Lysosomal diseases of man and domestic animals

Lysosomes constitute a group of heterogeneous cellular organelles, which co ntain various enzymes. These enzymes are required for degradation of comple x macromolecules such as glycolipids, glycoproteins, mucopolysaccharids, mu colipids, etc. Lysosomal diseases mostly result from a genetic defect of ly sosomal enzymes (Sandhoff and Tay-Sachs diseases), rarely from xenobiotics. Mutations in genes controlling intracellular trafficking have also been in volved in the pathogenesis of lysosomal diseases (Batten disease, Niemann P ick type C disease, Chediak Higashi syndrome). The limited degradation of m acromolecules and their accumulation leading to lysosomal overloading contr ibute to clinical injury, especially to organ hypertrophy. Lysosomal diseas es have various clinical features but they precociously affect the nervous system, the skeleton, the spleen and the liver, and progressively result in death. The diagnosis, based on genetic, histological and biochemical crite ria, is difficult. However, new therapeutic approaches, as gene therapy, em erge that aim to introduce the active protein into the organism with suffic ient stability.