The patient is a 73-year-old male with medical history of diabetes mellitus, hypertension, chronic obstructive pulmonary disease, and obesity grade 2, plus myasthenia gravis of two years of diagnosis, with positive antibody titers against acetylcholine (normal value by immunoradiometric assay <0.25 nmol/L; patient value 6.5 nmol/L) and anti-MuSK (normal value by enzymatic immunoassay <0.4 U/mL; patient value 4.2 U/mL), treated with pyridostigmine (60 mg every 4 hours), azathioprine (50 mg twice a day), and prednisone (5 mg once a day). This evidence concerns the gene MUSK and myasthenia gravis.