Feb 20, 2023 05:01 PM
https://aeon.co/essays/embryo-risk-scree...ical-risks
INTRO: 'As long as it’s healthy!’ Up until now, this cliché was merely a generic – if somewhat ominous – way for expecting parents and their loved ones to talk about their future children. But what if that outcome was not merely an expression of wishful thinking, but something that parents could control?
Imagine a fertility doctor examining the embryos that could develop into your children, providing you with a menu. One has a heightened risk for schizophrenia but a very low risk for cancer; another has relatively low risks for these diseases but a three-fold increased risk for Alzheimer’s disease; and a third has roughly average risks for all of these diseases. Oh, and the first two are boys, while the third is a girl.
While this may sound like a science-fiction movie, several private companies have begun selling services that resemble this scenario. Such companies cater to couples undergoing in vitro fertilisation (IVF), offering to generate a genetic risk profile for each of their frozen, days-old embryos.
It’s estimated that more than 100 families have already taken these tests, and some resulting babies have been announced. But is it really possible to offer such a ‘menu’ in a way that provides meaningful, scientifically valid information?
This question has been the focus of our work as geneticists in the past few years. To the extent that the answer is yes, it raises an even more challenging question: should this be allowed?
To better consider these questions, we’ll review some key arguments for and against this kind of risk profiling – called ‘polygenic embryo screening’, or PES. (Terminology in this new field is not fixed, and the procedure is also sometimes called ‘preimplantation genetic testing for polygenic diseases’, or PGT-P.) We will attempt to clarify which arguments are relevant and convincing, and which require further study.
We will also consider this technology in the context of the historical evils of eugenics. Since the word eugenics is too often used in a manner that sheds more heat than light in discussions of genetic technologies, we will first lay out what is known (and not yet known), before engaging with the most inflammatory aspects of the debate.
Despite ample initial scepticism, recent science has demonstrated the potential utility of profiling human embryos for disease risk. Importantly, if these profiles are used to select the ‘healthiest’ embryo from a given IVF cycle, the child to be born is expected to have better health than a randomly selected sibling embryo.
However, unbridled enthusiasm would be misguided: these bright predictions might only be fulfilled under certain conditions, and there is a risk that consumers using these services will be misled about their benefits. Further, widespread implementation of embryo screening will not only complicate IVF clinical procedures, it could also have social and psychological effects that reverberate far beyond the clinic... (MORE - details)
INTRO: 'As long as it’s healthy!’ Up until now, this cliché was merely a generic – if somewhat ominous – way for expecting parents and their loved ones to talk about their future children. But what if that outcome was not merely an expression of wishful thinking, but something that parents could control?
Imagine a fertility doctor examining the embryos that could develop into your children, providing you with a menu. One has a heightened risk for schizophrenia but a very low risk for cancer; another has relatively low risks for these diseases but a three-fold increased risk for Alzheimer’s disease; and a third has roughly average risks for all of these diseases. Oh, and the first two are boys, while the third is a girl.
While this may sound like a science-fiction movie, several private companies have begun selling services that resemble this scenario. Such companies cater to couples undergoing in vitro fertilisation (IVF), offering to generate a genetic risk profile for each of their frozen, days-old embryos.
It’s estimated that more than 100 families have already taken these tests, and some resulting babies have been announced. But is it really possible to offer such a ‘menu’ in a way that provides meaningful, scientifically valid information?
This question has been the focus of our work as geneticists in the past few years. To the extent that the answer is yes, it raises an even more challenging question: should this be allowed?
To better consider these questions, we’ll review some key arguments for and against this kind of risk profiling – called ‘polygenic embryo screening’, or PES. (Terminology in this new field is not fixed, and the procedure is also sometimes called ‘preimplantation genetic testing for polygenic diseases’, or PGT-P.) We will attempt to clarify which arguments are relevant and convincing, and which require further study.
We will also consider this technology in the context of the historical evils of eugenics. Since the word eugenics is too often used in a manner that sheds more heat than light in discussions of genetic technologies, we will first lay out what is known (and not yet known), before engaging with the most inflammatory aspects of the debate.
Despite ample initial scepticism, recent science has demonstrated the potential utility of profiling human embryos for disease risk. Importantly, if these profiles are used to select the ‘healthiest’ embryo from a given IVF cycle, the child to be born is expected to have better health than a randomly selected sibling embryo.
However, unbridled enthusiasm would be misguided: these bright predictions might only be fulfilled under certain conditions, and there is a risk that consumers using these services will be misled about their benefits. Further, widespread implementation of embryo screening will not only complicate IVF clinical procedures, it could also have social and psychological effects that reverberate far beyond the clinic... (MORE - details)