Functions of glycosaminoglycans (GAGs)

What is the biological function of the glycosaminoglycans? They are everywhere in your body. They are mainly outside of the cell on the cell surface and in the extracellular matrix. They are connected, they have an absolutely mechanical function in the extracellular matrix but in addition glycosaminoglycans have a very important biological role in cell-cell interaction. What happens if, due to an inborn error in a lysosomal hydrolase, the lysosomal enzyme which should degrade these glycosaminoglycans, is deficient?