Oligosaccharides are chains of sugar molecules used in the building of bones, cartilage, skin, tendons and many other tissues in the body. “Oligo” means a few and “saccharide” is a general term for the sugar part of the molecule. In the course of normal life there is a continuous recycling process of building new oligosaccharides and breaking down old ones. The breakdown and recycling process requires a series of special biochemical tools called enzymes.
People with fucosidosis are missing or are low in an enzyme called alpha-L-fucosidase which is essential in breaking down oligosaccharides. When oligosaccharides are not completely broken down they remain stored in the body. The symptoms of fucosidosis are a result of the build-up of oligosaccharides in the tissues in the body. Babies may show little sign of the disease but as more and more cells build up with partially broken down oligosaccharides, symptoms start to appear.