Myoclonus-dystonia: An under-recognized entity - Report of 5 cases.

Hereditary myoclonus-dystonia (DYT 11) is caused by the epsilon-sarcoglycan (SGCE) mutation. The clinical details and investigations of cases diagnosed with myoclonus-dystonia were reviewed. We describe 5 patients (3 families) with myoclonus-dystonia diagnosed at our center. Majority of the patients had the classical phenotype with few atypical features (adult-onset disease and onset in lower limbs). Four patients carried a mutant variant in the SGCE-gene. A diagnosis of myoclonus-dystonia should be considered in cognitively normal patients with early-onset myoclonus (that may occur both at rest and/or action) with or without dystonia and with or without psychiatric-disturbances.