Living With Myasthhenia Gravis Myasthenia Gravis (MG) is an autoimmune disease (usually inherited- thanks mom!) that occurs when the immune system, in the form of antibodies, attacks, and damages the junction between nerve and muscle. These rogue antibodies target the acetycholine receptors, proteins on muscle cells required for muscle contraction. The ensuing damage to these receptors reduces the muscle's ability to respond to nerve signals. This results in muscle weakness. Muscles that control the eyes, face, throat, and limbs are affected. Symptoms in MG typically occur when the reduction in available acetylcholine receptor sites reaches 30 percent. Most symptoms are related to weakness of skeletal muscle groups, for instance, the muscles involved in climbing stairs or flexing the hands. Cardiac and smooth muscle is not affected. In about 20 percent of patients, vision alone is affected. Typical visual disturbances in MG include diploplia (double vision), ptosis (eyelid droop...