To the biopharmaceutical industry, these differences represent possible drug targets. Polymorphisms are changes in DNA that do not cause disease. However, they may be associated with disorders and therefore could serve as markers for locating disease-causing genes. This type of study could present market opportunities for a range of diagnostic, therapeutic and preventive applications. These applications can be either diagnostic or therapeutic.
Scientists know the location and mechanism of certain genes.
For example, the p53 gene is a tumor suppressor and is altered in more than half of all cancers. Affymetrix has developed a p53 chip to help researchers determine the mechanism of the gene in mutated form as well as the potential effectiveness of therapies. There is also an HIV chip to help scientists study drug resistance to the AIDS virus, which mutates repeatedly and can be fatal when drugs lose their effectiveness. In the future, he says, clinical drug trial participants may be chosen on the basis of their genetic profile, and individual therapies will be selected so that optimal treatment can be prescribed based on that profile. Further down the road, Nelson says, we might see these chips used frequently to diagnose patients at the DNA level for certain diseases.