Tabriz University of Medical Sciences BioImpacts 2228-5652 3 4 2013 12 27 Lysosomal Storage Diseases: Heterogeneous Group of Disorders 145 147 10.5681/bi.2013.029 EN David A. Wenger Paola Luzi Mohammad A. Rafi EDITORIAL 10.5681/bi.2013.029 2014 01 13 The name of lysosomal storage diseases stems from the fact that in this category of disorders specific undegraded materials are stored in the lysosomes. This is usually caused by a lysosomal enzyme deficiency and leads to a cascade of pathological outcomes. Apart from deficiency of lysosomal enzymes, lysosomal storage diseases also include deficiencies in proteins necessary for enzyme functioning, proteins needed for post-translational modification of these enzymes and proteins required for export of certain compounds from the lysosomes.