[Huntington's chorea. The Liège experience]

The hereditary choreas are studied in Liège since twenty-five years. The records of psychiatric hospitals (ruled by the belgian law on confinement, 1850-1873), the archives of the "Etat-Civil" (since 1806) and the parochial registers (XVIIIth century) were tapped. From hundreds of choreic records, unquestionable or dubious, genealogical trees, sometimes stretching along nine generations were built up. About fifty pedigrees gather the patients of four Belgian provinces (out of nine). The oldest and undeniable document was written in 1793. With this wealth in hand, we are able to corroborate or invalidate diagnosis of Huntington's chorea put forward by today psychiatrists and neurologists. The diagnostic blunders were not uncommon and, sometimes, funny. The geneticist comes often too late, post mortem, through archives. When he intervenes in due time, his advice is usually not successful with young adults, uninstructed and in love. The frequency of the disease is estimated around 1 in 10.000 births. The disappearance of old pedigrees and the dawn of new ones can be predicted. Our followers will observe it and, perhaps, be able to measure the frequency of mutation.