Designer babies? Scientists can read nearly the entire genome of an embryo
MyOme, a California-based company, claims to be able to decipher nearly all of the DNA code of a days-old embryo created through in vitro fertilization (IVF).
Given the limited amount of genetic material available for analysis, this is a very tough task. Beating the odds, the researchers were able to accomplish this breakthrough by sequencing both parents' DNA and "reconstructing" an embryo's genome using that data.
This could suggest that it may be feasible to estimate risk for diseases that could arise decades in the future just by looking at a days-old IVF-created embryo.
Sequencing the human genome
It should be emphasized that such genetic risk prediction is currently being tested in adults and is sometimes supplied clinically. Applying the technology to IVF embryos has sparked controversy among scientists who argue that the bioethics of genetically engineered children could be incredibly dangerous, but that hasn’t stopped the technology from quickly progressing.
According to the study published in Nature Medicine, the MyOme team, led by co-founders and scientists Matthew Rabinowitz and Akash Kumar, claimed to have achieved the scores by sequencing the genomes of ten pairs of parents who had already undergone IVF and had children.
The researchers used data gathered during the IVF process, as 110 embryos from the couples had undergone limited genetic testing at the time. Using statistical and population genomics tools, the team was able to anticipate a major amount of the embryo's DNA by combining these data with the more complete parental genome sequences. The researchers were also able to see whether their reconstruction was accurate by checking the genome of couples' babies.
When the researchers compared that to the reconstructed genome for the embryo from which the child originated, they saw that, essentially, it was a match. At least 96 percent of the reconstructed genome aligned with the inherited gene variations in the corresponding infant in a 3-day-old embryo, and at least 98 percent in a 5-day-old embryo.
The researchers were also able to calculate polygenic risk scores for 12 diseases, including breast cancer, coronary artery disease, and type 2 diabetes, for the embryos.
This could change everything
“We’re talking about providing information on risks that people care about—heart disease, cancer, autoimmune disease,” co-founder Akash Kumar explained in a Science article. Kumar is also a pediatric medical geneticist, who still sees patients. As a doctor, he frequently sees frustrated parents who want to prevent passing on to their children a high risk of diseases that run in their families.
The technology could possibly assist there. One day, science may even allow parents to select embryos based on their IQ and risk of certain diseases. However, it's far too early to say anything as such a new method will be fraught with controversies and obstacles.
Moreover, there are many limitations, including the fact that the study is based on DNA from individuals with predominantly European ancestry, which means it would be less accurate in other groups. It's also unknown whether scores based on adult DNA and health data apply to embryos, partly because the environment can greatly influence outcomes.
The researchers state that they are aware of the shortcomings and criticism. However, they'll continue with other studies, as they see a lot of potential.