CLCN1 and Dyggve-Melchior-Clausen disease: Similarly, proband NDM15, who resulted homozygous for the W322* mutation, should have been diagnosed with Becker’s type myotonia, but instead, he was diagnosed with severe DMC [17], indicating that the W322* mutation might be another example of CLCN1 mutations associated with both phenotypes and inheritance patterns [3].