Coarse Facial Features

Severely affected individuals look remarkably similar due to the coarsening of their facial features, including short noses, flat faces and large heads. Their heads tend to be longer than normal from front to back “scaphocephalic”, with a bulging forehead. This is because of how the bones of the skull form to create the shape of the skull. Babies’ skulls are soft, and the individual bones are separated by thin, fibrous tissue. These soft spots, normally close during the first few years. In individuals where MPS I progresses rapidly, the bones along the top of the head fuse together earlier than normal, so the skull has to expand more in the front and the back, creating the long head shape and prominent forehead. There is often a ridge across the forehead where the skull has closed prematurely.

Individuals with MPS I typically have a broad nose with a flat bridge and wide upturned nostrils. Their eye sockets tend to be shallow and their eyes tend to protrude slightly. They will have a large tongue, which may stick out. Their body hair is typically coarser and more abundant than usual. People with MPS I may have protruding bellies and stand and walk with a bent-over stance due to joint contractures (stiffness) at the hips, shoulders, elbows, and knees. Individuals will vary considerably in appearance. Adults are often stocky in build and their trunks tend to be shorter than average. Their neck may be short and stiff. The faces of many people with Scheie disease may not appear unusual.

Coarse Facial Features
Courtesy of E. Kakkis, M.D.

Skin

People with MPS I tend to have thickened and tough skin, making it difficult to draw blood or place intravenous catheters. Severely affected individuals may have extra hair on their face and back. If the hands or feet are blue or cold from time to time, a cardiologist should check to see if the heart or the aorta might be responsible for the problem. Heart or aorta problems can lead to poor blood circulation, which can cause cold hands and feet.

Individuals with MPS I may also have Mongolian spots. These are bluish-colored spots that appear on the skin, often in the
lower back area.