changes interfere with the formation of the mature triple-stranded collagen molecule and prevent the production of mature type I collagen, which results in type IV osteogenesis imperfecta. Osteoporosis: Osteoporosis is a condition that makes bones progressively more brittle and prone to fracturing. A particular variation (polymorphism) in the COL1A1 gene appears to increase the risk of developing osteoporosis. A specific variation at Sp1 binding site is shown to be associated with increased risk of low bone mass and vertebral fracture, because of the changes the COL1A1 protein produced from one copy of the gene. Several studies have shown that women with this particular genetic variation at Sp1 site are more likely to have signs of osteoporosis than are women without the variation. Predisposition to hernias. Predisposition to degenerative disc disease, and disc herniation. References Further reading External links GeneReviews/NCBI/NIH/UW entry on Osteogenesis Imperfecta COL1A1 GeneCard Database of human type I and type III collagen mutations