• Question: i am doing a issue report on genetic screening for my AS level so what is your view on pre natal genetic screening for conditions such as cystic fibrosis?

    Asked by jacko212 to Anne, Carolyn, Joe, Mariana, Nick on 18 Mar 2010 in Categories: .
    • Photo: Nick Bradshaw

      Nick Bradshaw answered on 18 Mar 2010:

      My wife and I actually had a baby 18 months ago and our opinion was that if a screen told us that something was wrong which the doctors could fix – then we would want to know. If it was something that we couldn’t do anything about, then we would rather not have the test (particaulrly as some tests carry a risk to the baby).

      So for example – we wanted to know if our baby had spina bifinda (a developmental problem of the spine) beacuse doctors can operate on this in the womb or very soon after birth and we though it was in our baby’s interests for us to know as soon as possible. However we declined the test for Downes Syndrome as if our baby did have it then there would be nothing we could do about it, and the test does carry a (very small) risk to the baby, so really we didn’t see the point. (Our baby is fine and helathy by the way)

      So anyway, cystic fibrosis. It would depend what the test involved. However, if scientists had come up with a way of helping the baby in the womb or immediately after birth then I would be in favour of it. The other question of course is whether parents should have a test in order to decide whether to abort the baby if they have CF. Personally, I am against that as, while CF sufferers lead diffuclt lives, they at least still can live there lives. Others would disagree with me on that however.

      Sorry long answer!

    • Photo: Joseph Devlin

      Joseph Devlin answered on 18 Mar 2010:

      I think it’s an important area of research, particularly as genetically engineered therapies become effective. So if you could detect and treat an illness like CF in utero, that would be an amazingly good thing to do — although a bit in the future.

      In more current terms, genetic screening can be used with IVF to help select the embryo(s) with the best chance of survival and again, that makes a lot of sense to me.

    • Photo: Mariana Vargas

      Mariana Vargas answered on 18 Mar 2010:

      Hello, that’s a very hard question. People with cystic fibrosis today have a life expectancy of around forty years (although fifty years ago life expectancy was only five years!) and people who are affected by it can have troublesome symptoms throghout their life, that’s why parents who are both carriers of faulty genes can choose to have their embryos pre-screened for this condition, and only have those free of the condition implanted in the mother. It is good for people to have this choice as it would be them who have to deal with the effects of this disease for life and perhaps an early death of their son/daughter.
      However, with current advances it is posible that a cure would be found in the next few decades and babies born today with the condition may be able to live long and healthy lives. But this is not for sure. So one wonders if it’s best to let nature choose the embryo that will get fertilised or if it’s best to do this prescreening to help parents (who perhaps already have other affected children) choose.
      Current laws allow the parents to decide this themselves.

    • Photo: Carolyn McGettigan

      Carolyn McGettigan answered on 19 Mar 2010:

      This is a very sensitive subject, with lots of different sources of risk that have to be evaluated.

      First, screening tests for diseases are not 100% accurate. This applies to tests on the mother and father to see if they carry the abnormal gene causing CF, and to tests on the foetus. This means that, amongst all the mothers tested, some will receive test results to suggest their child has cystic fibrosis (CF) when the child is actually unaffected, and some will be told their child is unaffected when it actually has CF. These numbers are relatively small but will vary from test to test.

      Second, pre-natal screening for a genetic mutation disease like CF requires a sample of the foetal DNA. This usually requires an invasive procedure to collect foetal cells, like an injection into the mother’s womb to sample the amniotic fluid in which the baby is supported during gestation. This kind of procedure also involves risk to the baby, and may (in a small proportion of cases) lead to miscarriage.

      So, pre-natal screening might be accurate for most cases, but there is some room for error. Current research on pre-natal screening aims to develop tests that exhibit greater sensitivity and accuracy, and to find less invasive methods such as sampling foetal cells from the mother’s blood. It will be important for at-risk parents to be well-informed of these developments. I think whether or not the tests are taken should be treated on a case-by-case basis, as different parents will have different levels of risk to weigh up based on their circumstances. It is certainly critical that parents in the position of considering genetic screening receive the support they need, from people like genetic counsellors. It would be important to consider whether having the ‘knowledge’ of their child’s disease pre-natally would be of any benefit other than informing a decision to abort the foetus. This is particularly thorny in the case of CF where there is currently no available pre-natal treatment.

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