Additionally, 5%–10% of AChR-RIPA-negative MG patients have antibodies against Muscle-Specific Kinase (MuSK) or Low-Density Lipoprotein Receptor-Related Protein 4 (LRP4), yet some MG patients remain seronegative (SNMG) (5). The gene discussed is MUSK; the disease is myasthenia gravis.