http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. University of Iowa researchers and colleagues in France have identified a gene variant that causes a potentially fatal human heart rhythm disorder called sinus node disease. Also known as "sick sinus syndrome," the disease affects approximately one in 600 heart patients older than 65 and is responsible for 50 percent or more of the permanent pacemaker placements in the United States. http://www.physorg.com/news142596831.html Medicine & Health Tue, 07 Oct 2008 11:13:51 EST news142596831