MCID: MYS049
MIFTS: 19

Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Categories: Genetic diseases, Neuronal diseases

Aliases & Classifications for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

MalaCards integrated aliases for Myasthenic Syndrome, Congenital, 3b, Fast-Channel:

Name: Myasthenic Syndrome, Congenital, 3b, Fast-Channel 57 75 29 6
Cms3b 57 12 75
Myasthenic Syndrome, Congenital, Type 3b, Fast-Channel 40
Congenital Myasthenic Syndrome 3b, Fast-Channel 12
Congenital Myasthenic Syndrome 3b 12

Characteristics:

OMIM:

57
Inheritance:
autosomal recessive

Miscellaneous:
onset in infancy
may respond to cholinesterase inhibitors of amifampridine


HPO:

32
myasthenic syndrome, congenital, 3b, fast-channel:
Onset and clinical course infantile onset
Inheritance autosomal recessive inheritance


Classifications:



Summaries for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

UniProtKB/Swiss-Prot : 75 Myasthenic syndrome, congenital, 3B, fast-channel: A form of congenital myasthenic syndrome, a group of disorders characterized by failure of neuromuscular transmission, including pre- synaptic, synaptic, and post-synaptic disorders that are not of autoimmune origin. Clinical features are easy fatigability and muscle weakness affecting the axial and limb muscles (with hypotonia in early-onset forms), the ocular muscles (leading to ptosis and ophthalmoplegia), and the facial and bulbar musculature (affecting sucking and swallowing, and leading to dysphonia). The symptoms fluctuate and worsen with physical effort. CMS3B is a fast-channel myasthenic syndrome. It is caused by kinetic abnormalities of the AChR, resulting in brief opening and activity of the channel, with a rapid decay in endplate current, failure to achieve threshold depolarization of the endplate and consequent failure to fire an action potential.

MalaCards based summary : Myasthenic Syndrome, Congenital, 3b, Fast-Channel, is also known as cms3b. An important gene associated with Myasthenic Syndrome, Congenital, 3b, Fast-Channel is CHRND (Cholinergic Receptor Nicotinic Delta Subunit). Related phenotypes are high palate and ptosis

Disease Ontology : 12 A congenital myasthenic syndrome characterized by autosomal recessive inheritance of postsynaptic neuromuscular junction defects resulting in rapid decay in endplate current and a failure to reach the threshold for depolarization and early onset progressive muscular weakness that has material basis in homozygous or compound heterozygous mutation in the CHRND gene on chromosome 2q37.

OMIM : 57 Fast-channel congenital myasthenic syndrome (FCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor channel, specifically from abnormally brief opening and activity of the channel, with a rapid decay in endplate current and a failure to reach the threshold for depolarization. Treatment with pyridostigmine or amifampridine may be helpful; quinine, quinidine, and fluoxetine should be avoided (summary by Sine et al., 2003 and Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462). (616322)

Related Diseases for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Diseases in the Myasthenic Syndrome, Congenital, 1b, Fast-Channel family:

Myasthenic Syndrome, Congenital, 3b, Fast-Channel Myasthenic Syndrome, Congenital, 4b, Fast-Channel

Symptoms & Phenotypes for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Symptoms via clinical synopsis from OMIM:

57
Head And Neck Eyes:
ptosis
ophthalmoplegia

Respiratory:
respiratory insufficiency

Head And Neck Mouth:
high-arched palate

Abdomen Gastrointestinal:
poor feeding

Neurologic Central Nervous System:
delayed motor development due to muscle weakness

Muscle Soft Tissue:
muscle weakness
easy fatigability
hypotonia, neonatal
decremental response to repetitive nerve stimulation
decreased amplitudes of the miniature endplate potential (mepp) and current (mepc)
more
Head And Neck Neck:
neck muscle weakness

Head And Neck Face:
facial muscle weakness

Prenatal Manifestations Movement:
decreased fetal movements (in some patients)

Skeletal Hands:
hand contractures (in some patients)


Clinical features from OMIM:

616322

Human phenotypes related to Myasthenic Syndrome, Congenital, 3b, Fast-Channel:

32 (show all 10)
# Description HPO Frequency HPO Source Accession
1 high palate 32 HP:0000218
2 ptosis 32 HP:0000508
3 respiratory insufficiency 32 HP:0002093
4 facial palsy 32 HP:0010628
5 neonatal hypotonia 32 HP:0001319
6 feeding difficulties 32 HP:0011968
7 decreased fetal movement 32 occasional (7.5%) HP:0001558
8 neck muscle weakness 32 HP:0000467
9 ophthalmoplegia 32 HP:0000602
10 easy fatigability 32 HP:0003388

Drugs & Therapeutics for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Search Clinical Trials , NIH Clinical Center for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Genetic Tests for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Genetic tests related to Myasthenic Syndrome, Congenital, 3b, Fast-Channel:

# Genetic test Affiliating Genes
1 Myasthenic Syndrome, Congenital, 3b, Fast-Channel 29 CHRND

Anatomical Context for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Publications for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Variations for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

UniProtKB/Swiss-Prot genetic disease variations for Myasthenic Syndrome, Congenital, 3b, Fast-Channel:

75
# Symbol AA change Variation ID SNP ID
1 CHRND p.Glu80Lys VAR_021210 rs121909504
2 CHRND p.Pro271Gln VAR_021211 rs121909503
3 CHRND p.Leu42Pro VAR_073691
4 CHRND p.Ile79Lys VAR_073692 rs121909509

ClinVar genetic disease variations for Myasthenic Syndrome, Congenital, 3b, Fast-Channel:

6
# Gene Variation Type Significance SNP ID Assembly Location
1 CHRND NM_000751.2(CHRND): c.812C> A (p.Pro271Gln) single nucleotide variant Pathogenic rs121909503 GRCh37 Chromosome 2, 233394841: 233394841
2 CHRND NM_000751.2(CHRND): c.812C> A (p.Pro271Gln) single nucleotide variant Pathogenic rs121909503 GRCh38 Chromosome 2, 232530131: 232530131
3 CHRND NM_000751.2(CHRND): c.236T> A (p.Ile79Lys) single nucleotide variant Pathogenic rs121909509 GRCh37 Chromosome 2, 233392148: 233392148
4 CHRND NM_000751.2(CHRND): c.236T> A (p.Ile79Lys) single nucleotide variant Pathogenic rs121909509 GRCh38 Chromosome 2, 232527438: 232527438
5 CHRND NM_000751.2(CHRND): c.238G> A (p.Glu80Lys) single nucleotide variant Pathogenic rs121909504 GRCh37 Chromosome 2, 233392150: 233392150
6 CHRND NM_000751.2(CHRND): c.238G> A (p.Glu80Lys) single nucleotide variant Pathogenic rs121909504 GRCh38 Chromosome 2, 232527440: 232527440
7 CHRND NM_000751.2(CHRND): c.820_820+1del deletion Pathogenic rs879255564 GRCh38 Chromosome 2, 232530139: 232530140
8 CHRND NM_000751.2(CHRND): c.820_820+1del deletion Pathogenic rs879255564 GRCh37 Chromosome 2, 233394849: 233394850
9 CHRND NM_000751.2(CHRND): c.188T> C (p.Leu63Pro) single nucleotide variant Pathogenic rs121909508 GRCh37 Chromosome 2, 233391374: 233391374
10 CHRND NM_000751.2(CHRND): c.188T> C (p.Leu63Pro) single nucleotide variant Pathogenic rs121909508 GRCh38 Chromosome 2, 232526664: 232526664

Expression for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Search GEO for disease gene expression data for Myasthenic Syndrome, Congenital, 3b, Fast-Channel.

Pathways for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

GO Terms for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

Sources for Myasthenic Syndrome, Congenital, 3b, Fast-Channel

3 CDC
7 CNVD
9 Cosmic
10 dbSNP
11 DGIdb
17 ExPASy
19 FMA
28 GO
29 GTR
30 HGMD
31 HMDB
32 HPO
33 ICD10
34 ICD10 via Orphanet
35 ICD9CM
36 IUPHAR
37 KEGG
38 LifeMap
40 LOVD
42 MedGen
44 MeSH
45 MESH via Orphanet
46 MGI
49 NCI
50 NCIt
51 NDF-RT
54 NINDS
55 Novoseek
57 OMIM
58 OMIM via Orphanet
62 PubMed
64 QIAGEN
69 SNOMED-CT via HPO
70 SNOMED-CT via Orphanet
71 TGDB
72 Tocris
73 UMLS
74 UMLS via Orphanet
Content
Loading form....