I am not a scientist. My life-long field of interest has always been human development and relationships. But, as a parent of two donor-conceived young adults and Manager of the Donor Conception Network (DC Network), I also have more than a passing curiosity about the extent of the influence of genetic inheritance on an individual's way of being in the world. Having met adult half-siblings of one of the earliest sperm donors I have been shocked by the likeness of intelligence and speech patterns as well as facial features. Parents of donor-conceived children mostly do not spend a lot of time thinking about what their child might have inherited from their donor. Whilst not attempting to deny the role of genetics, DC Network members prefer to think about how much they can influence their child's life through the love and security they provide and the values that they will pass on. My own training and background convinces me that the provision of a loving and secure environment does have a profound effect, but what if the previously thought of ‘non-genetic' parent could have a genetic influence as well…an epigenetic one?
The term epigenetics first came to my attention about 18 months ago. Browsing a well known infertility web forum I came across a post which told of a branch of science that was proving that recipients of donated eggs could have an influence on how genes were ‘turned on' in the child they were carrying. It referred to an example from the equine world:
‘In horse breeding for example, it's not uncommon to implant a pony embryo into the womb of a horse. The foals that result are different from normal ponies. They're bigger. These animals' genotype – their genes – are the same as a pony's, but their phenotype – what their genes actually look like in the living animal – is different. The implication of epigenetics is that the child inherits characteristics from the woman who carries the child even if the original DNA comes from a donor egg. In other words the birth mother influences what the child is like at a genetic level - it IS her child.'
A flurry of postings followed which immediately latched on to the meaning that the posters desperately wanted it to have. This would not be a child that was not genetically connected to them at all… in fact, perhaps the donor could be air-brushed out of the picture because if genes were altered by the environment of the womb and the mothers were able to contribute to a baby's wellbeing through good diet etc, then maybe the donor didn't need to be acknowledged at all.
Whilst DC Network actively encourages would-be parents, those pregnant or already with donor-conceived children to own their status and authority as true parents, we are also clear that early honesty about beginnings is fundamental to healthy family relationships. Denial of the role of the donor is not helpful to child or parent, but, if epigenetics was able to show that a recipient of donated eggs exerts an influence on the way genes are expressed or silenced, what would this mean? At the very least it could be comforting information for women and their partners who discover that the only way they are likely to be able to have a child is with the help of an egg donor.
Sandy Starr of the Progress Educational Trust wrote to me when I first mentioned the way I had noticed emerging epigenetic information being used, saying that ‘the fallacy most commonly associated with classical genetics has been ‘genetic determinism', where more is ascribed to genes that they can truthfully account for. We may see a new fallacy of ‘epigenetic determinism', where epigenetics is used in the same way – for instance to overstate the influence of the recipient mother and impugn the contribution of the donor. Or conversely, we could see a fallacy of ‘epigenetic relativism' where the complexity of epigenetics is used as a pretext to dismiss all claims of genetic influence, which would allow people to dismiss the genetic contribution of the donor as effectively unknowable and therefore irrelevant'.
The challenge for Progress Educational Trust - and I am delighted that their autumn conference is focusing on this topic - is to come to a settled position about what the term ‘epigenetics' really means, and then to make sure that the implications for each area that this science applies to (cancer, mental health, reproductive medicine etc) are carefully unraveled and explained for non-scientists like me and disseminated in ways and in places that can genuinely inform and guide those for whom it may have great meaning.
If are interested in attending PET's annual conference Does Genetics Matter? Help, Hype and the New Horizon of Epigenetics, taking place in East London on Wednesday 18 November, contact Sandy Starr at sstarr@progress.org.uk or on +44 (0)20 7278 7870.
By Olivia Montuschi
Manager of the Donor Conception Network (DC Network)
No comments:
Post a Comment