Cross Post: If you can screen for brown eyes, you should be able to edit out genetic disease

Not everyone’s choice of scarf. Shutterstock

It has long been known that cognitive diversity is important to collective performance. Diverse groups are more productive, more innovative and better at solving complex problems than less diverse groups. And recent research suggests that cognitive diversity also drives scientific progress.

Such research has direct implications for how we regulate reproductive technologies. Late last year, the London Sperm Bank was criticised for its decision to ban sperm donors who suffer from minor neurological disorders, including dyslexia and Asperger’s syndrome.

Selection against these conditions may be problematic because it could reduce valuable forms of cognitive diversity. People with dyslexia and Asperger’s syndrome see problems from unique perspectives and use different methods to solve problems.

The fact that the London Sperm Bank could implement such a policy highlights the great inconsistency in how the selection for and against different inherited conditions is regulated.

Gamete screening (GS) – the screening of sperm and egg donors based on their features – is widely unregulated. Not only can it be used to select against mild disabilities such as dyslexia, but it can also be used to select for non-disease traits such as eye colour and height. Companies such as Elite Egg Donors, allow you to choose between various donors based on a wide variety of factors including education, weight, and ethnicity. While GS is still relatively imprecise, it is becoming more powerful.

Only candidate. Shutterstock

In 2013, personal genomics company 23andMe received a patent to a technology called “gamete donor selection based on genetic calculations”. This technology uses DNA tests from sperm recipients and donors to calculate the likelihood of embryos being created with particular traits. Someone wanting to increase the chance of having a child with green eyes, a low predisposition to smoking, and a low risk of colon cancer, for example, could use 23andMe’s technology to identify donors which gave them the highest probability of achieving these traits.

Pre-implantation genetic diagnosis (PGD) is the process of creating a range of embryos through IVF, performing genetic tests on them and then selectively implanting one with particular genes. It is far more widely regulated than gamete screening. In the UK, regulations limit its use to selecting against “serious” inherited conditions. However, what is regarded as serious is considered on a case-by-case basis. Each proposed use of PGD is examined individually. Those that are risky or frivolous can be rejected.

There is no reason why such a system could not work for gamete screening. If a sperm bank or fertility clinic wants to offer gamete screening for or against particular conditions, it should also be assessed on an individual basis. This would provide a system to protect the public interest, and prevent the loss of valuable forms of diversity.

Such a regulatory system should also be implemented for new gene editing technologies, once they are shown to be safe. While these technologies are still in in their infancy, they are developing rapidly. In a decade, it is likely that somatic gene editing – or gene therapy – will be used to treat common cancers. We will be eating gene edited crops and animals. At some point, gene editing technologies will be widespread, cheap and precise.

Many jurisdictions, including the UK, explicitly outlaw using gene editing technologies to influence the inheritance of a condition. Reproductive gene editing is treated as an absolute moral limit that is never permissible, no matter how great the benefits that may accrue from it.

What’s the difference?

It seems bizarre that the method we use to select for or against an inherited condition makes such a significant difference to its legal status. A woman wanting to have a green-eyed child with blond hair, a low predisposition to obesity and high intelligence, for example, is legally able to use gamete selection to find a donor. Yet a couple who wants to use gene editing technology to save their child from developing Tay Sachs disease – a degenerative disease which results in death by age three – cannot do so, even if it is the only way they can avoid it.

When compared to gamete screening, gene editing may seem like a radical way of transforming our features. We have never used technologies to change our genetic code before. However, our code is constantly changing anyway. The only difference between intentional gene edits and natural mutations, is that the former are directional rather than random. Whether this is good or bad depends on which direction we choose to go. Moving towards a world with less disease and suffering is surely desirable.

We need a coordinated approach to the regulation of inheritance; and PGD should serve as the model. Each proposed use of gamete selection and gene editing should be assessed on a case-by-case basis. When therapies are shown to be safe and effective, they should be added to a list of approved conditions. I don’t believe dyslexia, or Asperger’s syndrome should be on that list, and sperm banks should not be able to ban donors with these conditions.

 

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2 Responses to Cross Post: If you can screen for brown eyes, you should be able to edit out genetic disease

  • Paul Treanor says:

    This claim is very badly formulated:

    Moving towards a world with less disease and suffering is surely desirable.

    What exactly is the suffering, and what or who is causing it? That is essential information for judgements on genetic modification of humans to minimise suffering. Possibly Dr. Gyngell means suffering caused by disease, but even that is ambiguous. The really problematic issues arise, when we need to consider suffering caused by another person. Gay men, for instance, often cause distress to orthodox-conservative Christians. Does that mean that the state should prohibit transmission of a ‘gay gene’, if one is found? Whose suffering counts? It is easy to think of such controversial examples, but ethicists are embarrassed by them, and prefer to limit themselves to simple medical cases. That makes it easier for the general public to empathise, but it is not a good basis for moral judgement.

  • Chris Gyngell says:

    Thanks for your interest Paul. That sentence is meant to be read as a conjunction: a world with less disease and (as a result) less suffering. Not sure I follow the criticism re homosexuality. I agree that the medical case for using gene editing is the most compelling.

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