Authors present a case of 38-year-old woman, of whom the first symptoms of the disease were poor exercise tolerance, increasing limitation of motion in the shoulder, elbow and hip joints and bone pain. At the age of 37, the patient presented rapid cardiac symptoms (significantly decreased physical activity tolerance, dyspnea, generalized fatigue). A typical result of heart ultrasound examination together with radiologic features (dysostosis multiplex) suggested mucopolysaccharidosis. Mucopolysaccharidosis type VI (MPS VI) was confirmed by a screening test which revealed the presence of dermatan sulphate and enzyme assay with significantly decreased activity of arylsulfatase B (ARSB). The patient represents relatively attenuated MPS VI with osteo-articular and cardiac changes (Table I, II, Figure 1, 2).