How do scientists gather pharmacogenetic information?
Many pharmacogenetic findings are based on knowledge of biochemical pathways within cells. For example, scientists already knew a lot about the enzymes that break down the anticancer drug irinotecan when its toxic effects in certain patients came to light. This knowledge allowed researchers to rapidly pinpoint a genetic variant of one of these enzymes as the cause of the dangerous reaction. Scientists have developed a genetic test for this variant so that doctors can adjust the dosage for those at risk for serious side effects. Pharmacogenetic advances can also come from studies that accompany clinical drug trials. After obtaining permission from participants, some pharmaceutical companies collect DNA samples from people in clinical trials. Scientists then analyze the samples together with results of the clinical trial to identify genetic variations that correlate with a drug’s effectiveness or toxicity. Pharmacogenetic researchers have already identified many genes whose variations af
