Congenital myasthenic syndrome (CMS) is a disorder that causes muscle weakness, induced, or made worse by exertion.
In some patients, this muscle weakness is confined to the face, eyes, and mouth, causing drooping or abnormally relaxed muscles. Other patients observe limb and torso muscle abnormalities as well. There are currently no treatments for this disorder due to the rarity of it, but there are medications and therapies that have been used to help with symptoms.
This group of conditions is caused by pathogenic (disease-causing) variants in the CHRNE gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background.
Resources:
Myasthenia Gravis Foundation of America
Written August 2024
