Myasthenia gravis, AChR antibody positive (Q88659)

Acetylcholine receptor (AChR) positive Myasthenia Gravis (MG) is the most prevalent type of MG. The antibodies are directed against postsynaptic proteins, usually the nicotinic acetylcholine receptor, making up 80% of all generalised MG patients. Fluctuating weakness increasing with repeated activity and improving after a period of rest is the characteristic hallmark. Half of the ocular MG patients (manifesting with fluctuating ptosis and diplopia) are AChR positive. 90% of early-onset (<40-50 years) generalised MG patients, typically females, are positive for AChR antibodies and usually have thymus hyperplasia. Most late-onset patients (either male or female) are also AChR positive and have atrophic thymuses.