Patients appear healthy at birth and have accelerated growth in the first year, followed by deceleration and short stature later in childhood. Other complications include hearing loss, chronic respiratory infections, and cardiac insufficiency due to valvular disease. MPS VI is characterized by substantial morbidity due to progressive accumulation of GAGs. Although mental development is normal, physical and visual defects can adversely affect psychomotor development. Growth may be normal for the first few years of life but then stops, resulting in dwarfism.
Most patients have corneal clouding, which can interfere with vision.
Restricted joint movement is a common feature, and patients develop claw-hand deformities due to contractures. Cardiac involvement includes aortic and mitral valve dysfunction. Skeletal changes are typified by dysostosis multiplex. Patients also may develop obstructive airway disease. Age at death is variable, and mild forms of the disease have been described with prolonged survival.