Last reviewed 01/2018
Collagen is the most abundant protein within the body. Its high tensile strength and relative inelasticity make it an important component of connective tissue. It is found in bone, skin, cartilage and ligaments.
There are four subtypes of collagen according to minor differences in the amino acid sequence of the primary polypeptide chain and its post-translational modification. Further, the subtypes tend to associate with particular tissues e.g. type II collagen with cartilage and type IV collagen with basement membranes.
The collagen vascular diseases are a loosely-associated group of conditions in which a collagen disorder is purported to be of aetiological importance.