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Promise and perils of PGD

Watch an interview with Joyce Harper, Head of Department of Reproductive Health at UCL, about the current - and potential - applications of PGD.
So the wonderful thing about infertility treatment is that it has helped millions of couples worldwide have children. But what about if they carry a genetic abnormality? So we have patients that have things like cystic fibrosis or Beta thalassemia and they want to have a child who’s not got these diseases. So this is where pre-implantation genetic diagnosis comes in. It is a technique where we use IVF procedures. The couple go through IVF as normal and we generate the embryos in the lab and then we are going to biopsy these embryos. We are going to take one or two cells from these early embryos, do our genetic test for the disease that we are looking for like cystic fibrosis.
And then we can tell which embryos are free from the disease and we can transfer those embryos back into the woman’s womb so they start the pregnancy knowing that the embryos are free from the disease that they are carrying. So it is a great opportunity for couples carrying genetic disease to start that pregnancy knowing the embryo is free from the disease. When we started PGD in the early 90’s we really only looked for the one disease that the couple were carrying. Or if they had something wrong with their chromosomes we only look for that specific chromosome abnormality.
And even then it sometimes used to take two or three years to develop a test which was actually then quite specific for that couple. But as the technology has changed we are now using, at the moment DNA chips, and also moving onto sequencing, where really we apply the same tests to any couple, no matter what disorder they are coming in with so next generation sequencing, at the moment we are just as I said looking at the chromosomes, but within a few years we will be doing quite deep sequencing and we will be able to use this test to look at any genetic abnormality.
But it will also tell us a lot about the embryo that is not related to a specific disease. We will be able to look at characteristics such as predisposition to height predisposition to cancer genes, all sorts of interesting things which bring up a lot of ethical discussions. We want the new phone we want the new car, we want technology and it is going to happen. So ethically, I have some issues about a stage where we would do PGD for every embryo or where we would genetically modify our embryos. So this is something that with different professional groups, we have been debating and writing papers on. But I think it will happen no matter what objections an individual might have.
There are different rules and regulations in different countries of the world. So in the UK we are governed by the Human Fertilization and Embryology Authority, and we have strict regulations about what techniques we can and cannot offer to our patients. But in other countries they have different rules and there is also different availability of treatment. There are different costs of treatment. If we put fertility treatment in different countries in Google you will come up with all sorts of interesting things. You can go to Barbados and have sun, sea and fertility treatment. You can win IVF holidays in different countries. An ethical issue that comes up in PGD is that we can sex the embryos.
The techniques that we use now chances are we will know the sex of the embryo as well. If we use a DNA chip or a next generation sequencing for sure we will know the sex of the embryo. In the UK, and actually in Europe, it’s illegal to choose the sex of the embryo unless there is a medical reason. But there are clinics in other countries outside Europe that are doing this to a huge level. So there are clinics in Cyprus, Russia, all over the world that are doing sex selections. So this is where a couple decide that they want to have a child of a particular sex. And low and behold what sex do you think they normally want?
They normally want a boy. The trouble with having a girl, even in 2016 and onwards, is that a girl will cost money to educate and then when she gets married, in many cultures we have to give a dowry, and then what will happen is in most cultures she then leaves the family home and goes to the husband’s home. So there is no one to look after the parents older age. So even today, having a girl is not economic sense in many cultures. And it still happens in India and other countries where it is the birth of a girl everyone is very sad, when it is the birth of a boy everyone is having a party in the maternity ward.
So, PGD worldwide, especially in the developing world where this is more of a problem, people are selecting boys. And this has caused a massive problem in a number of countries, not just PGD but also other reasons why girl pregnancies are either aborted when they find the sex when the woman is already pregnant, or even worse when the children are born and the girls are either put up for adoption, and taken to an orphanage or even worse they are actually just left to die. So this does happen globally. In China, in India, we have apparently millions about 17 million more boys than girls in both of these countries.
And if you speak to people from China, for sure, they’ve just removed the single child policy and that is because in a lot of areas they just don’t have enough girls anymore to get married and to have a family. So actually it is really having a negative effect now on the population of those countries. And there is a fantastic novel called, ‘The First Century After Beatrice”, which is a sort of science fiction novel where a pill is given to a woman and then she can’t have any more girls, she can only have boys. And globally when it is done to such an extent it causes a massive economic population problem.
But we are there in some countries already, in some pockets of countries where we have a huge excess of males compared to females. So this needs a whole education of how we can move forward. But if we get to a stage where more people are reproducing by PGD because of the advantage that selecting your embryos with sequencing may have or even editing your embryos, we could really end up with a huge issue.

Science is forever moving forward. What was new a few years ago, is today taken for granted. New targets are set, and when these are reached, a new horizon of possibilities beckons.

This is true for PGD, which after 25 years now enable us to test for over 250 genetic abnormalities. And as we have seen, we can now already test for risk genes, and select the embryo with the best genetic chances.

Professor Joyce Harper was part of the original team that developed the technology of PGD in the early 1990, and she has worked in the field of embryology and IVF for almost three decades.

Here, she highlights how rapidly the technology is evolving in this field, with possible future applications. Some of these are worrying, and the question remains: whose responsibility is it to direct the progress of the science?

For your discussion: Joyce Harper describes a potential future where genetic testing will be more prevalent and where PGD is used not only to minimise disease-burden but to create a certain kind of child (for example, a boy). Do you think this is a real worry in some parts of the world? How close are we to such a future?

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