congenital myasthenic syndrome 18
Findings
No curated finding names congenital myasthenic syndrome 18 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Any congenital myasthenic syndrome in which the cause of the disease is a mutation in the SNAP25 gene.
Definition from the Mondo Disease Ontology (MONDO:0014590), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance
- Onset and course
- Third trimester onset
HPO, annotations 2026-09-02
Features
13 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.
- AreflexiaHPOHP:0001284
- 1 of 1 reported patient
- AtaxiaHPOHP:0001251
- 1 of 1 reported patient
- Decreased fetal movementHPOHP:0001558
- 1 of 1 reported patient
- Delayed ability to walkHPOHP:0031936
- 1 of 1 reported patient
- DysarthriaHPOHP:0001260
- 1 of 1 reported patient
- EcholaliaHPOHP:0010529
- 1 of 1 reported patient
- Fatigable weaknessHPOHP:0003473
Show the remaining 1
- PtosisHPOHP:0000508
- 1 of 1 reported patient
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.
- SNAP25HGNC:11132
- Definitive · G2P · Autosomal dominant · 2025
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2019
- Limited · PanelApp Australia · Autosomal dominant · 2025
Where it sits
Other names
9 names
Resolves to: congenital myasthenic syndrome 18
- Also called
- CMS18congenital myasthenic syndrome caused by mutation in SNAP25congenital myasthenic syndrome type 18myasthenic syndrome, congenital, 18myasthenic syndrome, congenital, 18, with intellectual disability and ataxiamyasthenic syndrome, congenital, type 18SNAP25 congenital myasthenic syndromeSNAP25 Developmental and Epileptic Encephalopathy (SNAP25-DEE)SNAP25-DEE