A case report of congenital myasthenic syndrome caused by a mutation in theCHRNE genein the Iranian population

Congenital myasthenic syndrome (CMS) refers to a heterogeneous group of inherited disorders, characterized by defective transmissionat the neuromuscular junction (NMJ). Patients with CMS showed similar muscle weakness, while other clinical manifestations are mostly dependent on genetic factors. This disease,caused bydifferent DNA mutations, is genetically inherited. It is also associated with mutations of genes at NMJ, involving the acetylcholine receptor (AChR) subunits. Here, we present the case ofa five-year-old Iranian boywith CMS, undergoingtargeted sequencing of a panel of genes, associated with arthrogryposis and CMS. The patient had six affected relatives in his genetic pedigreechart. The investigations indicated a homozygous single base pair deletion at exon 12 of the CHRNE gene (chr17:4802186delC).This region was conserved across mammalian evolution and was not submitted to the 1000 Genomes Project database.Overall, the CHRNEvariant may beclassified as a significant variant in the etiology of CMS.It can besuggested thatthe Iranian CMS population carry regional pathogenic mutations, which can be detected viatargeted and whole genome sequencing.