Overview: Myasthenia Gravis
Myasthenia Gravis (MG) is an autoimmune disorder that affects the neuromuscular junction, meaning the method by which the nerves tell the muscle to contract. It specifically affects a receptor for the neurotransmitter nicotinic acetylcholine (ACh). In MG, there are autoantibodies that are produced that interfere with these receptors. These antibodies can be detected on blood testing in up to 90% of people who have MG. MG occurs about twice as often in women than men and has a prevalence of about 1 in 10,000 to 20,000 people. The symptoms often peak in the second and third decades of life in women and the fifth and sixth decade of life in men, but it can occur at any point in life. MG tends to co-occur with other autoimmune disorders, such as rheumatoid arthritis, autoimmune thyroid disease, or lupus.