An individual affected by MPS I with an umbilical hernia
Courtesy of Hodder/Arnold Publishers
Inguinal and umbilical hernias are commonly seen in patients with MPS I and are often the first observed manifestation. Patients with MPS I also often experience hepatosplenomegaly, usually manifested as a protruding abdomen. The glycosaminoglycan accumulation in the liver and spleen does not usually cause abnormalities besides the enlarged appearance of these visceral organs.
Children with MPS I also often develop alternating periods of constipation and diarrhea which may or may not improve with age. The etiology of this is not known but some possible contributing factors are myopathy, a sedentary lifestyle and antiobiotic usage (for other conditions).
In MPS I, glycosaminoglycan (GAG)-engorged cells accumulate and displace healthy normal cells in tissue and organs such as the liver and spleen, causing a host of signs, including skeletal deformities, coarse facial features, and an enlarged liver and spleen.