Huntington's disease (HD) is characterized by the presence of movement disorders, cognitive decline and psychiatric disturbances. Recently, the gene responsible for HD has been found. As a result, a more direct test for HD is available. This may lead to a comprehensive approach to HD, since it is now possible to study HD patients without uncertainties in diagnosis. We carried out a clinical-genetic study on 45 patients with HD. We performed molecular analysis on 39 patients. All had an abnormal expansion of (CAG)n ranging from 41 to 90 triplets (mean 50.8 ± 11.5 S.D.). There was a strong inverse correlation between (CAG)n expansion and age at onset Gender of the affected parent influenced age at onset (p < 0.001) and number of triplets (p < 0.001). A significant impairment of akinesia (p < 0.001), chorea (p < 0.005), MMSE (p < 0.01) and Rey scores (p < 0.05) occurred across successive stages of functional disability. Hooper Visual Organization Test (HVOT) scores did not change significantly across stages, but this test was extremely useful to discriminate between patients at an early stage and controls. A significant correlation was found between functional disability and motor-cognitive decline; correlation was stronger for motor (akinesia, r = 0.77; chorea, r = 0.61) than for cognitive aspects (MMSE, r = - 0.54; Rey, r = - 0.51; HVOT, r = -0.35).
1995 Lippincott Williams & Wilkins.