Autoreactive B cells with autoantibody formation play a key role in the pathogenesis of MG, and the autoantibodies in the majority of MG patients are directed against the muscle acetylcholine receptor (AChR) of the neuromuscular junction, while in 6% antibodies against the muscle-specific kinase (MuSK) are detected (Gilhus, 2016; Gilhus and Verschuuren, 2015). This evidence concerns the gene MUSK and myasthenia gravis.