I am informed by Genomic Prediction's CEO that the company does genetic testing for ~200 IVF clinics on 6 continents. The overall scale of activity is increasing rapidly and also covers more traditional testing such as PGT-A (testing for aneuploidy or chromosomal normality) and testing for monogenic conditions, PGT-M. Here, PGT = Preimplantation Genetic Testing (standard terminology in IVF).
I believe that polygenic screening, or PGT-P, will become very common in the near future. It is natural for parents to want as much information as possible to select the embryo that will become their child, and all of these types of testing can be performed simultaneously by GP using the same standard cell biopsy. Currently ~60% of all IVF embryos produced in the US (millions per year, worldwide) undergo some kind of genetic testing.
Polygenic Embryo Screening: comments on Carmi et al. and Visscher et al. (discussion of the NEJM paper described in the Bloomberg article).
Picking Embryos With Best Health Odds Sparks New DNA Debate
By Carey Goldberg
Rafal Smigrodzki won’t make a big deal of it, but someday, 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’s 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 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.
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, and most do their best. “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 dramatic 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.
‘Urgent’ Debate
The paper points to a handful of companies in the U.S. and Europe that already are offering embryo risk scores for conditions including schizophrenia, breast cancer and diabetes. It calls for an “urgent society-wide conversation.”
“We need to talk about what sort of regulation we want to have in this space,” said co-author Daniel Benjamin, an economist specializing in genetics -- or “genoeconomist” -- at UCLA.
Unlike the distant prospect of CRISPR-edited designer babies,“this is happening, and it is now,” he said. Many claims by companies that offer DNA-based eating or fitness advice are “basically bunk,” he added, “but this is real. The benefits are real, and the risks are real.”
Among the problems the journal article highlights: Most genetic data is heavily Eurocentric at this point, so parents with other ancestry can’t 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.
...I have thought this outcome inevitable since laboratory methods became advanced enough to obtain an accurate and inexpensive human genotype from a sample equivalent to the DNA in a few cells (2012 blog post). The information obtained can now be used to predict characteristics of the individual, with applications in assisted reproduction, health science, and even criminal forensics (Othram, Inc.).
Related:
First Baby Born from a Polygenically Screened Embryo (video panel)
Embryo Screening for Polygenic Disease Risk: Recent Advances and Ethical Considerations (Genes 2021 Special Issue)
Carey Goldberg is Boston bureau chief for Bloomberg. She appears in this recent WBUR On Point episode with Kathryn Paige Harden:
Compare to this 2013 "Genius Babies" episode of On Point in which I appeared.
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