IDENTIFICATION OF DISEASE GENES BY POSITIONAL CLONING

Positional cloning or reverse genetics is a combination of techniques that has been extraordinarily successful in finding the genes that cau se many inherited disorders, including some that affect the cardiovasc ular system. This approach consists of finding a DNA marker that coseg regates with the disorder and then using the tools of molecular biolog y to examine systematically the DNA in the vicinity of such a marker u ntil the gene is identified. In addition to the availability of precli nical diagnostic tests for individuals at risk, the identification of such genes might also provide the basis for targeted drug design. In t he longer term, with the emerging technologies for the delivery of gen es into cells, finding the genes that cause inherited disorders raises the possibility of eventual therapeutic intervention.