Equal male and female incidence of myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies against the muscle acetylcholine receptor (AChR).1,2 Such antibodies are detected in 80 to 90% of MG patients (seropositive MG). Disease incidence is age- and sex-related, with two peaks—one in the second and third decades, seen primarily in women, and one in the sixth and seventh decades, seen primarily in men.1 A review of the literature implies that there is a wide range in the frequency of MG. The reported annual incidence of MG ranges from 1.7 to 15 per million, and the point prevalence rate ranges from 3 to 175 per million.3 This variability is probably due to the fact that most of these studies are based on clinical reports involving small numbers of patients and do not seem to reflect real geographic or ethnic differences. Women have a higher prevalence than men, which is generally described as an approximate 2:1 female-to-male ratio.4 Whether this female-to-male ratio …