Dystonia: Myoclonus-Dystonia

Myoclonus-dystonia (M-D) is a rare autosomal dominant movement disorder that is characterized by a combination of rapid, brief muscle contractions (myoclonus) and/or sustained twisting and repetitive movements resulting in abnormal postures (dystonia). Abnormal movements most often affect neck, trunk, and upper limbs. Age of onset is usually in childhood or early adolescence. Alcohol ingestion ameliorates the condition in most cases.. Epsilon-sarcoglycan (. SGCE) is the only gene unequivocally associated with M-D. However, mutations are found in only about 30% of the screened cases, suggesting genetic heterogeneity. Reduced penetrance in carriers inheriting the mutation from their mothers is explained by maternal imprinting of. SGCE.