Picking embryos with best health odds sparks new DNA debate

BOSTON • Dr Rafal Smigrodzki will not make a big deal of it, but some day, when his toddler daughter Aurea is old enough to understand, he plans to explain that she likely made medical history at the moment of her birth.

Aurea appears to be the first child born after a new type of DNA testing that gave her a "polygenic risk score". It is based on multiple common gene variations that could each have tiny effects. Together, they create higher or lower odds for many common diseases.

Her parents underwent fertility treatment in 2019 and had to choose which of four in-vitro fertilisation (IVF) embryos to implant. They turned to a young company called Genomic Prediction and picked the embryo given the best genetic odds of avoiding heart disease, diabetes and cancer in adulthood.

Dr Smigrodzki, a North Carolina neurologist with a doctorate in human genetics, argues that parents have a duty to give a child the healthiest possible start in life. "Part of that duty is to make sure to prevent disease - that's why we give vaccinations," he said. "And the polygenic testing is no different. It's just another way of preventing disease."

The choice was simple for him, but recent advances in the science of polygenic risk scoring raise issues so complex that The New England Journal Of Medicine in July published a special report on the problems with using it for embryo selection.

The paper points to a handful of companies in the United States and Europe that already are offering embryo risk scores for conditions including schizophrenia, breast cancer and diabetes.

"We need to talk about what sort of regulation we want to have in this space," said co-author Daniel Benjamin, an economist specialising in genetics - or "genoeconomist" - at University of California, Los Angeles.

Among the problems the journal article highlights - most genetic data is heavily Eurocentric at this point, so parents with other ancestry cannot benefit nearly as much. The science is so new that huge unknowns remain. And selection could exacerbate health disparities among races and classes.

The article also raises concerns that companies marketing embryo selection over-promise, using enticements of "healthy babies" when the scores are only probabilities, not guarantees - and when most differences among embryos are likely to be very small.

The issues are so complicated and new that the New England Journal article's 13 authors held differing views on how polygenic embryo scoring should be regulated, said co-first author Patrick Turley, a University of Southern California economist. But all agreed that "potential consumers need to understand what they're signing up for", he said.

He expects the demand for polygenic embryo scoring to rise as continued advances in DNA analysis bring down the price and improve the predictions. "There's obviously some demand for it already because we're seeing multiple companies springing up to offer it," he said.

Genomic Prediction, which lists almost two dozen clinics that offer its polygenic testing, charges US$400 (S$540) per embryo tested after a US$1,000 set-up fee. Competitors include Orchid, a start-up launched with backing from Silicon Valley stars including Ms Anne Wojcicki, founder of genomics company 23andMe.

Dr Denis Vaughan, a reproductive endocrinologist and director of clinical research at Boston IVF, says the large fertility clinic network has been discussing polygenic embryo scoring, but "we don't think it's ready for prime time". It should still be used mainly in a research setting, he said, and "it's being commercialised a little prematurely".

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