In 1872, when Huntington1 published his famous account of "hereditary chorea," which later led to the naming of the disease for him, he stressed three essential characteristics, namely, the hereditary nature, the tendency to insanity and suicide and the age at which the onset occurs. His emphasis on the need to live to adult age in order that symptoms of the affliction may develop led for many years to the general conviction that an onset of symptoms in the third to the fifth decade of life is almost pathognomonic of Huntington's chorea; even today many neuropsychiatric texts define the disease in these terms.
Prior to 1904 most of the published papers dealing with Huntington's chorea were concerned with clinical and pathologic descriptions of the disease. In 1916, Magnus2 described 2 cases of Huntington's chorea in a man and woman in the thirties. Thereafter, much of the literature became