Monday, October 22, 2007

Pharmacogenomics Rising

Just recently released, LabCorp will study the role of polymoprhisms in cytochrome p450 2D6 and women's response to breast cancer. Which is good news for physicians like myself who would gladly use this test if their were some good data. Unfortunately, some think it is ready right now for prime-time....

Which leads me to the next topic. In the November edition of the American Journal of Human Genetics there is a systematic analysis of something called Variants of Uncertain Significance. You see, the problem that DTC testing companies don't want to tell you is that sometimes an answer only confuses things. More importantly, these things called VUSs require significant follow up. You have to double check databases and see if the genetic changes found in yourself are also found in a significant amount of those tested. And if those tested have manifested disease. In BRCA it is breast or ovarian cancer. But what happens when you pay for testing and come up with a VUS? Who translates the data? A form? A phone call?

So what is the outcome of this study? It seems that VUS are more likely to have problems if they were located in splicing sites, in the protein coding regions, or in the highly conserved areas of the gene....Makes some sense. But, you will not know the answer until you have enough patients...Which means continuing follow up....Not exactly the most scalable solution.

Lastly, Dr Bettinger comments on the ancestry article I commented on earlier.

The Sherpa Says: Would we take the tests if we knew that it may not give us an answer.......or if it gave us an answer we weren't ready to find out. What if we weren't prepared to handle what we found out? That's the role of the genetic counselor. They are there to protect us from ourselves......Or help us find what we are looking for...

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