Sex-selective abortion is the first consequence of such technology to already become a reality, as reflected by the changing gender ratio in China and India. While tests for chromosomal abnormalities aren't intended for the sole purpose
of determining gender, the presence of a Y-chromosome is hard to
miss when you're looking at DNA -- parents are typically given the opportunity to
opt out from
receiving this information.
The House of Representatives
declined to outlaw sex-selective abortion
in the U.S., but a particular fear here may in fact stem from the ability to screen for disease and disability. In a 2004 survey of American opinion
surrounding genetic testing from the Genetics and Public Policy Center, the most commonly cited
societal implication of concern to the respondents was the potential of discrimination against the disabled. The possibility of a sex-ratio imbalance was much lower down
the list.
It may be a slippery slope, but it will be hard to argue that this newest information won't be safely in the green zone. Of the five chromosomal
abnormalities detected by the test, two -- trisomy 18, also known as Edwards syndrome, and trisomy 13, also known as Patau syndrome -- have extremely low
survival rates. Half of the fetuses with Edwards syndrome that are carried to term do not survive beyond the first week of life. Eighty percent of infants
with Patau syndrome don't make it past their first year. Early testing allows parents more time to be prepared for this tragic outcome.
Down syndrome (trisomy 21) and Turner syndrome (monosomy X), on the other hand, are not at all death sentences. Although characterized by a variety of
physical and mental challenges, advocacy groups have gone a long way toward helping people
understand that these conditions do not prevent people from having long and fulfilling lives. Some have expressed outrage
over the Affordable Care Act's requirement of insurers to cover prenatal genetic testing as "preventative care" for women, making the fair, if mostly
semantic point that the only way you can "prevent" Down syndrome is through abortion. Concern over bias against babies with Down syndrome is
understandable. But since it is by far the most common of chromosomal abnormalities, with the incidence rate rising to 1 in 100 births for mothers who get
pregnant at age 40, it's already something that parents are aware of as a potential risk. With that in mind, it's difficult to argue against the pragmatism of granting them access to as much information as possible.
The fifth abnormality, an extra X-chromosome in males, is accompanied physically by what are better described as characteristics than symptoms, and though
it also associated with a degree of language impairment, many men go through life not even knowing that they have the condition. Awareness, in this case,
will only ensure that children get early intervention where before they may never have been diagnosed.
And while a blood test can let parents know, early and accurately, if
their baby's DNA contains any of these chromosomal abnormalities, it is
unable to tell them the
clinical consequences of their genetic makeup -- with the more
wide-ranging conditions, there's no way of knowing how a specific child
will be affected.
Ethical issues may just be beside the point here, though. Natera doesn't see its test as a potentially abortion-informing agent, because unlike amniocentesis or chorionic villus sampling (CVS), it is unable to give a definitive diagnosis. Instead, it's a way of safely screening for the possibility of these diagnoses so that
woman know whether they should undergo the more invasive tests (which could, theoretically, inform abortions). The accuracy of those tests comes with the risk of miscarriage, and the only other option for women before the advent of blood screening was a safe but unreliable hormone test.
