For preparing this review, we (both authors) have used our personal historical literature database of publications regarding CLCN1 and SCN4A related myotonia, as well as PubMed searches using the keywords “myotonia AND (CLCN1/CLC-1, SCN4A/Nav1.4, apnea, laryngospasm).” The gene discussed is SCN4A; the disease is Laryngospasm.