Should prospective parents seek information about gene variants that increase the risk their children will develop diseases as adults? Should physicians provide that information?

Some bioethicists believe that such pre-birth testing is wrong, arguing that the information could stigmatize kids or lead parents to terminate pregnancies of genetically at-risk fetuses. Children, they contend, have a right to an "open future" unburdened by the knowledge of their genetic predispositions for adult onset illnesses.

Consider the situation of Amanda and Bradley Kalinsky, as reported on the front page of The New York Times in February. Amanda Kalinsky tested positive for the gene that produces Gerstmann-Straussler-Scheinker (GSS) disease, a form of early onset dementia. Several family members, including her father, had already succumbed to the sickness. When she found out that she was a carrier, she initially vowed never to have children.

But then Amanda and her husband learned that they could use pre-implantation genetic diagnosis of their embryos to avoid passing the GSS gene to their kids. Fertility clinic specialists induced her to produce several eggs that were removed and then fertilized with her husband's sperm. The resulting embryos were tested for the gene, and only those that did not have it were implanted in her womb.

The happy result is that the Kalinskys are the parents of three children-3-year-old twins, Ava and Cole, and 9-month-old Tatum-who have been spared the prospect of suffering the disease that is likely to kill their mother. The cost for the first round of in vitro and testing was about $20,000, which the Kalinskys paid out of pocket. "I would travel that road a million times over if I had to," Amanda told the Times, "because in the end I was given the privilege of being their mother."

In the Times article, the Yeshiva University bioethicist David Wasserman argued that discarding the GSS-gene embryos is akin to concluding that people like Amanda Kalinsky should have never been born. But decisions about who should be born ought not to be placed in the hands of ethicists or physicians; they should be left up to the people whose lives and values are actually on the line.

For Kalinsky, the prospect of passing on her GSS gene was frightening enough that she initially ruled out reproducing. Pre-implantation genetic diagnosis enabled her and her husband to have children that they wouldn't have otherwise. In either scenario, the child with the GSS gene was not going to be born; this way, there are three new humans on the planet.

The Kalinskys were focusing on a single gene. But now a new, much more comprehensive whole-genome screening test is enabling physicians to identify disease risks that parents might not have any reason to suspect, such as genes increasing the possibility of breast cancer or Alzheimer's disease. The new test sequences a fetus's genome based on DNA it sheds into its mother's bloodstream. So researchers can now reveal genetic predispositions ranging from trivial characteristics like eye color and propensity to baldness to the risk of cancer.

Is it ethical for physicians to sequence a fetus's genome and then tell parents what the genetic screening test uncovers? Yes, argues Ignatia B. Van den Veyver of Baylor College in the January 2014 issue of Prenatal Diagnosis. Among other arguments, Van den Veyver wonders "whether we infringe autonomy by shielding information that may allow parents and young adults to make decisions about their future that take into consideration all aspects of their current or future health," adding: "It is not well established that not providing this predictive information is the only direction to preserve the right to an open future."

Indeed not. Apparently, what some bioethicists mean by "open future" is one in which both parents and children are kept ignorant of the ways their complement of genes may expose them to medical risks.

Prenatal whole-genome sequencing will also provide parents with information about their prospective child's genetic susceptibility to illnesses like lung cancer, arteriosclerosis, and diabetes. Armed with such genomic knowledge, mothers and fathers could make sure that they don't smoke around their kid and later explain why it's a really bad idea for him or her to take up a tobacco habit. Warned in advance about their child's heightened risk of diabetes, parents could devise a diet and exercise regimen aimed at preventing its onset.

The American Medical Association (AMA) got it right when it offered ethical guidance to its members on prenatal genetic screening way back in 1994. "If prenatal diagnosis is performed, the principle of patient autonomy requires that all medically relevant information generated from fetal tests be passed along to the parent or parents," the AMA declared. "While the physician should generally discourage requests for information about benign genetic traits, the physician may not ethically refuse to pass along any requested information in his or her possession. The final decision as to what information is deemed appropriate for disclosure can only fall to the parents, informed by the facts and recommendations presented to them by their physician."

More recently, in the January 16 New England Journal of Medicine, Ilana Yurkiewicz of Harvard Medical School, Lisa Soleymani Lehmann of Brigham and Women's Hospital, and Bruce Korf of the University of Alabama at Birmingham argue that it is ethical to provide parents with prenatal whole-genome sequencing information, because it is "a basic right of reproductive choice and parental autonomy; people may choose when, with whom, and how to reproduce, and they have the right to data that may inform these decisions." The trio also notes that women in the United States do not have to provide a reason for obtaining an abortion, so it is "difficult to justify restricting abortion in the case of a well-defined reason, such as genetic disease."

The researchers reject the notion that genetic ignorance is somehow liberating. "Instead of limiting a child's potential future, knowledge of genetic risks can offer a greater opportunity to inform possibilities for a good life," they point out.

And that's the essential point. Whatever some bioethicists might believe, autonomy is never enhanced by ignorance.