Personalized medicine is coming. What does that mean? It means that our genes will determine what type of medical treatment we get. We know, in any disease, that some people respond favorably to therapy while others do not. We assume that this is partially due to our genes. Some studies have shown correlations between the genes that a patient has and their response to specific medications.



One example is new study that will look at the interaction between a patient's genes and treatment with the blood thinning drug, warfarin. Over two million Americans that are at risk of stroke currently take this drug to prevent blood clotting. The problem is that patients all need different amounts to keep their blood at the right clotting potential. Too much drug can lead to excessive bleeding because the blood is too thin. Too little drug and the blood gets too thick, meaning it can clot easily and lead to stroke. Currently doctors determine these doses by trial and error, monitoring patients very closely until they find the right amount. The new study will follow 1,000 at-risk stroke patients after genetic fingerprinting to see if a patient's unique genes can predict their optimal dose.

This is the goal of personalized medicine, not just for warfarin, but for all drugs and non-drug therapies. Sounds like a great idea, right? There would be no more guesswork for the doctors; a higher probability of success for the therapeutics; and less patients going on drugs unnecessarily.

How Genetic Fingerprinting Works

Genetic fingerprinting works by determining what specific stretches of DNA are unique to any given person. Humans have about 30,000 genes (give or take a few thousand) and each of these genes are made up of thousands of individual bases, or links, that are joined up in a long chain. There are four different kinds of links and the order in which they are joined acts as a code to determine your genes. The vast majority of these links are identical in everyone with only a very small percentage of links differing from person to person. However, these differences are mostly in the same place across people. To get a genetic fingerprint, researchers don't need to look at all of your links in all of your genes. They only need to look at the points that tend to be different, a million or so out of billions of links.

This technology has only been around a few years and we are still improving it at a very rapid rate. Currently it costs about $1,000 dollars per person to do the fingerprinting and that figure will likely fall dramatically within a few years. Still, considering that your genes don't change throughout life, a one time cost of $1,000 to get ?genotyped' is not outrageous and will likely be available to the general public in a very short time, at least from a technological viewpoint. Public policy needs come first.

What are the Ethical Implications?

This technology has incredible promise for medical science, but also carries incredible burden for medical ethics. Some of the issues we will face as a society are these:

If you are determined to have genes that put you at a dramatically increased risk for disease in your adult years would you want to know? Would you want to know that information about your kids? If there were treatment options or lifestyle choices you could make that would minimize your risk you might think very differently about this question than if there were no treatments.

Who should have access to your genetic information? You? Your doctor? Your insurance company? Insurance companies today base their rates on average risk factors across a population. If genes can accurately predict disease risk then should insurance rates be personalized as well? If this were the case, it is likely that some people would be uninsurable because the risk would be too high.

What about in-utero genotyping? Should doctors perform genotyping on fetuses before they are even born? What if this would avoid early life complications for some children with risk of disorders? This will be a huge ethical debate.

This technology is at our doorstep. And it is only the beginning of ethical issues. Genetic finger printing simply provides information about the genes you are naturally born with. What will happen if we also develop the genetic engineering technology to alter ?bad genes'? Again, you may think very differently about this question if you are correcting your child's genes to prevent an inevitable pre-adult death than you would about choosing their eye color. But where will we draw the line? There is bound to be a large gray area.

For one view of this scenario, rent the movie GATACA, starring Ethan Hawke and Jude Law. It is about a future where society has implemented this technology. You will have to decide whether it is fiction or foresight.

Copyright (c) 2007 The Brain Code LLC