A novel mutation in the ε-sarcoglycan gene causing myoclonus–dystonia syndrome

Two families were referred with different clinical diagnoses of dystonia. Twenty-four family members were examined clinically, and mutation analyses were performed. Most of the affected individuals had laryngeal myoclonus and more severe dystonia of the legs than usually reported in myoclonus–dystonia syndrome. Sequence analyses revealed a previously unreported deletion (974delC or R325X) in exon 7 in the ε-sarcoglycan gene in members of both families. The two families were found to be related.