[The preclinical DNA diagnosis of Huntington's chorea].

Presymptomatic DNA diagnosis of Huntington's chorea (HC) was made for two sons of a patient affected with the disease using amplification of the DNA fragment in the area of locus G 8 linked with HC gene. That fragment contains a polymorphous site in the area of restrictase recognition Hind III, being of information value as regards the family under examination. The familial analysis with the use of the DNA diagnosis data makes it possible to exclude the inheritance of HC gene for both the sons of the patient with a probability of 96%.