Genetic disorders and testing - hypotheticals *BT refs*

These types of tests are before you are even pregnant Missus S, there is no risk of harm to baby at all.

I didn't meant because of that ducky, what I meant was that before I ever got pregnant, I'd have wanted to and wanted to know, but my perspective changed. I wouldn't now because it wouldn't make a jot of difference to how I felt or how a pregnancy progressed. I just added the amnio part to show that I did have the testing done that was available, but wouldn't do it again

That's what I was getting at. Once upon a time I'd have wanted to know and would of had the screening/tests available. Pre and during pregnancy but I wouldn't have either now

If I have understood the question correctly, and based on my current status as childless, I would say that I would have the screening, and any other screening available, if it were pre-conception. I am starting to think about when would be a good time to start a family and being already in my mid-30s this is the kind of issue I will ponder. If pre-conception I were to discover that I and/or my OH were genetically at risk of passing on a serious condition to any potential child would we go ahead and TTC? It's thought-provoking and for me depends on the condition and quality of life that baby would have. I think there has to be an element of selflessness in any decision because the desire for a child may become overwhelming, but as I say, I make that statement based on my current childless situation, I may feel very differently if I were pregnant or already had a child. I certainly think it ought to be available though for women who wish to be screened.

I would have the screening just because anything we could be prepared for before hand in my opinion is worth doing. I think it should be opt-in though rather than general testing as some people would really rather not know and I think that should be their choice.

As an active TTC-er, I would (and will) take any tests that are offered to me, provided that they are risk free. I think that any form of assistance in terms of educating and preparing parents can only be beneficial.

I think its a difficult one for me. On the one hand I can't dispute that knowing you could pass this on could prepare you. However, even if you both carry the gene there is still no guarantee that you will have a baby with CF. I then wonder how much good the worrying would do you for an eventuality that may not actually happen.

I (along with my younger sis) were tested for CF as small children (sweat test?) as our older sis died from it, aged 1 hour. My parents obviously knew there was a chance of my sister and me of having CF, but chose to have us anyway.

Any type of screening never occured to be before or during my pregnancies. I had the 12 and 20 week scans, but declined the downs screening.

Now, after going through what i did with C, I'd refuse testing. I refused the abnormality testing with Henry too this time. I changed. I no longer cared if the baby was 'perfect'. I knew i could deal with anything as long as i got my baby to keep. Some may think that's irresponsible but if itd come to (and it kinda has with the whole cerebral palsy issue going on) I'd research and learn wht I needed to know when the time came. Knowing wouldn't make a shred of difference

Exactly this. I would have said yes to all testing prior to my losses. Once I'd had that experience, I no longer cared about the baby being perfect, as long as it wouold have a good quality of life, that was enough for me/us. We did discuss in this pregnancy whether we would have testing at the stage where you can have such things, but declined it all. having had the experience (which I know Missus S has had too) it can totally change your perspective on these things.

I think the key is the 'quality of life.'

CF quality of life is getting better and treatment means life expectancy is longer. However there are other conditions which are even more life-limiting. For me, at this stage in my life, there is a difference between an 'imperfect' baby, and one that has to suffer a great deal throughout its life.

I swing between saying I would and then saying I wouldn't.

I would because I'd prefer to know if there was a possibility that any future children might be born with the condition

But I also wouldn't because what if there was a possibility and even though my first born was okay, I'll spend the next pregnancy worrying about the possibility!

I would get tested. Not only for CF but anything that could help us take an informed decision, get the chance to learn more about anything that could impact the baby's quality of life, and how (and if) we could provide for the best life the littl'un could have.

This is surprisingly hard to answer. The sensible part of me says of course I would test. But in all honesty, I don't know if I would. Mainly bacause I would be scared to find out something that would affect how I felt about a child (at least until they arrived).

But in reality, I had a cousin who died young, from a genetic condition that took both parents to pass on (don't know what it was, I was also young at the time) so the reality is that my mum could carry that gene, and therefore so could I, so I will need to speak with my family and try to be tested if possible. It just seems a little...I'm not sure of the correct word...irresponsible maybe? to know there could be something and not check. But I wouldn't go 'looking' for loads of problems if there was no reason to suspect an issue.

Took me a while to read through everyone's responses and I think they are all quite interesting and informative. I was not aware that so much screening could be done beforehand and it is something that I think I would do if I was considering TTC. Out of interest FTLOMB, with screening could such disorders eventually be 'extinct'. Theoretically if everyone was screened, for example for CF, and then defective gene couples were offered alternatives (have I understood correctly that you could have selected eggs etc?) could the defective gene eventually be screened out?

I can see how this could move towards designer babies and then that's a whole different ethical minefield.

Hmm, there certainly has been eradication (or, at least, near eradication) of a common and particularly horrible genetic disorder in a particular population (Tay-Sachs disease in Ashkenazi Jews). The success was down to several factors: rich and educated population amenable to a variety of interventions (IVF/PIGD, termination), with the severity of disease providing a great, if not imperative, motivator for screening.

However, Tay-Sachs children are still born to other ethnic groups, typically those less able to access medical care and mostly opposed to interventions involving embryo destruction (in whatever form).

Should we try to eradicate Tay Sachs completely? I don't know that we could, nor do I know that we should....

Sickle cell disease is a dreadful genetic disorder, to be avoided if possible. However, mutations in the relevant gene are created anew over and over again. Even if we banned every single carrier of the bad gene from breeding - in theory, creating a global population free from the bad gene - the bad gene would pop up again pretty quickly. There are a couple of reasons for this. The gene is quite susceptible to mutation, so the good copies pretty quickly turn bad. But most importantly, carrying a single bad copy of the sickle cell gene is actually good for the person under certain environmental conditions. In the case of sickle cell, a person carrying one bad gene copy is far more resistant to malaria, which is a huge - unspeakably huge - survival advantage in certain parts of the world. This means people with a bad copy survive, reproduce an pass on the bad gene....unfortunately, it means some people are born with sickle cell disease. In evolutionary terms, this might be considered "collateral damage".

Could you get rid of the bad sickle cell gene? Probably not for very long. But would you even want to?

Cystic fibrosis has similar advantages for those who carry a single bad copy, such as resistance to cholera (you don't lose as much fluid) and resistance to TB (the bugs can't as easily colonise your ever-so-slightly-stickier-than-normal lung lining). That might not mean much to us in the UK now, but it probably kept us strong in the middle-late last millenia (where things like TB were massive killers). It's the most commonly touted reason for why the bad gene prevails (and at least one form of the bad gene is some 50,000 years old).

So, we simply don't know what some of these "bad" copies are doing in the normal course of our evolution. I'd hesitate to suggest that we should aggressively target the eradication of a disorder, because we likely don't know what effect that might have. But I don't believe we can do it anyway. Unfortunately, that means we have to accept that some children are going to be born with sometimes very serious genetic disorders. It becomes very uncomfortable for me to recognise that the cost of my desire to maintain variation and diversity will probably fall on the shoulders of someone far more vulnerable than I.

I didn't realise that was what the "advantage" of the CF gene was thought to be! It's certainly not as clear-cut as the malaria/sickle cell one though. Sickle cell is another disease which I would strongly consider pre-conception testing and PIGD for, if it were available, though neither of us are in an "at risk" group so it's not something I need to worry about personally.

For me, wanting to know and potentially avoid having a child with CF is not to do with creating a "designer" baby or trying to manipulate the gene pool. It's just about trying to avoid suffering for my child. Although treatment for CF has come on a long way, and survival into adulthood is now pretty much expected, you would still be committing your child to a lifetime of physiotherapy, medication and medical interventions. If it happened out of the blue then obviously I would deal with it, but if it could be avoided by embryo selection, then I'd do that. It may be considered selfish as I'd be doing it for the benefit of my child and our family rather than mankind though.

Exactly this. I'd be tested purely for the knowledge and preparation I could take up.

My thoughts exactly. I would definitely have the tests. Mr Erin has Marfan's Syndrome so l have already started to prepare myself that if we were to have children they would probably have it too as each parent with the condition has a 50% risk of passing on the genetic defect. But obviously there may be other genetic issues with either of us.

Erin, has he had tests? Marfan is really variable - some people have strong features, some are very mildly affected. Is he really tall?

Yes, he was diagnosed after tests a couple of years ago and see's a specialist each year. He has a lot of the symptoms -tall (6'3), slim, long arms / legs, poor circulation, curved spine, high palate, crowded teeth and heart issues. The aorta issue is why Mr Erin's Dad is having surgery in a couple of weeks. Mr Erin doesn't have any issues with his sternum but his brother and uncle's curve out.