Echocardiographic study of paediatric patients with mucopolysaccharidosis

Principle: Mucopolysaccharidosis is an inborn error of metabolism causing glucosaminoglycans tissue storage. Cardiovascular involvement is variable but contributes significantly towards the morbidity and mortality of the patients. Objective: To characterise the echocardiographic abnormalities in children and adolescents with different types of mucopolysaccharidosis. Method. Echocardiograms and medical records of 28 patients aged 2-14 years, seen from 2003 to 2005, were revised. At that time, the enzymatic replacement therapy was still not available in our institution. Results: Echocardiographic alterations were detected in 26 patients (93%), whereas 16 (57%) had abnormal auscultation, and only 6 (21%) presented with cardiovascular complaint. Mitral valve thickening with dysfunction (regurgitation, stenosis, or double lesion) was diagnosed in 60.8%, left ventricular hypertrophy in 43% and aortic valve thickening with regurgitation in 35.8% of the patients. There was no systolic dysfunction and mild left diastolic dysfunction was shown in 21.5% of the patients. Pulmonary hypertension was present in 36% of the patients, causing the only two deaths recorded. There was a strong association between the accumulation of dermatan sulphate and the presence of mitral valve dysfunction (p = 0.0003), aortic valve dysfunction (p = 0.006), and pulmonary hypertension (p = 0.006). Among individuals with two or more examinations, 82% had a worsening evolution. Conclusions: Echocardiographic alterations in children with Mucopolysaccharidosis are frequent and have a progressive character. Left valve lesions, ventricular hypertrophy, and pulmonary hypertension were the most common findings and there was an association between the accumulation of dermatan sulphate and cardiovascular involvement. Unlike in adults, pulmonary hypertension was the main cause of death, not left ventricle systolic dysfunction.