Introduction Mucopolysaccharidosis (MPS) belongs to the group of lysosomal storage diseases associated with the partial or total deficiency of 11 different lysosomal hydrolases responsible for glycosaminoglycan (GAG) degradation. GAG accumulation may affect the valves, myocardium, and coronary vessels. The forms that accumulate dermatan sulfate (MPS I, II, VI, and VII) are associated with valvular thickening (L > R). MPS is one of the most common causes of mitral annulus thickening in children. Cardiac involvement also includes hypertrophy, tendinous cord shortening, […]