samples from patients with Huntington's chorea

An analysis of deoxyribonucleic acid (DNA) in deep frozen brain samples taken from 100 patients with Huntington's chorea after death showed undegraded DNA in 44 cases. Of these, 16 were analysed with G8, a recombinant DNA probe, linked to the Huntington's chorea locus. In all cases unambiguous Southern blots were obtainable. No correlation between the yield of DNA and the principal storage factors was observed. The use of stored brain tissue obtained after death from patients with Huntington's chorea should be considered when analysis of DNA is needed for predictive studies, but DNA should preferably be isolated from the tissue before storage as degradation in these samples can occur.