Acetazolamide-responsive myotonia

General Information (adopted from Orphanet):

Synonyms, Signs: MYOTONIA CONGENITA, ATYPICAL LARYNGOSPASM, SEVERE NEONATAL EPISODIC, INCLUDED
SNEL, INCLUDED
MYOTONIA CONGENITA, ACETAZOLAMIDE-RESPONSIVE
SODIUM CHANNEL MUSCLE DISEASE
MYOTONIA FLUCTUANS
MYOTONIA PERMANENS
Painful congenital myotonia
Painful myotonia
ACZ-responsive congenital myotonia
Acetazolamide-responsive congenital myotonia
Myotonia - painful contractions
ACZ-responsive myotonia
Number of Symptoms 21
OrphanetNr: 99736
OMIM Id: 608390
ICD-10: G71.1
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Autosomal dominant
[Orphanet]
Age of onset: Childhood
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Potassium-aggravated myotonia
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

1
 (HPO:0000597) Ophthalmoparesis Occasional [Orphanet] 71 / 7739
2
 (HPO:0001276) Hypertonia Very frequent [Orphanet] 317 / 7739
3
 (HPO:0001288) Gait disturbance Occasional [Orphanet] 318 / 7739
4
 (HPO:0002015) Dysphagia Occasional [Orphanet] 301 / 7739
5
 (HPO:0000821) Hypothyroidism Occasional [Orphanet] 141 / 7739
6
 (HPO:0100749) Chest pain Frequent [Orphanet] 92 / 7739
7
 (HPO:0010307) Stridor 19 / 7739
8
 (HPO:0003394) Muscle cramps Frequent [Orphanet] 106 / 7739
9
 (HPO:0002486) Myotonia Very frequent [Orphanet] 29 / 7739
10
 (HPO:0003552) Muscle stiffness 23 / 7739
11
 (HPO:0003712) Skeletal muscle hypertrophy Occasional [Orphanet] 42 / 7739
12
 (HPO:0003326) Myalgia Very frequent [Orphanet] 143 / 7739
13
 (HPO:0003457) EMG abnormality Frequent [Orphanet] 78 / 7739
14
 (HPO:0030089) Abnormal muscle fiber protein expression Occasional [Orphanet] 64 / 7739
15
 (OMIM) Cold sensitivity has been reported 4 / 7739
16
 (OMIM) EMG in myotonia permanens shows continuous myotonic activity 4 / 7739
17
 (OMIM) Laryngospasm, neonatal 4 / 7739
18
 (OMIM) Muscle weakness usually does not occur 4 / 7739
19
 (OMIM) Serum creatine kinase may be increased 6 / 7739
20
 (OMIM) Apnea, episodic, neonatal 6 / 7739
21
 (OMIM) Myotonia, potassium-sensitive (may be responsive to acetazolamide) 4 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) In a report on the 37th ENMC Workshop, Rudel and Lehmann-Horn (1997) stated that the sodium channelopathies can be divided into 3 different forms: paramyotonia, potassium-aggravated myotonia, and periodic paralysis. Potassium-aggravated myotonia includes mild myotonia fluctuans, severe myotonia ...
Diagnosis OMIM Among 22 patients with PMC, 14 with sodium channel myotonia, and 18 myotonia patients with mutations in the CLCN1 gene (118425), Fournier et al. (2006) found that cold temperature was able to exaggerate electromyographic findings in a way ...
Clinical Description OMIM Trudell et al. (1987) reported 14 patients from a kindred with an autosomal dominant form of myotonia characterized by painful muscle stiffness that was provoked by fasting and oral potassium administration. Acetazolamide treatment was effective.

Lerche ...
Molecular genetics OMIM Lerche et al. (1993) identified a heterozygous mutations in the same codon of the SCN4A gene (G1306V; 603967.0007, G1306A; 603967.0012, and G1306E; 603967.0025) in patients with exercise and potassium-aggravated myotonia, myotonia fluctuans, and myotonia permanens, respectively. Patch-clamp recordings ...