COLLAGEN TYPE TYPE DISTRIBUTION I Skin Most abundant II Connective tissue cailage and vitreous humor III Aeries and CVS Healing and Granulation tissue IV Basement membrane Defect lead to Alpo syndrome Gene defect - COL4A3-COL4A6 AUTOSOMAL and X linked Hematuria + OCULER Problem + hearing loss VII Junction of dermal and epidermal Defect lead to Epidermolysis bullosa Gene defect - COL7A1