Myoclonus-dystonia syndrome: epsilon-sarcoglycan mutations and phenotype.

Mutations in the gene for epsilon-sarcoglycan (SGCE) have been found to cause myoclonus-dystonia syndrome. We now report clinical and genetic findings in nine additional European families with myoclonus-dystonia syndrome. The clinical presentation in 24 affecteds was homogeneous with myoclonus predominantly of neck and upper limbs in 23 of them and dystonia, presenting as cervical dystonia and/or writer's cramp, in 13 cases. Six novel and one previously known heterozygous SGCE mutations were identified. SGCE deficiency seems to be the common pathogenetic mechanism in myoclonus-dystonia syndrome.