Mondo Description Any congenital myasthenic syndrome in which the cause of the disease is a mutation in the SNAP25 gene.

Uniprot Description A form of congenital myasthenic syndrome, a group of disorders characterized by failure of neuromuscular transmission, including pre-synaptic, synaptic, and post-synaptic disorders that are not of autoimmune origin. Clinical features are easy fatigability and muscle weakness affecting the axial and limb muscles (with hypotonia in early-onset forms), the ocular muscles (leading to ptosis and ophthalmoplegia), and the facial and bulbar musculature (affecting sucking and swallowing, and leading to dysphonia). The symptoms fluctuate and worsen with physical effort. CMS18 is an autosomal dominant presynaptic disorder clinically characterized by early-onset muscle weakness and easy fatigability associated with delayed psychomotor development and ataxia.