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GTR Home > Conditions/Phenotypes > Congenital myasthenic syndrome 2A

Congenital myasthenic syndrome 2A

Synonyms
Myasthenic syndrome, congenital, 2a, slow-channel

Summary

Slow-channel congenital myasthenic syndrome (SCCMS) 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 prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; cholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462). [from OMIM]

Available tests

21 tests are in the database for this condition.

Clinical tests (21 available)

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: ACHRB, CHRNB, CMS1D, CMS2A, CMS2C, SCCMS, CHRNB1
    Summary: cholinergic receptor nicotinic beta 1 subunit

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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