Imagine if your doctor could prescribe medicine to you based on your specific genetic makeup; medicine that was designed to work with your specific body. Researchers took a major step in that direction yesterday when they unveiled the first map of common human genetic variations. This discovery could lead doctors to forecast people's risks for specific diseases and tell them which treatments have the best chance of success.

The map was created by Perlegen Sciences Inc., and shows SNPs or 'snips' which are tiny bits of genetic information that each person carries on their genes. Most people have DNA that is 99.9 percent identical but those small genetic differences can change the way a person reacts to a disease or a treatment for that disease. The same scientists hope to unveil a more detailed genetic map later this year.

One example given by Lawrence Lesko who is in charge of gene-based medicine for the FDA is this: only a small number of smokers get lung cancer and only 10 percent of lung cancer patients respond to lung cancer therapy. Doctors still don't know who will respond and why. This new discovery may be the first step to finding some answers to those potentially life saving questions.