A case report of congenital myasthenic syndrome caused by a mutation in the CHRNE gene in the Iranian population

Congenital myasthenic syndrome (CMS) refers to a heterogeneous group of inherited disorders, characterized by defective transmission at the neuromuscular junction (NMJ). Patients with CMS showed similar muscle weakness, while other clinical manifestations are mostly dependent on genetic factors. This disease, caused by different 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 of a five-year-old Iranian boy with CMS, undergoing targeted sequencing of a panel of genes, associated with arthrogryposis and CMS. The patient had six affected relatives in his genetic pedigree chart. 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 CHRNE variant may be classified as a significant variant in the etiology of CMS. It can be suggested that the Iranian CMS population carry regional pathogenic mutations, which can be detected via targeted and whole genome sequencing.