Tuesday, 19 July 2011
Friday, 8 July 2011
Undergoing a genetic test can be a blurry game of statistics. The results may provide an estimate of your disease risk, but certainties are few and far between. For Huntington’s disease the numbers are painfully simple. The gene has a high penetrance so, without further medical advances, if you’ve got the gene then you’ll get the disease.
I spoke to Angela, whose mother has Huntington’s, as did her mother before her. Angela blogs about her experiences and was kind enough to answer my questions about genetic testing and trying for a baby with Huntington’s in the family.
How did you decide whether to test for the HD gene?
I found out about HD being in the family when I was 16 or so. From the second I found out, I never wanted to know whether I carried the gene. I couldn’t see what good would come with it, but literally one day something changed inside me and all of a sudden I wanted to know. It wasn’t for one reason specifically, it was everything. I was starting to settle down – I’d met my husband, I’d started my career, I’d bought a house... Everything was falling into place and I just wanted to know whether or not I carried the disease. The change was so sudden and so complete, it was not a difficult decision. But I did sit on it for a year before I approached anyone about arranging a test so that I was sure that it was what I wanted.
How did you feel when you found out you have the gene?
When we walked out of the clinic, I was devastated and could barely hold myself up. I felt utterly defeated and I just could not imagine how life would continue. But it did. I was back at work the next day, we started planning our future, a big holiday, our wedding, our house together, our plans for children… I started reading lots of websites trying to find answers. I got hooked in with research projects at the hospital and through the HDA. I did a few fundraising events for the HDA. I wrote my blog and met new people. I threw myself back into our lives and our future, and each day, it got easier. There were bad days for a long while but not really anymore. Now, I think sometimes we do push ourselves maybe more than we had before in case we don’t have as long as other couples but generally we just get on with things. And other than the struggles we have had with starting our family, we have a good life. We are happy. And I don’t see it as being inevitable that I will get the disease even though I carry the gene. I am ever hopeful for a cure, that’s why I do everything I can to raise awareness via interviews and the blog, and take part in research projects.
Can you understand people who don’t want to find out?
I can totally understand. That was me for a long time. People need to work out their own routes and what works best for one person may not be the answer for someone else.
What about trying for children?
We chatted through all the options. Preimplantation genetic diagnosis (PGD) IVF offered us the route to have a child that was genetically related to both of us, without passing on the risk of HD. We both wanted to protect our children and our future descendants from a disease that can have such a devastating effect on health and family lives. PGD IVF works for one fifth of couples and we hoped to be one of the lucky ones.
PDG is often blithely referred to as the answer to genetic disease, but your experience has not been straightforward.
We tried PGD IVF twice. It didn’t work for us. My body was excellent at producing numerous eggs but they just didn’t cope well with the IVF process. We’d start off with almost 20 eggs and one by one, they’d fall by the wayside, struggling to fertilise, to develop or to live through the biopsy. At the end of both cycles, we had one egg left that was HD-free and suitable for transfer although for both cycles. However, both of these eggs were poor quality and did not become a pregnancy.
Talking to the embryologist at our first clinic, and our doctors at the next clinic, my eggs just weren’t responding as they should. There was nothing they could do to boost their quality, and considering how poorly they had responded, we were lucky to have got as far as the transfer on both cycles. One of our doctors at the first clinic said we should just continue with the PGD, but we needed something different.
We were acutely aware that I wasn’t getting any younger and that HD may shorten how much time we have. Egg donation offered us new hope. Keeping me out of the initial process meant no risk of HD, better quality eggs, and a 50/50 chance of success. Yes, it would have been lovely to have been genetically related to our children but this way I still get to be involved almost from the very beginning. Genetics didn’t seem to matter anymore.
It may become routine in the future for the entire DNA sequence of every newborn baby to be determined. What do you think we should do with the information about HD status?
I would hope that it could be kept for the child to decide – after all they might not want their parents to know or they might not want to know themselves. I guess if it could affect their health before they were 18 years old and something could be done to help, they could find out when they were younger.
Do you think PDG IVF should be restricted to diseases such as HD that are serious, due to a single gene and have high penetrance (ie if you’ve got the gene you get the disease)? Or should it become more widely available in cases where having the gene does not mean the disease is certain?
I don’t think anyone can make that decision except the people involved themselves. All the options should be made available to people so they can make their own choices. But I do think that egg/sperm/embryo donation should be more widely discussed and encouraged - our first clinic was very dismissive of egg donation and advised us against going down this route. But it gives people a chance to have their own child and minimise the risk of genetic diseases, with a much higher chance of success.
Would you want to have your own DNA sequenced to learn about other disease susceptibilities?
I don’t know. It would depend on what support was available once I had the sequence. If there were ways we could prevent diseases occurring or research programmes to get involved in then I can see there are advantages of finding out.
What are your hopes for the future?
I hope for a cure for HD. I hope for a happy and healthy life with my family. I hope our children will understand the decisions that we made on their behalves, and I hope they too will lead happy and healthy lives, free from HD.
On 14th February of this year Angela announced on her blog that the egg donation had succeeded and she was pregnant. Two days later she wrote:
We can look at each and say "We've stopped it. We've stopped Huntington's." And that thought alone is so powerful it consumes me. Our children, their children, their children, their children, their children... Descendants who we will never meet, but people whose lives won't be affected by Huntington's.
Many congratulations Angela!