Mitral valve prolapse and type II mucopolysaccharidosis: Two familial cases

Type II mucopolysaccharidosis (Hunter's disease) is a hereditary condition due to a deficit of a lysosome specific hydrolase (iduronate sulfatase) ind ucing an accumulation of dermatane-sulphate and heparane-sulphate in certai n organs. Cardiac involvement is constant in this disease and manifests its elf essentially by aortic valve stenosis and insufficiency and/or mitral in sufficiency which is progressive, irreversible and life-threatening. Two brothers of Portuguese nationality suffering from a so-called slight fo rm of this disease had classical mucopolysaccharide infiltration of their a ortic valves. The elder brother, aged 11, had severe aortic insufficiency a ssociated with mild stenosis requiring treatment with vasodilator drugs. Th e younger, aged 8, had asymptomatic mild aortic regurgitation. Curiously, m itral valve prolapse with regurgitation was present in both children. The a ssociation of mitral valve prolapse and type II mucopolysaccharidosis, with out other typical cardiac involvement, has only been reported once in the l iterature.