| Popis: |
The tissue-specific extracellular matrix is important for normal development and tissue function, and therefore, mutations in genes responsible for ECM components cause a variety of serious inherited connective tissue disorders. In articular cartilage, the collagens are indispensably connected with the characteristic strength of the tissue. Cartilage disorders involve primarily alterations of collagen II, IX, and XI and the cartilage oligomeric protein (COMP). These diseases include a variety of clinical phenotypes from common osteoarthrosis to different types of mostly inherited chondrodysplasias. More than 100 distinct disorders of chondrodysplasias are described with different subclasses and disproportionate stature, short limbs, dwarfism, premature osteoarthrosis, and eye complications are typical findings for most of these disorders. The typical mutations in collagen genes are null mutations that result in the loss of protein and a reduction of total quantity of collagen protein in tissue. In contrast, small deletions or substitutions of bases can lead to the synthesis of mutated α-chains that are able to form a triple-helix. The altered molecule is secreted and results in a compromised supramolecular assembly with altered ECM suprastructures. In general, these human diseases are difficult to treat, especially when the pathological processes start before birth affecting the complete skeleton. |
