MYASTHENIC SYNDROME, CONGENITAL, 1B, FAST-CHANNEL

General Information (adopted from Orphanet):

Synonyms, Signs: FCCMS
Number of Symptoms 38
OrphanetNr:
OMIM Id: 608930
ICD-10:
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Autosomal dominant inheritance
Autosomal recessive inheritance
[Omim]
Age of onset: Infantile onset
[Omim]

Disease classification (adopted from Orphanet):

Parent Diseases: No data available.

Symptom Information: Sort by abundance 

1
(HPO:0000347) Micrognathia 426 / 7739
2
(HPO:0000218) High palate 356 / 7739
3
(HPO:0010628) Facial palsy 146 / 7739
4
(HPO:0000467) Neck muscle weakness 29 / 7739
5
(HPO:0000597) Ophthalmoparesis 71 / 7739
6
(HPO:0000508) Ptosis 459 / 7739
7
(HPO:0000400) Macrotia 108 / 7739
8
(HPO:0003388) Easy fatigability 34 / 7739
9
(HPO:0001270) Motor delay 322 / 7739
10
(HPO:0002015) Dysphagia 301 / 7739
11
(HPO:0001260) Dysarthria 329 / 7739
12
(HPO:0003402) Decreased miniature endplate potentials 3 / 7739
13
(HPO:0002804) Arthrogryposis multiplex congenita 93 / 7739
14
(HPO:0002650) Scoliosis 705 / 7739
15
(HPO:0002033) Poor suck 37 / 7739
16
(HPO:0001612) Weak cry 17 / 7739
17
(HPO:0002747) Respiratory insufficiency due to muscle weakness 48 / 7739
18
(HPO:0003554) Type 2 muscle fiber atrophy 14 / 7739
19
(HPO:0001283) Bulbar palsy 31 / 7739
20
(HPO:0003324) Generalized muscle weakness 48 / 7739
21
(HPO:0003391) Gowers sign 37 / 7739
22
(HPO:0001252) Muscular hypotonia 990 / 7739
23
(OMIM) Muscle biopsy shows increased numbers of endplate regions 1 / 7739
24
(OMIM) EMG shows decremental compound muscle action potential (CMAP) in response to repetitive nerve stimulation 1 / 7739
25
(HPO:0003593) Infantile onset 249 / 7739
26
(OMIM) Arthrogryposis multiplex in severe cases 4 / 7739
27
(OMIM) Muscle biopsy shows preserved junctional structure 1 / 7739
28
(OMIM) Poor feeding due to muscle weakness 5 / 7739
29
(OMIM) Muscle biopsy shows preserved nerve terminals 1 / 7739
30
(HPO:0003828) Variable expressivity 130 / 7739
31
(OMIM) Muscle biopsy shows increased length of endplate regions 1 / 7739
32
(OMIM) Muscle biopsy shows type 2 fiber atrophy 6 / 7739
33
(OMIM) Muscle biopsy shows decreased numbers of AChR 1 / 7739
34
(OMIM) Hypotonia due to defect at the neuromuscular junction 1 / 7739
35
(HPO:0000007) Autosomal recessive inheritance 2538 / 7739
36
(HPO:0000006) Autosomal dominant inheritance 2518 / 7739
37
(OMIM) Absence of acetylcholine receptor (AChR) autoantibodies 8 / 7739
38
(OMIM) Shortened acetylcholine receptor (AChR)-induced ion channel opening 1 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) Congenital myasthenic syndromes are genetic disorders of the neuromuscular junction that can be classified by the site of the transmission defect: presynaptic, synaptic, and postsynaptic. FCCMS is an autosomal recessive form of postsynaptic CMS. For a discussion of ...
Clinical Description OMIM Uchitel et al. (1993) reported a 21-year-old woman with moderately severe myasthenic symptoms since birth who responded poorly to acetylcholinesterase inhibitors. No serum antibodies to the AChR were detected. Electrophysiologic studies showed very small miniature endplate potentials (MEPP) ...
Molecular genetics OMIM In 2 unrelated patients with fast-channel congenital myasthenic syndrome, 1 of whom had been reported by Uchitel et al. (1993), Ohno et al. (1996) identified compound heterozygosity for 2 mutations in the CHRNE gene: both patients had a ...