congenital myasthenic syndrome
Hereditary neuromuscular disorder caused by genetic defects affecting neuromuscular junction structure or function from birth.
Full Definition
Congenital myasthenic syndromes (CMS) are a heterogeneous group of inherited disorders affecting the neuromuscular junction, caused by mutations in genes encoding proteins essential for neuromuscular transmission. Unlike autoimmune myasthenia gravis, CMS symptoms typically begin in infancy or early childhood and result from structural or functional defects rather than autoimmune attack. Clinical presentation varies widely depending on the specific genetic defect but commonly includes muscle weakness, fatigability, and respiratory difficulties. Diagnosis requires clinical suspicion, electrophysiological testing, genetic analysis, and sometimes specialized studies of neuromuscular junction morphology. Treatment approaches differ from autoimmune myasthenia and depend on the specific molecular defect identified.
Usage
Usage note: CMS abbreviation acceptable; distinguish clearly from autoimmune myasthenia gravis in documentation.
In Context
- "Genetic testing identified a CHAT gene mutation causing congenital myasthenic syndrome." — Molecular diagnosis report
- "The infant's congenital myasthenic syndrome required ventilatory support and specialized feeding protocols." — Pediatric case management