Potassium-aggravated 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
PAM
K-aggravated myotonia
K+-aggravated myotonia
Number of Symptoms 28
OrphanetNr: 612
OMIM Id: 608390
ICD-10: G71.1
UMLs: C2931826
MeSH: C538353
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: Genetic muscular channelopathy
 -Rare genetic disease
Muscular channelopathy
 -Rare neurologic disease
Myotonic syndrome
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

1
 (HPO:0000597) Ophthalmoparesis Occasional [Orphanet] 71 / 7739
2
 (HPO:0001288) Gait disturbance Frequent [Orphanet] 318 / 7739
3
 (HPO:0002015) Dysphagia Frequent [Orphanet] 301 / 7739
4
 (HPO:0001276) Hypertonia Very frequent [Orphanet] 317 / 7739
5
 (HPO:0001332) Dystonia Occasional [Orphanet] 197 / 7739
6
 (HPO:0100749) Chest pain Occasional [Orphanet] 92 / 7739
7
 (HPO:0001387) Joint stiffness Occasional [Orphanet] 322 / 7739
8
 (HPO:0003236) Elevated serum creatine phosphokinase Occasional [HPO:probinson] 214 / 7739
9
 (HPO:0002153) Hyperkalemia Occasional [Orphanet] 25 / 7739
10
 (HPO:0010307) Stridor 19 / 7739
11
 (HPO:0005949) Apneic episodes in infancy 5 / 7739
12
 (HPO:0002093) Respiratory insufficiency Occasional [Orphanet] 410 / 7739
13
 (HPO:0002486) Myotonia Very frequent [Orphanet] 29 / 7739
14
 (HPO:0003326) Myalgia Frequent [Orphanet] 143 / 7739
15
 (HPO:0003394) Muscle cramps Frequent [Orphanet] 106 / 7739
16
 (HPO:0003457) EMG abnormality Frequent [Orphanet] 78 / 7739
17
 (HPO:0003712) Skeletal muscle hypertrophy Occasional [Orphanet] 42 / 7739
18
 (HPO:0001324) Muscle weakness Occasional [Orphanet] 859 / 7739
19
 (HPO:0003552) Muscle stiffness 23 / 7739
20
 (HPO:0000006) Autosomal dominant inheritance 2518 / 7739
21
 (OMIM) Apnea, episodic, neonatal 6 / 7739
22
 (OMIM) Serum creatine kinase may be increased 6 / 7739
23
 (OMIM) EMG in myotonia permanens shows continuous myotonic activity 4 / 7739
24
 (OMIM) Myotonia, potassium-sensitive (may be responsive to acetazolamide) 4 / 7739
25
 (OMIM) Muscle weakness usually does not occur 4 / 7739
26
 (OMIM) Cold sensitivity has been reported 4 / 7739
27
 (OMIM) Laryngospasm, neonatal 4 / 7739
28
 (HPO:0030089) Abnormal muscle fiber protein expression Frequent [Orphanet] 64 / 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 ...