Fast channel congenital myesthenic syndrome: Reporting two cases with mutation of CHRNE gene and short review

Abstract

Abstract Congenital myasthenic syndromes (CMSs) are hereditary neuromuscular disorders. Fast channel CMSs are a rare entity characterized by onset at birth or early infancy, easy fatigability, ptosis, proximal muscle weakness, ophthalmoplegia, etc. A positive family history may be present. Genetic mutation related to fast channel CMSs is diverse; there is variability of phenotype with genotype. CHRNE is the most common gene associated with this disorder in which post-synaptic acetylcholine receptor (AChR) is affected. Diagnosis is done by repetitive nerve stimulation (RNS) test and genetic test by excluding autoimmune cause. Most of the cases are responsive to pyridostigmine. Here we report two cases—siblings and male—with early onset of disease with typical clinical feature. The RNS test was positive, and AChR autoantibody was negative. The final diagnosis was made by next generation sequencing in which both the cases had pathogenic mutation of the CHRNE gene.