The long name for this gene is Collagen Type I Alpha 1 Chain. It is a gene that codes a part of the collagen that is an essential part of bone, cornea (which is the front part of the eye), dermis (skin), and tendons (string attaching a muscle to bone). Genetic variations in this gene may result in imperfect bone formation, resulting in lower bone density, a risk factor for osteoporosis. But also relationships with the occurrence of Ehlers Danlos syndrome have been established. This syndrome causes very loose joints and abnormally stretchy skin. This all makes sense, as collagen is an important structural component of all the involved tissues, and if the genetic code is causing imperfect synthesis of this component, the resulting tissue will be not normal. The normal code is G:G, and for people with T:T, there is a twice as high risk for bone loss, and osteoporosis. Also it has been proven in several studies that people that have suffered from hip fracture, are more likely to have this T:T genotype. These people need extra calcium and vitamin D, as well as vitamin C, in order to promote the body to synthesize more bone tissue, and they will get an additional advice to reduce the intake of bone-break down nutritional components such as oxalic acid. The results mentioned here come from many studies, but I wanted to mention one of them: a study published in Calcified Tissue International. A great example of how our genotype risk analysis is done. 6752 women were tested for a number of genetic variations, and followed for 14.5 years, observing how many fractures occurred in those women. Then it is possible to link genotypes to the risk of bone fractures. A very practical, and conclusive approach!
These kind of studies form the consistent basis for the GenTest analysis results determining your risk profile based on your genotype.