David Goldstein

Parental demand for “designer babies” screened to lack faulty genes will grow dramatically over the next decade, with new discoveries about the influence of DNA on health, a leading geneticist has predicted.

As science learns more about the genetic roots of disease, couples will increasingly seek DNA tests on their embryos when starting a family, according to David Goldstein, of Duke University in North Carolina.

By 2020, researchers will have discovered many more genetic variations that substantially raise the risk of common conditions, such as diabetes, heart disease and psychiatric disorders, and it will be possible to detect these in embryos, he said. This will feed much wider interest in embryo screening, which is currently used by only a few dozen couples each year, and encourage fresh controversy over the ethics of designer babies.

Writing in the journal Nature, Dr Goldstein said that his expectations about the speed at which genetics would advance had led him to make a “confident but uncomfortable” prediction about the future of screening. “The identification of major risk factors for disease is bound to substantially increase interest in embryonic and other screening programmes,” he said.

“Society has largely already accepted this principle for mutations that lead inevitably to serious health conditions. Will it be so accommodating of those who want to screen out embryos that carry, say, a twentyfold increased risk of a serious but unspecified neuropsychiatric disease?”

He told The Times that he was personally uncertain about the right answer, but that it was an essential question for society to debate now. “I don’t have a fixed view, and I can see both sides pretty well,” he said. “We should think about an appropriate dividing line. Most people are in favour of allowing this when a disease is severe, but are more uncomfortable with marginal disease risks. It’s something we are going to have to think hard about.”

Embryo screening involves a process called pre-implantation genetic diagnosis (PGD). Embryos are created by in-vitro fertilisation and grown to the eight-cell stage, at which point one or two cells are removed. Scientists then examine the DNA of these cells for defects, and only normal embryos are replaced in the womb.

Although PGD was developed two decades ago, it is currently applicable only to a limited range of serious and rare conditions such as cystic fibrosis, which couples know they risk passing on to their children.

The technique is also occasionally used to conceive a child suitable to donate umbilical cord blood to a sick sibling. Raj and Shahana Hashmi were the first British couple to win permission to do this, to help their son Zain who suffers from beta-thalassaemia, though the procedure failed.

Dr Goldstein, however, expects its scope to widen significantly over the next ten years, as science starts to unlock more of the genetic factors that contribute to common conditions such as heart disease, type 2 diabetes, autism, schizophrenia and epilepsy.

It had been thought that much of the genetic influence over these diseases lay in common DNA variations with reasonably small effects, which would not be amenable to embryo screening. Recent research, however, has suggested that rarer variants with much larger effects on risk are actually more important. New technology for reading DNA will soon allow scientists to find many more of these variants with large effects, and also to screen for them in embryos.

Dr Goldstein’s forecast for 2020 is one of 18 prepared by scientists for Nature, in which they set out the advances and challenges they anticipate in their fields for the next decade. Other predictions include a suggestion by Peter Norvig, the director of research at Google, that most internet searches will start with spoken rather than typed commands. He also expects experiments to begin into monitoring individuals’ brain signals to search the web.

David Relman, of the Veterans Affairs Palo Alto Health Care System, in California, and Jeremy Nicholson, of Imperial College London, look forward to an improved understanding of the trillions of microbes that populate the human body and influence health.

In astronomy, Adam Burrows, of the US National Research Council, highlights the nature of dark matter, which makes up much of the Universe but has not been directly detected, as the most pressing question.

Gary Pisano, of Harvard Business School, raises the prospect that a major Chinese multinational drug company will emerge, and that pharmaceutical companies that invest in marketing at the expense of research will be “doomed to failure”.