The lysosomal storage disorders (LSD) are a diverse group of inherited conditions caused by the defective function of specific lysosomal proteins. It is estimated that there are more than 50 different types. The disease course of these conditions is generally progressive, but the age of onset, nature and severity of symptoms can be variable between the disorders. Common symptoms of lysosomal disorders include hepatosplenomegaly, coarsening of facial features, short stature, corneal clouding, dysostosis multiplex and neurological regression. The combined prevalence of LSDs is estimated to be 1 in 7,000 births.