Type H Ref: Harper 26/e p.536 Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals, making up about 25% of the whole-body protein content. Tough bundles of collagen called collagen fibers are a major component of the extra cellular matrix that suppos most tissues and gives cells structure from the outside, but collagen is also found inside ceain cells. Collagen has great tensile strength, and is the main component of fascia, cailage, ligaments, tendons, bone and teeth. 19 types of collagens have been found (so far) in humans. Over 90% of the collagen in the body, however, are of type I, II, III, and IV. Type Tissues Gene(s) Genetic Disorders This is the most abundant collagen of the I human body.found in most connective tissues including bone. COL1AI,COL1A2 Osteogenesis imperfecta type!, Ehlers-Danlos Syndrome type 7 II Cailage, Vitreous humor COL2A I Collagenopathy, types II and XI Frequently found with type I in skin, muscles, and blood vessels. Strengthens the walls of hollow extensible structures like aeries, the intestine, and the uterus. III COL3A 1 Ehlers-Danlos Syndrome type 4 This is the collagen of granulation tissue, and is produced quickly by young fibroblasts before the tougher type I collagen is synthesized IV Basement membrane (serves as pa of the filtration system in capillaries and the glomeruli of nephron in the kidney.). Eye lens COL4A1- COL4A6 Alpo syndrome V Most interstitial tissue, assoc. with type I, associated with placenta COL5A1, COL5A2, COL5A3 Ehlers-Danlos syndrome (Classical) VI Most interstitial tissue, assoc. with type I COL6A1, COL6A2, COL6A3 Ulrich myopathy and Bethlem myopathy VII Forms anchoring fibrils in dermal epidermal junctions COL7A1 Epidermolysis bullosa