Doctors prescribing medicines use way too much trial and error to match drugs and doses. If the first prescription doesn't work, they try a different drug, change the dosage or start looking for interactions with other drugs the patient is taking. Success is counted when the side effects are not too gruesome and the patient improves.
Pharmacogenomics, combining pharmaceutical knowledge with our increasing understanding of the human genome, analyzes a patient's genotype to find prescriptions that maximize effectiveness and minimize side effects. It can also reduce adverse drug reactions, a major cause of healthcare mortality.
Ten years ago, genetic testing like this was strictly a laboratory affair. Today, you can do it at home with products like Genelex's mail order DNA test kits that screen for drug reactions, identify disease tendencies and even check ancestry and paternity. Tests cost anywhere from $250 for an identity profile to $1,590 for a Platinum Package.
The Genelex web site is split into branches "For the Public" and "For Medical Professionals." It's the public side that suggests DNA testing as a nice gift ... maybe for Fathers Day or Valentines Day, I guess.