Cardiac investigation in patients with MG with unexplained fatigue should comprise a physical examination including third tone, holosystolic murmurs, ankle swelling, or lung rales; laboratory findings including brain natriuretic peptide (BNP) [8–10] and cardiac troponin [4]; 6-minute walk distance [13]; and echocardiography along with ECG. The gene discussed is NPPB; the disease is myasthenia gravis.