British researchers have identified two common genetic mutations that increase the risk of osteoporosis and related bone fractures, according to a study.
These changes were present in 20 percent of the people studied and highlight the potential role of screening for the bone-thinning disease that mainly affects women after menopause, they reported in The Lancet medical journal.
"Eventually, a panel of genetic markers could be used in addition to environmental risk factors to identify individuals who are most at risk for osteoporotic fractures," Tim Spector and Brent Richards, researchers at King's College London wrote.
Osteoporosis is a condition where bone density thins as more bone cells are lost than replaced when people age. It affects about one in three women and one in five men around the world, according to the International Osteoporosis Foundation.
Bone mass increasing drugs could cut fracture risk too
Drugs called bisphosphonates are used primarily to increase bone mass and cut the risk of fractures in patients with osteoporosis.
These include Merck & Co Inc's Fosamax, which US researchers showed may increase the risk of a type of abnormal heartbeat.
In the Lancet study, the team scanned the genes of 2 094 female twins and identified a link between decreased bone mineral density and changes in chromosomes 8 and 11.
In chromosome 11 the change was associated with a 30 percent increased risk of the condition and related fractures and for chromosome 8 the mutation raised risk by 20 percent. For people who had both changes, their risk went up by 30 percent.
These two genes are important target for treatments, and drugs are already under development, the researchers said.
"These (genes) can be measured with near perfection and without bias years before the age at which fractures tend to occur - which could provide ample lead-time for preventative measures," the researchers wrote.
What the findings mean
The findings are an important step forward toward better understanding of the genetic basis of osteoporosis, other researchers wrote in a Lancet commentary.
But work is needed among other populations because the research focuses on mostly white women of European descent, Joseph Zmuda, a researcher at the graduate school of public health at the University of Pittsburgh wrote.
"The effects of (the genes) will also need to be investigated in men and individuals of non-European ancestry," he said. – (Reuters Health, May 2008)