[Huntington disease: clinical and genetic study in a Spanish population].

Clinical and genetic data of 18 unrelated patients diagnosed of Huntington's disease were studied. We examined age of onset, form of presentation, years of evolution and scores on the Shoulson-Fahn function scale, the Myers disability scale and the mini-mental state examination. The 3 clinical parameters show a linear correlation with years of disease duration. The mini-mental test was most sensitive to progression and was most closely correlated (r = 0.75, p = 0.001). Molecular analysis of the IT15 gene for all 18 patients and 96 control chromosome was performed; the range of CAG repeats was 9-29 for controls and 36-69 for patients. The correlation decreased exponentially with age of onset of symptoms and number of CAG repeats.