Medical Mystery of the Week

       You are asked to make a diagnosis in this 24-year-old man based on his picture and a recording of his heart sounds (see below).
      DIAGNOSIS: Mitral valve prolapse in a patient with Marfan's syndrome (MFS).
     MFS is an autosomal dominant multisystem connective tissue disorder with an estimated prevalence of one in 3,000 to 5,000 individuals. The primary genetic defect lies on chromosome 15q21.1 within the coding region for the fibrillin-1 (FB-1) gene. FB-1 is a large glycoprotein produced and secreted by fibroblasts and incorporated into the extracellular matrix of tissues as insoluble microfibrils. These microfibrils serve as a scaffold for the deposition of elastin and for the sequestration of latent transforming growth factor (TGF)-ß thus preventing unregulated stimulation of the TGF-ß pathway.
      Clinical manifestations of MFS may include aneurysmal dilation of the aortic root (in most instances the ascending aorta and arch maintain their normal dimensions leading to an "Erlenmeyer flask" shaped  aneurysm), aortic rupture or dissection, mitral valve prolapse, cardiomyopathy, arachnodactyl, scoliosis, pectus deformities, increased joint laxity, enophthalamos, hypertelorism, ectopia lentis, dural ectasia, spontaneous pneumothorax, and striae atrophica.
      The diagnosis of MFS is based on clinical findings, the family history and genetic testing. MFS patients should have biannual echocardiographic imaging to quantify aortic root dimensions and mitral valve integrity. They should avoid high impact and isometric exercises and competetive athletics. The use of beta blockers is contraversial.      

The patient has arachnodactyl and some joint laxity (left image). Systolic and diastolic clicks and a midsystolic murmur are present in the heart recording. These findings are characteristic of mitral valve prolapse (right image).