CHR17 encodes the epsilon subunit of the nicotinic acetylcholine receptor, a critical component of neuromuscular transmission at the neuromuscular junction. This subunit is essential for acetylcholine receptor function, where acetylcholine binding triggers conformational changes leading to ion channel opening and membrane depolarization 1. CHR17 is one of the most commonly mutated genes in congenital myasthenic syndromes (CMS), accounting for 23.8-39.4% of CMS cases in different populations 23. Pathogenic variants in CHR17 cause three distinct CMS subtypes: slow-channel syndrome, fast-channel syndrome, and acetylcholine receptor deficiency syndrome, all characterized by impaired neuromuscular transmission leading to muscle weakness and fatigability 14. Patients with CHR17 mutations typically present with ocular symptoms and have a generally favorable long-term prognosis, with most not requiring ventilation or wheelchair assistance in adulthood 2. Treatment with β2-adrenergic receptor agonists shows the best therapeutic response for CHR17-related CMS, particularly in patients with primary acetylcholine receptor deficiency 5. The gene has also been identified as a risk variant near Alzheimer's disease loci, though its role in neurodegeneration requires further investigation 6.