Analysis of the epsilon-sarcoglycan gene in familial and sporadic myoclonus-dystonia: evidence for genetic heterogeneity.

The ϵ-sarcoglycan gene (SGCE) on human chromosome 7q21 has been reported to be a major locus for inherited myoclonus–dystonia. Linkage to the SGCE locus has been detected in the majority of families tested, and mutations in the coding region have been found recently in families with autosomal dominant myoclonus–dystonia. To evaluate the relevance of SGCE in myoclonus–dystonia, we sequenced the entire coding region of the ϵ-sarcoglycan gene in 16 patients with either sporadic or familial myoclonus–dystonia. No mutations were found. This study suggests that ϵ-sarcoglycan does not play an important role in sporadic myoclonus–dystonia and supports genetic heterogeneity in familial cases. © 2003 Movement Disorder Society