Infective endocarditis associated with mitral valve prolapse in a patient with Klinefelter syndrome.

We herein report a case of infective endocarditis associated with mitral valve prolapse (MVP) in a 34-year-old man with Klinefelter syndrome. The patient was admitted with a fever and headache that had persisted for three weeks. Repeated blood cultures showed growth of Streptococcus oralis. Echocardiography demonstrated severe mitral regurgitation with a large vegetation attached to the prolapsed anterior leaflet. Surgical plasty of the mitral valve was performed because the vegetation measured over 10 mm in diameter and there was a risk of recurrence of embolic complications. This case demonstrates the link between MVP and Klinefelter syndrome and highlights the importance of performing cardiovascular screening and preventing endocarditis.