It has long been established that stature is heavily affected by a person’s genetic inheritance, which accounts for about 90 percent of the variation in height between people who have similar diets. While the effect of HMGA2 is small, and tens if not hundreds of other genes are also involved in height, it is the first common gene shown to have a direct link. Very rare mutations that cause growth disorders have been pin-pointed before, but not genes that influence normal variation.The gene was found by the same British team that discovered FTO, the first common gene known to contribute to obesity. Just as FTO is not a “fat gene”, HMGA2 is just one of many biological factors that affect height. It would not be possible to guarantee having a tall child by screening embryos for those with the “tall” variant, the scientists said.