A Case Report of Myoclonus-Dystonia with Isolated Myoclonus Phenotype and Novel Mutation Successfully Treated with Deep Brain Stimulation.

Introduction: Myoclonus-dystonia is an inherited disorder characterized by a combination of myoclonic jerks and dystonia. Mutations in the epsilon-sarcoglycan gene (SGCE) represent the main known genetic cause. In the last few years, deep brain stimulation (DBS) has shown significant promise in treating these patients.

Large deletions account for an increasing number of mutations in SGCE.

Myoclonus-dystonia (M-D) (MIM 159900) is a rare "dystonia plus" syndrome, characterized by rapid myoclonic jerks, predominantly in the neck and upper limbs, in combination with dystonia. Mutations in the gene epsilon-sarcoglycan (SGCE) are known to be responsible for approximately one-third of cases. We screened 21 probands diagnosed with M-D for large deletions who were mutation negative as determined by PCR-direct sequencing.