A team of scientists at the University of Washington has cracked the entire code of a human fetus using only a sample of blood from its mother and a saliva smear from its father.
The technology is a significant step toward standard comprehensive testing of babies in the womb for genetic defects — those that mark serious disorders as well as those indicating risk for such diseases as alcoholism and obesity. And it potentially provides a window into non-medical heritable traits, such as hair and eye color, athletic prowess and IQ.
Rather than saving lives, pro-lifers see this test as an enhanced “search and destroy” diagnostic tool that exponentially expands the genetic information available on unborn babies — so that parents may have up to 3,500 genetic possibilities to weigh into a decision about whether or not to have an abortion.
Key to the new test is that it is non-invasive. The researchers took free-floating DNA of a fetus from the mother’s bloodstream and DNA from the father’s saliva and puzzled it together into a genetic picture of their 18-week-old unborn baby boy.
Comparing their own laboratory DNA map and a sample of the baby’s actual DNA taken after birth, they concluded in their study, published last month in Science Translational Medicine, that they had accurately spotted 39 of 44 de novo mutations, spelling mistakes in the genetic code.
These mutations have been linked to a wide array of diseases, from Alzheimer’s and autism to cancer, multiple sclerosis and schizophrenia. Environmental toxins are demonstrated to produce many types of mutations, and others are “spontaneous.” They continue to occur throughout life.
But a mutation for a disease is no guarantee a person will get it. Indeed, according to the latest research from the University of Washington’s Genome Sciences Department, most people are healthy walking mutants, carrying all sorts of subtle and even rare genetic predispositions to disease.
Even so, prenatal testing is developing at rocket pace. Since the 1980s, doctors have used chorionic villus sampling (CVS) and amniocentesis to diagnose genetic diseases such as Tay-Sachs and Down syndrome. Both tests invade the womb for samples of fetal genetic material, and they carry risks of infection and miscarriage. Amniocentesis can also actually cause the birth defect of clubbed feet.
Recently, at least three firms in California — Sequinom, Verinata and Ariosa — began offering non-invasive blood tests for Trisomy disorders, including Down syndrome. Multiplicom, a Belgium-based start-up company, entered the race late, and in June received a $260,000 grant to develop non-invasive prenatal testing. Two other companies are finishing trials of tests, and four of them are battling over patent rights.
But the test described by the Washington scientists could render the contest obsolete. Dr. Jay Shendure, the lead scientist, told London’s Telegraph: “This work opens up the possibility that we will be able to scan the whole genome of the fetus for more than 3,000 single-gene disorders through a single, non-invasive test.”
Another researcher on the team, Jacob Kitzman, added: “The improved resolution is like going from being able to see that two books are stuck together to being able to notice one word misspelled on a page.”
“I think we have a perfect storm brewing,” said Mark Bradford, president of the newly formed Jerome Lejeune Society (USA), a group that supports research, care and advocacy for Down syndrome and other genetic intelligence disabilities (see related story on page B6).
First, he said, the new blood testing removes the “fear factor” of risks associated with invasive testing, so more women will take the tests. And the results of that information are almost certainly going to expand the genetic “grounds” for abortion. Already, 93% of unborn babies who receive a positive test for Down syndrome are aborted. There have also been documented abortions for medically correctable disorders like cleft palate. And in the field of in vitro fertilization medicine, parents now routinely screen and discard embryos for genetic predispositions to disease, including breast cancer.
Thirdly, said Bradford, “The insurance companies are sure to become a factor, especially in light of recent court rulings in so-called wrongful birth cases.” This spring a jury awarded a Portland, Ore., couple $2.9 million because of the false negative provided by their prenatal testing. They argued that had the test been accurate, they would have aborted their 4-year-old daughter, who has Down syndrome. In the wake of that case, another couple is suing Kaiser Permanente for $6.25 million because their child was born with a rare genetic disorder called Charge syndrome — after prenatal tests had reassured them their baby was healthy. HMOs, insurers and even employers are going to be mindful of the potential cost associated with any disability that arises — even in the long term — if it could have been tested for prior to birth.
Threat of Coercion
Finally, there is the factor of coercion in pregnancy care. A New England Journal of Medicine June editorial discusses the tangled issue. It cites a 2007 survey of 229 obstetricians and 126 health lawyers in which 51% were “highly likely” to use courts to force a patient to undergo an unwanted caesarean section.
If half of those polled would use judicial authority to force an invasive surgery, it is easy to imagine support for forced non-invasive prenatal testing. Indeed, academics have already openly argued for forced prenatal testing and even abortion of babies with disabilities. In 2000, in the Journal of Medical Ethics, ethicist Henrikka Clarkeburn argued, “When parents are at risk of having a child whose life would be worse than non-existence, the parents have a duty to use prenatal testing and a duty to terminate an affected pregnancy.”
There seems to be no shortage of people in academic circles who are willing to determine which people’s lives are worse than non-existence, said Bradford.
“It’s a shame,” he added, “because there is very promising research and therapy for improving the quality of life of people with genetic disabilities.” Other research is looking at ways to prevent genetic disease.
“Some people think we already have a cure for Down syndrome and genetic diseases,” said Bradford, “and the cure is abortion.”
In terms of genetic testing, he added: “I’m afraid our worst dreams in the past have now become our reality.”
“While there might be some legitimate purpose to do this test simply for parents to be prepared for their special-needs children, for the most part, this is just a further slide down the eugenics slope,” said the Family Research Council’s David Prentice. “It’s simply another reason for selecting against young human beings and ending their lives prematurely.”
Celeste McGovern writes from Aboyne, Scotland.