Thomsen and Becker disease
MONDO:0009710Mondo
Findings
No curated finding names Thomsen and Becker disease yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare, genetic, skeletal muscle channelopathy characterized by slow muscle relaxation after contraction (myotonia).
Definition from the Mondo Disease Ontology (MONDO:0009710), read 2026-09-29. CC BY 4.0.
Features
15 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.
- EMG abnormalityHPOHP:0003457
- Very frequent (80% to 99% of cases)
- EMG: myotonic dischargesHPOHP:0100284
- Very frequent (80% to 99% of cases)
- Muscle stiffnessHPOHP:0003552
- Very frequent (80% to 99% of cases)
- MyotoniaHPOHP:0002486
- Very frequent (80% to 99% of cases)
- Myotonia with warm-up phenomenonHPOHP:0003740
- Very frequent (80% to 99% of cases)
- MyalgiaHPOHP:0003326
- Frequent (30% to 79% of cases)
- Skeletal muscle hypertrophyHPOHP:0003712
- Frequent (30% to 79% of cases)
- ClumsinessHPOHP:0002312
- Occasional (5% to 29% of cases)
- EMG: myopathic abnormalitiesHPOHP:0003458
- Occasional (5% to 29% of cases)
- Feeding difficulties in infancyHPOHP:0008872
- Occasional (5% to 29% of cases)
- Muscle spasmHPOHP:0003394
- Occasional (5% to 29% of cases)
- Progressive distal muscle weaknessHPOHP:0009063
- Occasional (5% to 29% of cases)
Show the remaining 3
- ArrhythmiaHPOHP:0011675
- Very rare (1% to 4% of cases)
- Cardiac conduction abnormalityHPOHP:0031546
- Very rare (1% to 4% of cases)
- DysphagiaHPOHP:0002015
- Very rare (1% to 4% of cases)
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.
- CLCN1HGNC:2019
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
- A kind of
Other names
1 name
Resolves to: Thomsen and Becker disease
- Also called
- myotonia congenita