Mild to severe developmental delays are common and mental retardation has been reported in some cases. There is often 'pebbling' of the skin over the neck and chest. Joint stiffness, short stature, and skeletal deformities are common. Many have short necks, a protuberant abdomen, a broad chest, and facial coarseness. Hepatosplenomegaly, hearing loss, hernias, and carpal tunnel syndrome are often present. The skull is large with a J-shaped sella, the vertebral bodies are hypoplastic anteriorly, the pelvis and femoral heads are hypoplastic and the diaphyses are expanded.
A severe form, type A, has its onset in the first two to four years of life, with more rapid progression and death commonly by adolescence. Many patients have obstructive pulmonary disease and heart failure. The IDS deficiency is similar to that of type B which is less severe and compatible with life into the 7th decade. Intelligence is often normal in type B.