Antibodies in Myasthenia Gravis and Related Disorders

Myasthenia gravis (MG) is caused in the majority of cases by circulating autoantibodies to the nicotinic muscle acetylcholine receptor (AChR). Several studies have now documented a higher incidence of AChR-positive MG in both men and women over age 60 years than among younger individuals (Vincent et al. JNNP in press). Since MG can be misdiagnosed as stroke or motor neuron disease in the elderly, it is likely that there is considerable underdiagnosis of MG in this age group. Fetal AChR antibodies and arthrogryposis maternal antibodies to the fetal isoform of the AChR are found in rare cases of arthrogryposis mul…