Evidence of genetic heterogeneity in Huntington's chorea.

In an extensive study of Huntington's chorea in Queensland evidence was found to support an old observation that the magnitude of the variation in the symptom complex of the disease between different families is sufficient to suggest that there may be more than one form of Huntington's chorea allele present in the community. Analysis of data concerning age at onset indicates that at least two separate forms of the disorder may exist.