psychiatric disturbances are perceived as the major handicap in everyday life. In this review, emphasis has been placed on late onset forms of the disease. Recent research has focused on morphologic and functional imagery, the neuropathologic stages of selective neurone loss beginning in the striatum, and the role of excitotoxic amino-acids. Certain ethical considerations must be addressed when determining prognosis. Predictive tests and follow-up must be prepared and conducted scrupulously and proposed to voluntary, informed, major subjects at risk. Tests should be performed by a qualified laboratory working on anonymous samples, independent of the clinical team, and should be given to the subject orally by a genetic counsellor. A prenatal test may be requested by parents at risk. The question of treatment, which to date can only offer symptomatic relief, should be re-addressed in light of the recent discovery of the mutation published in March 1993.