Familial congenital myopathy with prominent decremental responses in repetitive nerve stimulation testing

Abstract

Congenital myasthenic syndromes (CMSs) are rare genetic disorders characterized by weakness and fatigue resulting from impaired neuromuscular transmission. Genetic testing can confirm the diagnosis for some types of CMS; however, variations in genotype, clinical phenotypes, age at disease onset, and responses to treatment make diagnosis very difficult. Here we present two adult patients who had significant decremental responses in repetitive nerve stimulation testing and multi-minicore pathology, and who responded to treatment with a cholinesterase inhibitor.