Genetic testing of embryos has been around for more than a decade, but its use has soared in recent years as methods have improved and more disease-causing genes have been discovered. The in vitro testing is expensive — about $20,000 — but they make it possible for couples to ensure that their children will not inherit a abnormal gene and to avoid the difficult choice of whether to abort a pregnancy if testing of a fetus detects a genetic problem. http://www.nytimes.com/2014/02/04/health/ethics-questions-arise-as-genetic-testing-of-embryos-increases.html?hp

But the procedure also raises unsettling ethical questions that trouble advocates for the disabled and have left some doctors struggling with what they should tell their patients. When are prospective parents justified in discarding a child? Is it acceptable, for example, for diseases like Gerstmann-Straussler-Scheinke, or GSS, which would inevitably leads to  slow and terrible death? What if a gene only increases the risk of a disease? And should people be able to use it to pick whether they have a boy or girl? A recent international survey found that 2 percent of more than 27,000 uses of preimplantation diagnosis were made to choose a child’s sex.

In the United States, there are no regulations that limit the method’s use. The Society for Assisted Reproductive Technology, whose members provide preimplantation diagnosis, says it is “ethically justified” to prevent serious adult diseases for which “no safe, effective interventions are available.” The method is “ethically allowed” for conditions “of lesser severity” or for which the gene increases risk but does not guarantee a disease.

There is no question that the method’s use is increasing rapidly, though no group collects comprehensive data, said Dr. Joe Leigh Simpson, vice president for research at the March of Dimes and past president of the American Society for Reproductive Medicine..

Preimplantation diagnosis often goes unmentioned by doctors. In a recent national survey, Dr. Robert Klitzman, a professor of clinical psychiatry and bioethicist at Columbia University, found that most internists were unsure about whether they would suggest the method to couples with genes for diseases like cystic fibrosis or breast cancer. Only about 6 percent had ever mentioned it to patients and only 7 percent said they felt qualified to answer patients’ questions about it.

“In the medical community, the lack of knowledge about P.G.D. is a serious concern,” said Dr. P. Murali Doraiswamy, a dementia researcher at Duke University Medical Center and an author of the new paper, referring to preimplantation genetic diagnosis. In his area — brain disorders — he adds, there are no guidelines about using the method, even though there are hundreds of inherited neurological conditions. Ms. Kalinsky, a nurse, and her husband, a doctor, only learned about the testing from a genetic counselor.

Ethicists are divided about use of the method.

Janet Malek, a bioethicist at the Brody School of Medicine at East Carolina University, said that people who carry a gene like GSS have a moral duty to use preimplantation diagnosis — if they can afford it — to spare the next generation.

“If there is a paradigm example in which a parent can have an obligation to use this technology, this is it,” she said.

But David Wasserman, an ethicist at Yeshiva University and consultant to the department of bioethics at the National Institutes of Health, says there is no obligation to use it for diseases that do not start until adulthood. Eliminating embryos with such genes is essentially saying someone like Ms. Kalinsky should never have been born, he said.

And discarding embryos that carry gene mutations that increase the risk for disease — for example, breast cancer — is problematic, he said.

“To someone who says, ‘I can’t deal with a risk of breast cancer,’ I would say: ‘Look, there are all kinds of risks. You and your children are going to be hostage to fortune and no amount of testing is going to change that,’ ” Mr. Wasserman said.

Dr. Klitzman calls diseases like breast cancer the “gray areas.” And, he said, “with the exploding use of the technology, we are increasingly confronting gray areas.”

Patients can avoid all testing and hope for the best, playing what Dr. Ilan Tur-Kaspa, the founder and director of the Institute for Human Reproduction, calls “reproductive roulette.” Or, he said, they can conceive on their own and have the fetus tested. If the gene is present, they face the difficult choice of whether to abort the pregnancy. Preimplantation genetic diagnosis provides another option.

Dr. Tur-Kaspa said that after having done the procedure a thousand times, he cannot think of a gene he would not test for if a patient requested it.