How common is Myasthenia Grevis
What is the epidemiology of MG (i.e., incidence, gender differences, age of onset, inheritance, mortality, and natural history)?
The incidence of Myasthenia Grevis is approximately 1 in 20,000.
It affects more women than men by a ratio of 3:2 and has a bimodal age distribution (affecting more women in the third decade and more men in the fifth decade), although it may appear at any age from birth to late adulthood.
Five to seven percent of cases are familial, but no Mendelian inheritance pattern has been identified.
Prior to the advent of effective immunomodulatory therapy and artificial ventilation, 20% to 30% of Myasthenia Grevis patients died due to respiratory failure, 20% experienced persistent symptoms, 25% experienced spontaneous improvement, and a final 25% experienced spontaneous remission.
In the modern era, Myasthenia Grevis is eminently treatable, and death in the properly treated and adherent patient is rare.
