One day a doctor might hold off on prescribing you a drug until your genes get the once-over in a device made by Affymetrix. The Santa Clara company that pioneered the use of the gene chip -- a DNA-scanning system for genetic research -- is now the first to adapt such technology for the diagnosis of individual patients. Doctors will soon be able to order a test to find out whether patients have unusual gene variations that predict whether they’ll suffer bad reactions to certain drugs. The diagnostic chip can reveal whether patients clear drugs from their systems too quickly or too slowly. Too fast, and the normal dose is too low to do much good. Too slow, and the drug builds up in the bloodstream at potentially dangerous levels. The AmpliChip CYP450, developed by Roche for use on Affymetrix systems, is the first diagnostic test approved by the Food and Drug Administration that belongs to the class of gene-scanning tools called DNA microarrays. The FDA approval in January was a milestone that Robert Lipshutz had expected from the day he started work at Affymetrix in 1993, a year after the company started.
