Congenital myasthenic syndromes and myasthenia

CMS diagnosis often remains difficult, due to: 1) age at onset: (a) in neonates, congenital myopathy (CM) is suspected first; (b) if age at onset is> 2 years, seronegative autoimmune MG is hypothesized; 2) clinical expression differing from a common myasthenic syndrome, with atypical features such as (a) atrophy, scoliosis, contractures, prominent permanent muscle weakness overshadowing motor fluctuations, and myogenic pattern shown by electrophysiology (eg: DOK7), (b) unresponsiveness to/negative effect of AChE inhibitors (e.g.: COLQ); (c) atypical phenotypes initially orientating towards other neuromuscular diseases: LGMD (GMPPB), distal myopathy (AGRN), Charcot Marie Tooth (SYT2); (d) histopathological pattern in favor a congenital or a metabolic myopathy; (e) ``hybrid'' entities, combining CM features (histopathology and CM gene, e.g.: centronuclear myopathy, DYN2 gene) and CMS characteristics (fatigability and decrement).

Source: Neuromuscular Disorders - September 6, 2018 Category: Neurology Authors: B. Eymard, D. Sternberg, M. Mayer, T. Stojkovic, E. Fournier, S. Nicole, A. Behin, P. Lafor êt, L. Servais, S. Bauché, B. Fontaine, D. Hantaï, M. Fardeau, N. Romero Source Type: research