Prenatal Screening: is too much knowledge unethical?


Image from uclahealth.org

Over the past decade a wave of prenatal medical research has given people a plethora of tests that will teach them more about their unborn child.  Until recently these tests have been constrained to only testing for life-threatening diseases.  Now, however, the gates are beginning to open for prenatal screening, and many non-invasive procedures that will allow for early diagnosis of chromosomal abnormalities—such as down syndrome—will soon be available on the market.

Testing for Down syndrome is nothing too new in the scientific world; two previous tests have been around for a few years already.  Amniocentesis is a test that involves taking a blood sample from a pregnant woman’s belly and sampling cells from the fluid swathed in her fetus.  This test involves only a 1 percent risk of a miscarriage, however, its flaw is that it is performed between 15-20 weeks into pregnancy, right around the deadline to abort a fetus in many U.S. states.  The other type of test, chronic villus sampling, involves sampling tissues from the placenta.  It can be performed earlier than amniocentesis, but since it is more invasive, it carries more risk to the fetus.

The new type of test can be performed about 10 weeks into pregnancy, and simply involves a blood sample.  A pregnant mother’s blood contains DNA from broken down fetal cells.  From this fetal DNA signs of down syndrome—an extra copy of chromosome 21—as well as other chromosomal oddities.  The new test also reports lower error rates.  Only .1 percent of cases turn up as false positive, much better than the 5 percent when compared to the older, more invasive tests.

Even more intricate than these screens for chromosomal abnormalities is the new ability for scientists to determine a fetus’s genome—its genetic make-up—from a sample of the mother and father’s blood.  While there are a few variant sites where scientists were unable to make predictions, the sites where they were able to predict reported 98 percent accuracy when taken from an 18.5 week old fetus.  The percentage remained high, at 95 percent accurate, for a fetus tested earlier—at 8.2 weeks.  (In order to test for accuracy the scientists ran their predicted fetal genome against one collected from the blood of the child’s cord after birth.)  While not perfected, this type of prenatal screening could be a harbinger for the near future, where parents would be able to know much, if not all, of their kids genetic make-up before the first trimester.

Along with prenatal screening, new procedures that would alter the mitochondria of embryos, thereby saving those children from inheriting dangerous mitochondrial diseases, have been Okayed to begin clinical testing in the UK.  There are two procedures that can do this, but both involve taking DNA from an egg with damaged mitochondria and transferring it to another woman’s egg that’s been stripped of its nucleus.  The procedure has yet to be tried on humans, but research is beginning to ensure that clinical trials would be safe to perform.

All of these prenatal studies and procedures are enormous advances for the scientific world, but they are rolling heads and causing some outcry for those concerned with the ethical implications. The number one concern is a that the ability to test for Down syndrome as early as 10 weeks into gestation may cause a rise in abortions.

Being able to predict a fetus’s genome at an early period is pregnancy is another factor that many worry will lead to more, and unnecessary abortions.  Researchers have admitted that they don’t quite know exactly how to interpret the variations they are able to predict and the genome and they wish to stress that difference doesn’t always mean defected.  The worry here is that many parents will test the fetus to decide about terminating the pregnancy.  If the genome looks odd it may lead to an unnecessary termination, one in which the child may have been born with no complications.  Another worry is the growing list of things that prenatal tests are allowed to detect.  First, it was only life-threatening diseases.  Now Down syndrome and other chromosomal abnormalities have been added, and British parents have been approved to test for cancer genes like BRCA.  Who knows what else will be added to the list; fetuses with abnormalities such as albinism and autism could soon be considered as biologically defunct.

Finally, the possibility of being able to prevent mitochondrial disease is something that should receive very little ethical discussion.  However, when the procedure for performing such a miracle involves the concept of having three biological parents, people begin to talk.  More than that, the procedure to prevent mitochondrial disease opens the door to other genetic manipulation of embryos.  This means that other inherited genetic diseases, such as cystic fibrosis and Duchenne muscle dystrophy, may be able to be prevented through the same type of procedure.  This also means, however, that other gene-editing procedures could be proposed, and if not carefully watched, carried out.

I for one back all these scientific advances 100 percent.  I believe that they are serving a great purpose and are letting the parents know, and prepare, for any complications their child may have.  Some of these tests may lead to more abortions, but I believe they will also lead to happier children, since the parents will be able prepare themselves for a child that may have some handicaps.  The only thing that concerns me is the new gene-editing procedures, and this is mainly because my grasp on this knowledge is slim at best.  In my mind, this ability could end up in some warped person’s mind and before you know it, we’re in some awful sci-fi world where a Utilitarianistic government makes everyone’s child look the same.  I don’t even know if that’s biologically possible, however, and a good chunk of me believes it is not.

For more information on how down syndrome can be detected through an early blood test:http://www.newscientist.com/article/dn21887-pregnancy-blood-test-can-identify-downs-syndrome.html

For more information on gene-editing for mitochondrial repairs:http://blogs.nature.com/news/2012/06/bioethics-board-backs-embryo-alteration-for-mitochondrial-disease.html

For more information on fetal genome from parental DNA:http://www.nature.com/news/fetal-genome-deduced-from-parental-dna-1.10797

For information on how placental tests can help reduce high-risk pregnancies:http://phys.org/news94707572.html

Advertisements

Comments

  1. Definitely believe that which you stated.
    Your favorite justification appeared to be on the web the easiest thing to be aware of.
    I say to you, I certainly get annoyed while people consider
    worries that they plainly do not know about. You managed to hit the nail upon the
    top and also defined out the whole thing without having side-effects , people could
    take a signal. Will likely be back to get more.
    Thanks

Tell the Truth

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: