Responsiveness to levodopa in epsilon-sarcoglycan deletions.
ABSTRACT Myoclonus-dystonia (M-D) is characterized by early-onset myoclonus and dystonia, and is often due to mutations in the epsilon-sarcoglycan gene (SCGE) at locus 7q21. The pathogenesis of M-D is poorly understood, and in a murine knockout model, dopaminergic hyperactivity has been postulated as a mechanism. We present two unrelated individuals with M-D due to SCGE deletions who displayed a robust and sustained response to levodopa (L-dopa) treatment. In contrast to using dopamine blocking agents suggested by the hyperdopaminergic knockout model, we propose that a trial of L-dopa may be considered in patients with myoclonus-dystonia.