Genetic Screening Now Lets Parents Pick the Healthiest Embryos
People using IVF can see which embryo is least likely to develop cancer and other diseases. But can protecting your child slip into playing God?
"At 18 months old, Aurea Yenmai Smigrodzki is inquisitive like any other toddler. She likes peanut butter, the beach, and mobile phones—or any toys that look like phones. She likes to copy her mum and dad, Thuy and Rafal, when they are using theirs. Aurea doesn’t know it yet, but her birth was very special: She is the world’s first PGT-P baby, meaning she is statistically less likely than the rest of us to develop a genetic disease or disorder throughout her life...
Rafal and Thuy were given the genetic profiles of five prospective embryos, and Aurea’s was the strongest candidate, because her embryo had the fewest recognizable genetic mutations that could go on to cause disease. “It was really a no-brainer,” says Rafal of the choice he and Thuy made to undergo the genetic screening process. “If you can do something good for your child, you want to do it, right? That’s why people take prenatal vitamins.”
All parents want their children to be healthy, but lots have reason to fear passing on something harmful. Our genes can predispose us to developing all kinds of diseases: diabetes, heart disease, cancers, and many more. With this in mind, one could be forgiven for assuming that Rafal or Thuy carried some inheritable condition and wanted to break the chain. But the reality, Rafal admits, is that he “simply knew that PGT-P existed,” and so he decided to give it a try.
Rafal is a neurologist and has an interest in pioneering technologies, referring to himself as a “techno-optimist.” He has even signed up to have his brain cryogenically stored when he dies, in the belief it will one day be resurrected, thoughts and spirit intact. In his eyes, genetic screening of embryos is nothing crazy or even special, it is simply the natural next step for humans to take. “It’s like the first time someone ever made a phone call—sure, it was a unique moment, but really it was just the beginning of something that now everybody does,” Rafal muses. “In 10 years’ time, this kind of polygenic testing will be completely non-controversial. People will be doing it as a matter of course.”
[ ] “People ask me if I’m trying to play God in choosing to do this,” Rafal adds, anticipating the next big question. He believes that “genetic selection is not playing God, it’s working as a mechanic on molecular machines that sometimes break and need to be fixed.”
Embryonic selection itself is nothing new. For around three decades, IVF clinicians have taken sperm and egg samples to grow into several embryos at once, before choosing the most promising-looking one for implantation in the uterus. Clinics already tend to screen against chromosomal abnormalities such as Down’s syndrome, but until recently the only other indicator they had to go by was the way one group of cells looked against the other—the selection was more or less arbitrary.
Companies such as Genomic Prediction are taking this process much further, giving parents the power to select the embryo they believe to have the best fighting chance of survival both in the womb and out in the world. At the time of writing, Genomic Prediction works with around 200 IVF clinics across six continents. For company cofounder Stephen Hsu, the idea behind preconception screening was no eureka moment, but something he and his peers developed gradually. “We kept pursuing the possibilities from a purely scientific interest,” he says. Over time sequencing has become cheaper and more accessible, and the bank of genetic data has become ever greater, which has provided the opportunity to easily apply machine learning programs to seek out patterns, Hsu explains.
. . .As Hsu indicates, the crucial difference with this technology is that it’s not just single mutations like cystic fibrosis or sickle cell anemia that the service makes its calculations on. The conditions embryos are screened for can be extremely complicated, involving thousands of genetic variants across different parts of the genome.
In late 2017, Hsu and his colleagues published a paper demonstrating how, using genomic data at scale, scientists could predict someone’s height to within an inch of accuracy using just their DNA.
The research group later used the same method to build genomic predictors for complex diseases such as hypothyroidism, types 1 and 2 diabetes, breast cancer, prostate cancer, testicular cancer, gallstones, glaucoma, gout, atrial fibrillation, high cholesterol, asthma, basal cell carcinoma, malignant melanoma, and heart attacks. This did not come without controversy. In fact, by mid-2020, the outrage among graduate students at Michigan State University was loud enough to force Hsu out of his position as vice president at the institution. Hsu believes that the opposition people felt to Genomic Prediction in the beginning was largely because people feel uneasy about the fact that genetics can seal our fate—that unfavorable traits can’t always be amended through hard work and determination. “People don’t want to believe that there’s some degree of hardwiring that can’t be overcome by good habits or good education,” he says.
“But the fear is misplaced: the ability to detect single gene mutations has been around for some time and nobody considers that ethically questionable, right? It’s just that now we can do it with more precision.”
. . .Like Rafal Smigrodzki, Hsu is confident that public disapproval will ease, and that one day soon embryonic selection against inheritable diseases will be considered the norm.
In his opinion, “we shouldn’t only use artificial ways to reproduce, but we should make use of the tools we have for IVF to ensure we have the best chance of making healthy babies.”
[ ] It’s completely changed the way people all over the world manage pregnancy,” says Rabinowitz."
Rachael Pells is the author of Genomics: How Genome Sequencing Will Change Our Lives. Find out more and order your copy of the book.
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