Molecular diagnosis of Huntington's disease in Mexican patients by polymerase chain reaction.

Three highly informative markers genetically linked to Huntington's Disease (HD) were used for diagnosis of HD in Mexican patients, two polymorphic HindIII sites located at D4S10 locus and one VNTR marker at D4S111 locus (VNTR-111). Forty chromosomes from healthy subjects were tested in order to evaluate the informativeness of the probes. The RFLP HindIII 1 and 2 and the VNTR-111 probes showed a heterozygosity of 0%, 45%, and 60%, respectively. Five families were analyzed, of these, only in two the markers used were informative. In one of them, six members showed a decreased risk of inheritance of the mutant gene for Huntington's Disease with 95% accuracy (1).