Such an instability could well contribute to the disease mechanism in human patients and has been reported to be involved for mutations in COL2A1 causing Kniest dysplasia [32], in COL3A1 causing Ehlers-Danlos syndrome type IV [33] and in COL17A1 causing junctional epidermolysis bullosa [34]. Here, COL2A1 is linked to Kniest dysplasia.