Myasthenia gravis is not thought to be a genetically inherited disease, according to Myasthenia Gravis Foundation of America. A genetic predisposition to autoimmune disorders can run in families, but myasthenia gravis is not believed to be directly inherited.
Myasthenia gravis is characterised by weakness and fatigue of muscles under voluntary control, explains Myasthenia Gravis Foundation of America. As of 2015, there is no cure for the condition, but treatment helps to relieve symptoms and improve quality of life. Myasthenia gravis is more common in women younger than 40 years of age and in men older than 60. Therapeutic options include medication, plasmapheresis and surgery. Approximately 15 percent of patients with myasthenia gravis have a tumor in the thymus gland, according to Mayo Clinic.