myasthenic syndrome, congenital, 1B, fast-channel
Findings
No curated finding names myasthenic syndrome, congenital, 1B, fast-channel yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A congenital myasthenic syndrome characterized by defects in postsynaptic neuromuscular junctions with early-onset progressive muscle weakness that has material basis in mutation in the CHRNA1 gene on chromosome 2q.
Definition from the Mondo Disease Ontology (MONDO:0012156), read 2026-09-29. CC BY 4.0.
- Onset and course
- Congenital onset
HPO, annotations 2026-09-02
Features
6 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.
- Easy fatigabilityHPOHP:0003388
- 2 of 2 reported patients
- EMG: decremental response of compound muscle action potential to repetitive nerve stimulationHPOHP:0003403
- 2 of 2 reported patients
- Limb muscle weaknessHPOHP:0003690
- 2 of 2 reported patients
- Neck muscle weaknessHPOHP:0000467
- 2 of 2 reported patients
- Weakness of facial musculatureHPOHP:0030319
- 2 of 2 reported patients
- Anti-neuromuscular Junction acetylcholine receptor antibody positivityHPOHP:0030208
- 0 of 2 reported patients
Genes
1 gene
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.
- CHRNA1HGNC:1955
- Definitive · ClinGen · Autosomal recessive · 2024
- Strong · Genomics England PanelApp · Autosomal dominant · 2021
- Strong · Genomics England PanelApp · Autosomal recessive · 2021
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2019
Where it sits
- A kind of
Other names
2 names
Resolves to: myasthenic syndrome, congenital, 1B, fast-channel
- Also called
- CMS1Bcongenital myasthenic syndrome type 1B