We determined the cardiologic features of children with MPS I, II and VI, and evaluated the effect of enzyme-replacement therapy (ERT) on cardiac disease. Twenty-four children aged 1-18 years with MPS I, II or VI were prospectively evaluated with echocardiogram and electrocardiogram from the start of enzyme-replacement therapy up to 6 years of treatment. At start of therapy, 66% had abnormal cardiac geometric features. Left-ventricular mass index (LVMI) was increased in half of the patients, due mainly to concentric hypertrophy in MPS I and II and to eccentric hypertrophy in MPS VI. Regurgitation was most severe in a subgroup of young MPS VI patients (<5 years) at the mitral valve. At baseline, all patients had abnormal valves. The ECG showed no clear rhythm or conduction abnormalities; neither, in most patients, did it reflect the hypertrophy. After ERT, the LVMI Z-score normalized in 70% of the patients who had a Z-score > 2. LVMI Z-scores decreased significantly in patients with MPS I and MPS II (p = 0.04 and p = 0.032). Despite ERT, valve regurgitation increased in 60% of the patients. We conclude that all our MPS patients have cardiac abnormalities. The most severe cardiac disease was observed in a subgroup of young MPS VI patients. While ERT had an effect on LVMI and IVSd, it apparently had little or none on valve regurgitation.

doi.org/10.1007/s10545-011-9444-z, hdl.handle.net/1765/57300
Journal of Inherited Metabolic Disease
Department of Pediatrics

Brands, M., Frohn-Mulder, I., Hagemans, M., Hop, W., Oussoren, E., Helbing, W., & van der Ploeg, A. (2013). Mucopolysaccharidosis: Cardiologic features and effects of enzyme-replacement therapy in 24 children with MPS I, II and VI. Journal of Inherited Metabolic Disease, 36(2), 227–234. doi:10.1007/s10545-011-9444-z