A linkage study of the loci for Huntington's disease and some common polymorphic markers.

The phenotypic frequencies of 24 polymorphic blood markers in a sample of patients with Huntington's disease (HD) have been compared with those in a sample of healthy Australian volunteers in an effort to detect any associations between HD and the markers concerned. The Rh factor, c, has a significantly lower frequency in the HD sample while ACP1c and Gm1,2 have a significantly higher frequency. The linkage relations of the HD locus have been analysed with respect to the various marker loci concerned. This analysis involved the development of methods to overcome the general lack of genetic data concerning the affected parent and the possibility that presently unaffected offspring may be asymptomatic carriers of the HD gene. The results suggest that close linkage between the HD locus and Fy, ADA, ACP1, Gc or Bg is highly unlikely. They also suggest a low probability of close linkage to ABO, Rh, Jk, Lu, AK1, PGM1 or C3. Positive linkage scores were obtained for P, Hp and Gm. The results are inconclusive for MNSs, K, Le, Se, GPT and Inv. The available data were uninformative for linkage between the HD locus and Co, 6-PGD or E1.