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Congenital myasthenic syndrome

Congenital myasthenic syndrome

Reviewed November 2011

What is congenital myasthenic syndrome?



How common is congenital myasthenic syndrome?

The prevalence of congenital myasthenic syndrome is unknown. At least 600 families with affected individuals have been described in the scientific literature.

What genes are related to congenital myasthenic syndrome?

Mutations in many genes can cause congenital myasthenic syndrome. Mutations in the CHRNE gene are responsible for more than half of all cases. A large number of cases are also caused by mutations in the RAPSN, CHAT, COLQ, and DOK7 genes. All of these genes provide instructions for producing proteins that are involved in the normal function of the neuromuscular junction. The neuromuscular junction is the area between the ends of nerve cells and muscle cells where signals are relayed to trigger muscle movement.

Gene mutations lead to changes in proteins that play a role in the function of the neuromuscular junction and disrupt signaling between the ends of nerve cells and muscle cells. Disrupted signaling between these cells results in an impaired ability to move skeletal muscles, muscle weakness, and delayed development of motor skills. The respiratory problems in congenital myasthenic syndrome result from impaired movement of the muscles of the chest wall and the muscle that separates the abdomen from the chest cavity (the diaphragm).

Mutations in other genes that provide instructions for proteins involved in neuromuscular signaling have been found to cause some cases of congenital myasthenic syndrome, although these mutations account for only a small number of cases. Some people with congenital myasthenic syndrome do not have an identified mutation in any of the genes known to be associated with this condition.

Read more about the CHAT, CHRNE, COLQ, DOK7, and RAPSN genes.

See a list of genes associated with congenital myasthenic syndrome.

How do people inherit congenital myasthenic syndrome?



Where can I find information about diagnosis or management of congenital myasthenic syndrome?

Where can I find additional information about congenital myasthenic syndrome?

You may find the following resources about congenital myasthenic syndrome helpful. These materials are written for the general public.


What other names do people use for congenital myasthenic syndrome?

  • CMS
  • congenital myasthenia
  • congenital myasthenic syndromes


What if I still have specific questions about congenital myasthenic syndrome?

Where can I find general information about genetic conditions?

What glossary definitions help with understanding congenital myasthenic syndrome?

apnea ; autosomal ; autosomal dominant ; autosomal recessive ; cell ; congenital ; cyanosis ; gene ; infection ; inherited ; motor ; muscle cells ; mutation ; neuromuscular junction ; prevalence ; recessive ; respiratory ; syndrome


See also Understanding Medical Terminology.

References (6 links)



Reviewed: November 2011
Published: December 16, 2014