"This is a potentially disruptive technology, one that can change the social structure and order," says David Adamson, president-elect of the American Society for Reproductive Medicine and director of a private fertility clinic in northern California. "It will move us toward a preventive approach to medicine and could change our approach to reproduction." Tests are already available for genetic variants associated with a thousand conditions, including deadly childhood illnesses and adult-onset cancers, and more genes associated with disease risk are being discovered every day. Any such gene could be a target of PGD. Santiago Munné, director of Reprogenetics, a genetics laboratory headquartered in Livingston, NJ, says his lab has tested embryos for more than 150 diseases or risk genes--most recently for a gene variant known as BRCA1, which raises the risk of breast cancer. Little data yet exists on the use of preimplantation genetic tests. But late last year, the Genetics and Public Policy Center at Johns Hopkins University released a report in the journal Fertility and Sterility presenting some of the first statistics on the use of PGD nationwide. "We wanted to get a sense of how much PGD was being done, and why," says Susannah Baruch, the center's director of reproductive genetics and lead author of the report. "Without solid data, it's difficult to analyze outcomes for PGD babies or to help prospective parents make decisions about whether to pursue PGD." The researchers surveyed all the fertility clinics in the United States that offer IVF, asking questions about the types of preimplantation tests they administer, how they make ethical decisions, and how they think testing should be regulated. About half of those clinics responded. According to the survey, screening for chromosomal abnormalities that can lead to implantation failure or miscarriage, or for disorders linked to chromosome duplication or deletion (such as Down's syndrome), represents two-thirds of all PGD testing. Tests for genetic diseases such as cystic fibrosis account for another 12 percent. Forty-three percent of clinics said they had received requests for PGD that they felt raised ethical questions; most of these were from parents who wanted to select the sex of a child for nonmedical reasons. The survey found that this use of PGD is fairly common: almost one in ten tests was for nonmedical sex selection, a service offered by 42 percent of clinics. Since it is the only PGD test that is often administered without medical justification, sex selection is especially contentious; some fertility clinics will not offer it, and some ethicists say that nonmedical sex selection opens the door to other types of nonmedical testing. But other people argue that biological enhancement through genetic screening is not so alarming, or at least not so different from other types of advantages that are already enjoyed by a certain privileged sector of the population. "I don't think testing for freckles or blond hair or musical aptitude is a morally bad thing to do," says Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania. "I think parents will want to do it, so I think this will expand rapidly." |
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The Fingerprints of Embryos
05/23/2008
Comments
lkrndu on 03/30/2007 at 5:14 AM
14
But. That is exactly what we will have here, ultimately, with pre-implantation genetic screening, and with genetic testing and pre-selection writ large. Medical testing for gross and severe and fatal defects - Down's syndrome, for example - is the secure corner about which no reasonable person could offer objections. But to insure offspring with nicer dimples?
The ethical tests fail. And will fail, in the onslaught of narcissistic self-fulfillment implicit in now having available - what to call them? - selective services.
Of course there is no bright line separating the extremes. This reader can offer two rough and frail observations, however.
1. If the number of people I have known personally who have suffered or died of genetically-related diseases had been subjected to pre-implantation tests, before they were 'conceived', my world - the world - would be far less interesting. And far less populous. I would go farther: it would be insufferably boring.
That would be a bad thing.
2. Dogs do it. The strongest, smartest, most adaptable are the mutts, while the sleekest, most conforming-to-human fantasy are also the weakest, most freighted with displasias, back problems, nervous disorders, stomachs that get contorted...and all the rest of the sorts of defects that are reinforced through artificial selection that favors the reproducing arbitrarily valued but physiologically and medically irrelevant characteristics.
That's a good thing.
And we should well note and follow that example.
Bob Tyson
karlhedderich on 03/30/2007 at 11:45 AM
9
I agree that when humans start trying to breed organisms for specific traits we often don't account for the whole system. An example of this is tomato breeding/engineering where as the tomatoes have become more uniform in size and color they have lost some of their flavor. The engineers failed to select for all of the traits that were important in a commercial setting. This is a major argument against genetic engineering (or any technology that significantly alters reproductive diversity), how can people determine what traits are "good" traits and how could we select for all of them. This objection to engineering your children seems to be an engineering problem that while significant it isn't intractable. All scientists would have to do is develop the understanding needed so that engineers could make well informed changes. People also argue that suffering leads to greater diversity in the world and while this is true I fail to see how it is a good thing.
gabrielg01 on 03/30/2007 at 4:58 PM
287
Genetic engineering promises to stop such molecular accidents before the person even comes into existence. The technology would work at the sperm or egg level, not at the embryo level.
As for the moral arguments - what would you tell your kid suffering from Huntington's disease? (or other disease - pick your favorite): "You know, we had the technology to prevent this, and give you a healthy life, but we thought that interfering with nature would be immoral..." If this kind of moral argument holds, then we can deny medical treatment for any other disease based on the principle "let nature run its course".
MITBeta on 03/30/2007 at 9:32 AM
21
karlhedderich on 03/30/2007 at 11:47 AM
9
mightybob on 04/01/2007 at 2:38 PM
9
swordfishdata on 04/02/2007 at 8:01 PM
7
Phineas on 04/01/2007 at 2:41 PM
44
Evolution has done a magnificent job but the temptation to alter ourselves will prove too strong. Why propagate bad genes when you have choice? Animal research is applicable to the human animal.The laudable goal will be to improve our lot. Polio today; Huntington's tomorrow.
There are serious potential pitfalls but Folks will fiddle.