Myasthenia Gravis

Home » Myasthenia Gravis » Causes and Risk Factors

Questions to Ask Your Doctor about Myasthenia Gravis
(Free Handout)

Causes and Risk Factors

MG usually is caused by a malfunction of the immune system. The causative factor is unknown, but the disorder may have a genetic link. Causes include a genetic defect, which results in congenital MG, and the circulation of maternal antibodies through the placenta, which result in transient neonatal MG.

Acetylcholine (ACh) is a neurotransmitter that is involved in the transfer of information to muscle tissue. In myasthenia gravis, cells that bind to other cells to neutralize or destroy them (called antibodies) destroy acetylcholine receptor sites (AChR) in areas of muscle tissue that receive nerve impulses (called neuromuscular junctions), preventing nerve impulses from reaching the muscles. This results in weakness and rapid fatigue in affected muscles.

MG may be associated with other autoimmune diseases. Patients with family members who suffer from disorders such as rheumatoid arthritis, scleroderma, and lupus may have an increased risk for myasthenia gravis.

The thymus is an organ that produces cells involved in immune responses. It is located below the larynx and above the heart. Approximately 15% of MG patients have a tumor of the thymus (thymoma) and 60–80% have abnormal enlargement (hyperplasia) of the thymus.

© 1998-2009 Healthcommunities.com, Inc. All Rights Reserved.

Myasthenia Gravis Resources

	Join Our Myasthenia Gravis Forum Do you have a question, want to share medical advice, or just need to discuss your situation with someone else having a similar experience? The healthchannels forum is a resource for everyone to share and discuss their health and medical needs with others.	Advertising Disclaimer
	Living with...Share your story Do you have a personal health story that you would like to share with others? As a source of free patient education, our goal is to provide our users with trustworthy information and support from others. That's why we've started our "Living with..." sections.
	Our "Living With..." support pages are a place to share experiences about living with a certain condition, disease, disorder, or illness and for loved ones of those dealing with health-related issues. Many people, especially when newly diagnosed, find comfort in knowing that others are having a similar experience. Help others by sharing your story. View stories already submitted.
	Stay Updated Sign up for our newsletter and receive important updates on the medical conditions that are most important to you.
To quickly access health information from your website's browser, download Healthcommunities.com's healthchannels toolbar.