MUSK and myasthenia gravis: Gender distribution in patients with myasthenia gravis (MG), anti-AChR antibody positive MG (AChR-MG) with early disease onset (EOMG<50 years of age) and late disease onset (LOMG≥50 years of age), anti-MuSK antibody positive MG (MuSK-MG), MG without any of these two antibodies (SN-MG), thymoma associated MG (TAMG) and healthy controls (HC).