CAG REPEAT LENGTH AND DISEASE DURATION IN MACHADO-JOSEPH-DISEASE - A NEW CLINICAL CLASSIFICATION

To evaluate the clinical characteristics of Machado-Joseph disease (MJ D) with reference to CAG repeat length and disease duration, we analyz ed neurologic findings in 108 patients from 84 families. The majority of MJD patients presented with an ataxic gait as the initial symptom. Dysarthria and nystagmus were observed from an early stage. Bulging ey es, muscle atrophy and bradykinesia developed later. Patients with a s horter CAG repeat length or later onset had more frequent involvement of proprioceptive sensory deficit. Incidence of abnormal reflexes, ton es, and proprioceptive sensation was not associated with disease durat ion, but with CAG repeat length. Based on these results, we propose a new clinical classification: type A (juvenile type), with hyperreflexi a and dystonia, but without a proprioceptive sensory deficit; type C ( adult type), with hyporeflexia and a proprioceptive sensory deficit, b ut without dystonia; and type B (intermediate type), the remaining pat ients with a mixed presentation. (C) 1997 Elsevier Science B.V.