congenital hypoplasia of the mitral valve annulus
Hypoplasia of the mitral valve annulus is a rare, congenital, mitral valve malformation characterized by hypoplastic annulus which usually appears within a complete mitral valve hypoplasia, causing mitral valve stenosis. Association with other cardiac malformation is common, including coarctation of the aorta, aortic valve stenosis, Shone complex and hypoplastic left heart syndrome.