In tandem analysis of CLCN1 and SCN4A greatly enhances mutation detection in families with non-dystrophic myotonia.

Non-dystrophic myotonias (NDMs) are caused by mutations in CLCN1 or SCN4A. The purpose of the present study was to optimize the genetic characterization of NDM in The Netherlands by analysing CLCN1 and SCN4A in tandem. All Dutch consultant neurologists and the Dutch Patient Association for Neuromuscular Diseases (Vereniging Spierziekten Nederland) were requested to refer patients with an initial diagnosis of NDM for clinical assessment and subsequent genetic analysis over a full year.