"These genes do not have a diagnostic value, because their impact on individuals is rather small," Stefansson said. "Although these genes explain a very large part of the disease in our society, because just one loci we found explains 17 percent of all cases of osteoporosis in the population."
One expert thinks that these genes are only a small part of the story of osteoporosis.
"Taken together, these genes only account for 3 percent of variation in bone density," said Dr. J. Chris Gallagher, a professor of medicine and endocrinology at Creighton University School of Medicine in Omaha, Neb., and a board member of the North American Menopause Society.
Gallagher noted that a couple of these genes, including the osteoporosis gene and RANKL, are already being looked at as targets for drug therapy.
Moreover, these genes are not strong predictors of osteoporosis, Gallagher said. "It means there are many more things involved that contribute to the overall picture," he said.
In a second study, published in the April 29 early online edition of The Lancet, an international team of researchers reported identifying two genetic variants that, when present together, significantly increase the risk of osteoporosis and bone fractures.
These variants are found in 22 percent of the people studied, perhaps making them targets for screening, the researchers noted. Having both of these variants increases the risk for osteoporosis by 20 percent and the risk for osteoporosis-related fractures by 30 percent, the researchers reported.
The researchers concluded that these gene variants "could be used in the future, in addition to traditional risk factors, to better identify populations who are at high risk for osteoporotic fractures."
More information
For more about osteoporosis, visit the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases.
