MuSk Antibodies were first time identified in a myasthenia gravis patient in 2001.4 Although rare, myasthenia gravis is the most common disorder of the neuromuscular junction, with an annual incidence of 0.25-2 patients per 100,000,5 and it is estimated to affect more than 700,000 patients worldwide.6 This evidence concerns the gene MUSK and myasthenia gravis.