Ehlers-Danlos syndrome skin collagen defects

The conversion of procollagen to collagen by removal of propeptides seems to be essential for the formation of collagen fibrils. This supposition is supported by studies of two heritable diseases, one found in humans and the other in cattle, sheep, and cats. In both, the defect lies in the removal of N-terminal propeptides and results in impaired fibril formation. The human disorder is the type VII variant of Ehlers-Danlos syndrome (Table 25-5). Affected individuals exhibit marked joint hypermobility, dislocation of joints, short stature, and minor changes in skin elasticity. Their skin fibroblasts show normal... 

Several collagen disorders result from defects in the formation of cross-links (Chapter 11). The cross-linking disorders can be due to a hereditary deficiency of lysyl oxidase, inhibition of lysyl oxidase, deficiency of copper, defects in the formation of cross-links, or defects in their stabilization. The genetic deficiency of lysyl oxidase is characterized by Ehlers-Danlos syndrome type IX (Table 25-5) and some forms of cutis laxa. Type IX Ehlers-Danlos syndrome patients exhibit extreme extensibility of the skin, cigarette-paper scarring, and easy bruisability. In cutis laxa, the skin is loose and inelastic and appears to be too large for the surface it covers. Some affected individuals exhibit deficiency of lysyl oxidase, presumably... 

Kurata, S. 1., Senoo, H., and Hata, R.-i., 1993, Transcriptional activation of type 1 collagen genes by ascorbic acid 2-phosphate in human skin fibroblasts and its failure in cells from a patient with a2(I)-chain-defective Ehlers-Danlos syndrome, Exp. Cell Res. 206 63-71. 

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