Huntington's chorea: neglected opportunities for preventive medicine.

All health professionals within a defined geographical area who had any knowledge of, or contact with, patients with Huntington's chorea or their relatives were contacted and interviewed. Genetic counselling was given no consideration at all by most of the professional workers. In no case did the neurologist making the diagnosis point out the implications for the patient's family to the appropriate general practitioners who, with one exception, remained in ignorance of the genetic risk. Serious opportunities for the prevention of Huntington's chorea are being neglected.