Next-generation sequencing has greatly facilitated mutation detection within these genes and led to the a broadening of the phenotypic spectrum for CMS due to either AGRN [22,23] or MUSK mutations including variants in MUSK giving rise to a late onset limb girdle CMS [24▪] isolated vocal cord paralysis [25] or pregnancy-associated respiratory failure [26]. Here, MUSK is linked to congenital myasthenic syndrome.