After adjustments for age, thymus status, thymectomy, AChR-Ab, MuSK-Ab, Osserman classification, involvement of pharyngeal muscles, acetylcholinesterase inhibitor use, and immunosuppressant use, we established a significant negative association between Ln(PNKc) and 1-year relapse risk in patients with MG. This evidence concerns the gene MUSK and myasthenia gravis.