Knowing is half the battle: preconception screening

In a recently released report the UK Human Genetics Commission said there are “no specific social, ethical or legal principles” against preconception screening. If a couple may benefit from it, testing should be available so they can make informed choices. Information about this kind of testing should also be made widely available in the health system (and in school). The responses in the news have been along predictable lines, with critics warning that this is a modern version of eugenics or that it would lead to some people being stigmatized.

Preconception genetic testing checks whether a person is a carrier for a genetic condition. This affects reproductory decisions since two carriers (assuming they both carry recessive alleles) have a 1/4 risk of each child being born with the condition. The report notes that “there are good reasons why earlier testing is favoured over later testing, as it facilitates wider patient choice and improved access to information supporting reproductive decision-making.”  These options include couples deciding to remain childless, adopt a child, accept the chance of having an affected child, conceive naturally and use prenatal diagnosis to decide whether to terminate or continue the pregnancy, conceive using donated sperm or eggs, or use IVF with PGD to ensure the implanted embryo is unaffected. Without this knowledge they can at most discover the condition during pregnancy, substantially limiting their options.

The criticism that this is eugenics misses the point: the reason eugenics got a bad reputation is that it was something enforced from the government, based on bad science and intended for the good of an abstract community, not the family affected. The report instead builds its argument on two principles,

“(i) the principle that respect for reproductive autonomy implies that a range of reproductive options should be available (all other things being equal). This in turn implies that preconception genetic testing should be available as one such option and that it should be equally available to all those who may benefit from it; and (ii) the principle that, where there are reproductive options available, individuals should be supported in making informed choices.”

These principles are quite the opposite of outside coercion, actually putting individuals more in charge of their reproduction than before. Of course, actual implementations in health care systems might suffer from biases that need to be detected and reduced.

The fear that discovering one is the carrier of a “bad” allele will lead to stigmatization and becoming marriageable seems somewhat overblown.  Many people already know about their genetic defects and have good lives, and indeed children – knowing about a risk doesn’t mean people doesn’t take chances (especially if they are in love). The anguish of parents discovering that they are carriers by having a baby suffering an ailment is surely worse than discovering that you are a carrier due to a test.

If one wants to reduce human anxiety, the recommendations in the report  are very sensible because of the dramatic technological changes happening.

Right now the cost of genetic sequencing is plummeting. While the price for sequencing an entire individual genome is still in the hundreds to thousands of pounds, expectations are that within a few years prices are going to be down in the tens of pounds. And the cost of just testing for a few gene variants is going to be far smaller. This means that it will be very hard to prevent anybody who wants to find out whether they are a carrier of something nasty from taking a mail order genetics test or get their full genome sequenced. Interested people will be able to get the answer regardless of what the health system allows.

But dealing with the answer is something different than acquiring it. People rarely think about genetic risk. Getting understandable information, time for reflection, help handling the emotional aspects and learning about the reproductive options available – this is not going to be automatically available just because there is a test or sequencing. The report recommends ensuring that the testing be done in conjunction with access to genetic counsellors and health professionals with knowledge of the condition and its management. This is the sensible way to deal with the unsettling nature of genetic risk – not trying to keep people from learning they have it, learning about what it means and doing something based on this information.

Will widespread use of screening methods make sufferers of genetic conditions second class citizens? The evidence so far doesn’t bear it out. As the overall health of society has improved, so has also the treatment of medical minorities. Stigmatization is more often due to a lack of understanding of the condition: the spread of information envisioned in the report might actually counter much of the prejudices that exist.

Would a world where no children with cystic fibrosis were born be a better place? I think so, despite the amazing gains in lifespan and life quality enjoyed by people with the condition (for other genetic illnesses such as Tay-Sachs disease the outlook is far worse). The condition limits the life choices of people and impairs their welfare. Each individual born should be glad they were actually born (and we should be glad for another person in the world). But if we have a choice I think it is better to ensure that people come into being that have more potential lives in front of them than fewer. Preconception screening allows us to give this and the next generation more informed choices – that is why it matters.