[Lysosomal storage diseases--an overview]

Lysosomal storage diseases (LSD) are a group of fifty or so metabolic disorders. They are caused by genetic defects causing a lack or severe deficiency in activity of one of proteins belonging to four functional groups: acid lysosomal hydorlases involved in degradation of various macromolecules, proteins involved in lysosomal transportation, proteins required to deliver enzymes into lysosomes or activators of lysosomal enzymes. Due to their deficiency, undegraded or partially degraded macromolecules accumulates in lysosomes, causing dysfunction of cells, tissues and organs. Most LSDs are inherited in autosomal recessive manner. There are only three exceptions: Fabry disease and Hunter disease (mucopolysaccharidosis type II), which are X-linked recessive disorders, and Danon disease, which is an X-linked and dominant. As significant advantages have been achieved in understanding of LSD pathomechanisms, these diseases became examples of the importance of biochemical, genetic, molecular and biotechnological studies in development of diagnostics, understanding of biological mechanisms of diseases and development of modern therapeutical methods. In this article, an overview on LSD is presented, while more detailed description of some groups of these diseases: lipidoses, glycogenoses and mucopolysaccharidoses, will be presented in subsequent articles included in this issue.