Wednesday, April 04, 2007

Rectal exams and the son-of-a-bitch gene

Do you ever wonder how medical students practice prostate exams?--Prostate cancer doesn’t get nearly as much attention as, say breast cancer, for reasons sociological, not medical. It is the second greatest killer of men after lung cancer. The American Cancer Society estimates that 232,000 men will be diagnosed with the disease this year and 27,000 will die of it. Thanks in some part to PSA testing, the death rate is declining rapidly, a drop of 32.5 percent in 10 years. If it is caught early, 100 percent of men are alive five years later; if it has metastasized, only 34 percent are still alive.

In a really important study, scientists have found a genetic basis for the disease that has all kinds of ramifications. They also found more evidence that the politically correct attack on the notion of race as a biological attribute is hogwash.

The researchers found seven genetic risk factors, all bunched close together on chromosome 8 that predict a man’s probability of developing prostate cancer. Five are newly discovered; two were known before and the experiment, done at USC, the National Cancer Institute and a company in Iceland, confirmed them. That of course does not mean it’s all genetic; other risk factors like environment also play a role, but if you have the genes you know to be extra cautious and get tested regularly. The role the genes play in this still is unknown. The study is reported in Nature Genetics.

An interesting aspect, however, is it may explain the disparity between blacks and whites in prostate statistics. A black man is twice as likely to die of prostate cancer than a white man and the reason now appears to be genetic. For several decades some scientists have been attacking the whole biological definition of race, claiming it has no scientific meaning. This, of course, is politics, not science, and is nonsense. The list of ailments that have a racial component is long and impossible to ignore and with prostate cancer, there is now a demonstrable genetic explanation: blacks tend to have more of those genes.

And the answer to the question above is: on themselves. And good practice it is. Haven’t you always wanted to stick something up a classmate’s ass?

Oh, on second thought, maybe we should look for the cute and cuddly gene--James Watson, Nobel laureate and codiscoverer of the helix structure of DNA, thought it might be fun to have his DNA scanned using a new technology that would make it possible for all of us peons to knows what lurks in our genes. The technology comes from 454 Life Sciences, a company that hopes to bring the cost of genome scanning down to manageable levels from the several hundred thousand dollars it costs now. They asked Watson to be the first to be scanned and he agreed. Now it seems he is chickening out. According to David Ewing Duncan at Technology Review, Watson first asked the company to delete any results for genes associated with Alzheimer’s disease. Now he is worried that publication of the rest of his genome will violate his privacy and that of his sons. And since there is now a firm genetic basis for certain behavioral traits, they might be able to show genes in his scans for arrogance and temper. Craig Venter, who sequenced the human genome, who may also have the arrogance and temper genes, appears less concerned and is still planning on release his.

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