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GTR Home > Conditions/Phenotypes > Congenital myasthenic syndrome 4B

Congenital myasthenic syndrome 4B

Synonyms
Myasthenic syndrome, congenital, 4b, fast-channel

Summary

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 AChR 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). [from OMIM]

Available tests

38 tests are in the database for this condition.

Clinical tests (38 available)

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: ACHRE, CMS1A1, CMS1D, CMS1E, CMS2A, CMS4A, CMS4B, CMS4C, FCCMS, FIM1, FIMG, FIMG1, MGI, SCCMS, CHRNE
    Summary: cholinergic receptor nicotinic epsilon subunit

Clinical features

Help
Imported from Human Phenotype Ontology (HPO)

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