This case represents the first report of IE in an NS patient harboring a pathogenic MRAS mutation (c.203C>T, p.Thr68Ile), underscoring the importance of vigilant cardiac monitoring in syndromic HCM patients, consideration of IE prophylaxis during high-risk procedures, and multidisciplinary management integrating cardiology, genetics, and infectious disease expertise for optimizing outcomes in this complex patient population. The gene discussed is MRAS; the disease is infectious disease.