<prompt> A 5-year-old boy is referred to a pediatric cardiologist after a check-up at his GP revealed he had a murmur consistent with aoic regurgitation. What is the MOST likely cause of this defect?Atrial septal defectRheumatic feverCardiomyopathyVentricular septal defect  <response>: Option A: ASD Shunt murmur absent, flow murmur is mid diastolic murmur. Option B: In Rheumatic- mc valve involved is Mitral 2nd mc Aoic valve, but in 5 yr. old child only Aoic regurgitation is seen rare Option C: HOCM causes Systolic murmur DCMFunctional MR TR Systolic Murmur Option D: Ventricular septal defect 3 varieties Muscular Membranous Supra-Cristal variety with associated with AR In 5 year child rheumtic hea disease involving isolated aoic valve is unlikely .most common valve involved in RHD is mitral valve. 