Congenital Myasthenic Syndromes (CMS)

Signs and Symptoms

As its name implies, congenital myasthenic syndromes (CMS) usually have a congenital (at or near birth) onset, but the disease can manifest in children and even in adults. The different types vary in the kind and degree of symptoms, but generally speaking, the earlier the symptoms appear, the more pronounced the disease is likely to be.

Types of CMS

Presynaptic CMS

This type of CMS is characterized by insufficient release of ACh (a chemical necessary for proper muscle function). It commonly manifests as CMS with episodic apnea (CMS-EA), which has its onset in infancy and causes weakness of the facial muscles and those involved in swallowing and talking, as well as episodes of apnea, a temporary cessation of breathing.


What are congenital myasthenic syndromes (CMS)?

Illustration of the neuromuscular junction
CMS results from genetic flaws at the neuromuscular junction — where the nerve cell meets the muscle cell.

Congenital Myasthenic Syndromes


MDA leads the search for treatments and therapies for congenital myasthenic syndromes (CMS). The Association also provides comprehensive supports and expert clinical care for those living with CMS.

In this section, you’ll find up-to-date information about congenital myasthenic syndromes, as well as many helpful resources. This information has been compiled with input from researchers, physicians and people affected by the disease.

Researchers Exploring Disability Perceptions

Researchers at the Psychology of Disability Lab at the University of Michigan in Ann Arbor are exploring the social identity of people with disabilities through a short, anonymous, Web-based questionnaire.

The lab's Disability Identity Project is being headed by principal investigator Adena Rottenstein, a doctoral candidate in psychology.

The study closes the week of Aug. 22, 2011.

Research Briefs: CMS, DMD, LGMD, Pompe, Stem Cells

Congenital myasthenic syndromes

A multinational team of scientists has identified mutations in the gene for glutamine-fructose-6-phosphate transaminase 1 (GFPT1) as responsible for some forms of a congenital myasthenic syndrome (CMS).

Research Briefs: CMT, CMS, DMD/BMD, FA, Pompe disease, SBMA

MDA Awards More Than $14 Million in Research Grants

MDA has awarded 38 new research grants totaling more than $14 million and covering more than a dozen neuromuscular diseases. 

MDA's Board of Directors met in Los Angeles July 16, where it reviewed and approved the new grants based on recommendations from the MDA Scientific and Medical Advisory Committees. Grants were scored and recommended for approval based on the capabilities of the applicant, the scientific merit of the project, and the proposal's relevance to developing treatments for the disease. The effective start date for all grants was July 1, 2010.