Gastrointestinal System

Protuberance of the abdomen is commonly observed in patients with severe MPS I and is caused by the progressive hepatosplenomegaly.[1] Many children with severe MPS I suffer periodically from loose stools and diarrhea, sometimes alternating with periods of severe constipation due to storage within ganglion cells of the enteric nervous system. These problems may or may not diminish as the child gets older; they are exacerbated by muscle weakness and diminished physical activity (which progress with age) as well as antibiotic use for other problems.[2]

Individuals with attenuated MPS I on clinical examination tend to exhibit variable protuberance of the abdomen as a result of an enlarged liver, but their spleens may be normal. Hernias occur in attenuated patients perhaps less frequently than in severe patients.[2]

Umbilical hernias (Image 1) are generally not treated unless they are exceedingly large and cause problems. Some gastrointestinal symptoms (diarrhea and constipation) can be controlled by diet – including control of the amount of roughage. Increased roughage and the conservative use of laxatives may help with constipation.

An individual affected by MPS I with an umbilical hernia Courtesy of Hodder/Arnold Publishers


  1. Clarke, L.A. (1997) Clinical diagnosis of lysosomal storage diseases. In: Organelle Diseases. Clinical Features, Diagnosis, Pathogenesis and Management. Applegarth, D.A., Dimmick, J.E., and Hall, J.G. (eds.). Chapman and Hall Medical, London, pp. 37.
  2. Clarke, L.A. and MacFarland, J. 2001 Mucopolysaccharidosis-I (MPS-I). The Canadian Society for Mucopolysaccharide and Related Diseases, Inc., Clarke, L.A., Kaweski, C., Di Ilio, L., and Hahn, S. (eds.). Ticky Graphics & Printing, Vancouver.