Congenital myasthenic syndrome

Congenital myasthenic syndrome is an inherited neuromuscular disorder caused by defects of several types at the neuromuscular junction, distinct from autoimmune myasthenic conditions because it is not an autoimmune disorder. It is rare, affecting roughly one in 200,000 people, with only about 600 known family cases documented. The disorder stems from genetic defects affecting proteins at the neuromuscular junction, most commonly in genes encoding acetylcholine receptors and related proteins such as rapsyn, which are essential for proper transmission of muscle signals. Manifestations vary by the specific genetic type but commonly include droopy eyelids and muscle weakness. Symptoms can include brief stops in breathing, weakness of the eye, mouth and throat muscles, respiratory difficulties, feeding problems, and delayed motor development in affected infants and children.