congenital myasthenic syndrome
Findings
No curated finding names congenital myasthenic syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Congenital myasthenic syndrome (CMS) is a group of genetic disorders of impaired neuromuscular transmission at the motor endplate characterized by fatigable muscle weakness.
Definition from the Mondo Disease Ontology (MONDO:0018940), read 2026-09-29. CC BY 4.0.
Features
67 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- DysphagiaHPOHP:0002015
- Very frequent (80% to 99% of cases)
- Fatigable weaknessHPO · MondoHP:0003473
- Very frequent (80% to 99% of cases)
- Feeding difficultiesHPOHP:0011968
- Very frequent (80% to 99% of cases)
- Frontalis muscle weaknessHPOHP:0004661
- Very frequent (80% to 99% of cases)
- Intermittent episodes of respiratory insufficiency due to muscle weaknessHPOHP:0004889
- Very frequent (80% to 99% of cases)
- Neck muscle weaknessHPOHP:0000467
- Very frequent (80% to 99% of cases)
- Poor suckHPOHP:0002033
- Very frequent (80% to 99% of cases)
- Proximal muscle weaknessHPOHP:0003701
- Very frequent (80% to 99% of cases)
- PtosisHPOHP:0000508
- Very frequent (80% to 99% of cases)
- Sudden episodic apneaHPOHP:0002882
- Very frequent (80% to 99% of cases)
- Apneic episodes precipitated by illness, fatigue, stressHPOHP:0002872
- Frequent (30% to 79% of cases)
- Arthrogryposis multiplex congenitaHPOHP:0002804
- Frequent (30% to 79% of cases)
Reported absent (1)
- Anti-neuromuscular Junction acetylcholine receptor antibody positivityHPOHP:0030208
Show the remaining 55
- AtaxiaHPOHP:0001251
- Frequent (30% to 79% of cases)
- Bulbar palsyHPOHP:0001283
- Frequent (30% to 79% of cases)
- Central sleep apneaHPOHP:0010536
- Frequent (30% to 79% of cases)
- Choking episodesHPOHP:0030842
- Frequent (30% to 79% of cases)
- CyanosisHPOHP:0000961
- Frequent (30% to 79% of cases)
- Decreased fetal movementHPOHP:0001558
- Frequent (30% to 79% of cases)
Genes
7 genes
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- CHRNEHGNC:1966
- Definitive · Illumina · Autosomal recessive · 2018
- GMPPBHGNC:22932
- Strong · Genomics England PanelApp · Autosomal recessive · 2021
- PLECHGNC:9069
- Strong · Genomics England PanelApp · Autosomal recessive · 2021
- UNC50HGNC:16046
- Moderate · PanelApp Australia · Autosomal recessive · 2025
- CHD8HGNC:20153
- Limited · Ambry Genetics · Autosomal dominant · 2020
Where it sits
- Narrower terms (8)
- congenital myasthenic syndrome 15
- congenital myasthenic syndrome 5
- congenital myasthenic syndrome with tubular aggregates
- myasthenia, congenital, refractory to acetylcholinesterase inhibitors
- myasthenic syndrome, congenital, 22
- myasthenic syndrome, congenital, 7B, presynaptic, autosomal recessive
- postsynaptic congenital myasthenic syndrome
- presynaptic congenital myasthenic syndrome
Other names
3 names
Resolves to: congenital myasthenic syndrome
- Also called
- CMSCongenital Myasthenic Syndromesmyasthenic syndrome, congenital