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Test For Prostate Cancer Gene Soon To Be Available
Tiger4 writes "CNN reports on a simple test to determine the presence of genes linked to Prostate Cancer. These five genes, if present, can increase the risk of prostate cancer up to nine times. 'More than 25,000 American men will die from prostate cancer this year. But prostate cancer can be treated successfully if the disease is caught early. A blood test that can detect whether a man is at high risk for developing prostate cancer is on the horizon. The study was published in the February 28, 2008, issue of the New England Journal of Medicine.' It turns out the company actually wants to test saliva, making the test significantly easier and more convenient. Compare this to the tests available for BRCA, the so called Breast Cancer genes. Finding you have the gene can be devastating, but knowing well in advance of developing cancer allows many more options to be considered."
Just remember that these are not genes (or, more correctly - alleles) that determine, in an absolute manner, whether you'll get the cancer or not (unlike, say in the case of the mutant gene for Cystic Fibrosis). They are variants that, when present alone or in combination increase the risk. It's a bit like with insurance - when you're a twenty-something, living in a large city, and want to insure a sports car, you'll pay a greater premium than a middle aged small-town father insuring a minivan, because the risk that you'll have an accident is several times higher. But that doesn't mean that all urban twenty-somethings in sports car will crash (in fact, most of them won't), and it doesn't mean that the minivan driving fathers never crash. It't the same with the association of genetic variants with cancer - there is no causative relationship - there is only an increase in risk. Which means that the test can be informative (to a varying degree), but is never definitive (unless it's a simple Mendelian trait, like CF, which the common cancers are not). Read this informative post on The Evolution & Medicine Review for a sobering view on genetic association in complex traits. Also, if you follow the link to the company page you'll see (in the News section) that the main paper (in NEJM) reporting the association was a study done on the Swedish population, and it's by no means certain, that it'll hold for other population backgrounds. All this doesn't mean that it's worthless, just an advice to take it with a grain of salt.
There isn't.
There are several problems with gene therapy, or, in your example, somatic gene therapy, as we call this technique. To summarize them: The problem is to "do it right". Granted, some cells are easier to target with specific virii, and some erroneous genes are easier to displace than others. But there's always an error margin in such a therapy, there always will be side-effects. And when talking about modifying genes of multicellular organisms, the most common side-effect is this: cancer. You will at some point of the therapy introduce dis-regulation of certain genes and thus you will increase the risk of cancer.
Gene therapy is not ready yet for prime time, the benefits don't outweigh the faults we introduce (some extreme cases of genetic disorders are possible exceptions).
Well, that's why some disease genes (like the one responsible for sickle-cell anemia) do exist at all: They provide for some positive side-effects.
If medically indicated, I'd have not much problems with that. But ...
The negative aspects far outweigh the benefits if you just change your genes for the sake of it.
And, remember: Gene therapy sounds great in the media because scientists need funding.
Disclosure:
IAAMB (molecular biologist)
And masturbate a lot. http://news.bbc.co.uk/1/hi/health/3072021.stm