Morquio's syndrome: severe aortic regurgitation and late pulmonary autograft failure

A 44-year-old woman underwent a Ross procedure for severe aortic regurgitation at the age of 32 years. She had been diagnosed in childhood with spondyloepiphyseal dysplasia and a bicuspid aortic valve. At surgery, a tricuspid aortic valve with chondroid metaplasia and fibrosis was reported. Biochemical and genetic evaluation in this patient confirmed the diagnosis of mucopolysaccharidosis IV type B (MPS IV), otherwise known as Morquio's syndrome. This autosomal-recessive inherited syndrome is characterized by the accumulation of keratin sulfate in connective tissue and various other organs. Cardiac (notably valvular) involvement has been well described in the literature. To the authors' knowledge, this is the first reported case of valve replacement or Ross procedure for this condition. This woman presented 12 years after her initial valve surgery with progressive dyspnea. Echocardiographic examination revealed severe pulmonic autograft regurgitation without a dilated aortic root, together with severe stenosis of the pulmonary homograft. It is postulated that the underlying metabolic abnormality may have led to progressive pulmonary autograft failure and to accelerated dysfunction and stenosis of the pulmonary homograft. It is likely that a mechanical prosthesis would have been a better therapeutic option if the preoperative diagnosis of MPS IV had been made.