Mucopolysaccharidosis type VI: a cardiologist's guide to diagnosis and treatment.

Mucopolysaccharidosis type VI (MPS VI, Maroteaux-Lamy syndrome) is an inborn error of metabolism, with incidences at birth ranging from 1 in 1.5 million to 1 in 43,000 live births. This disorder is rarely considered when evaluating patients with common populational cardiovascular diseases. A significant number of MPS VI patients, however, do present cardiovascular disease and MPS VI should be considered as a potential differential diagnosis for other cardiovascular disorders. This article reviews the clinical features, diagnostic tests and treatment options for MPS VI. Although MPS VI affects many organs and systems of the human body this review focuses on MPS VI diseases of the heart and vessels. The most characteristic cardiac presentation of MPS VI is valvular disease, but heart failure, pulmonary hypertension, cardiomyopathy, fibroelastosis and cardiac conduction system disorders may also occur. Cardiovascular disease in MPS VI patients may emerge silently. An early diagnosis is difficult due to joint stiffness, respiratory system involvement or skeletal malformations that limit exercise capacity and mask the underlining heart failure. This article is supposed to serve as a very practical reference for cardiologists who may come across MPS VI in their daily practices. A greater awareness of cardiovascular manifestations of MPS VI among cardiologists can help to reduce misdiagnosis and promote early detection of this inborn disorder and aid the implementation of adequate therapy at the earliest stage possible which is crucial for its efficacy.