The best of men cannot suspend their fate: The good die early, and the bad die late.
— Daniel Defoe. Character of the Late Dr S. Annesley (1697).
It is human nature to want to know why things are the way they are now and what will they be like in the future. In our lifetime, advances in the science of genetics have helped to provide the explanation for what we see in ourselves and a crystal ball into our biological future. As we all know – from the first time we heard the phrase ‘nature versus nurture’ – genetics doesn’t provide the whole answer to the puzzle, but increasingly it is being used to assist our patients. As an obstetrician and gynaecologist, genetics has become an everyday part of my practice. In the past few weeks I have counselled a couple on prenatal testing for aneuploidies, then on interpretation of an inconclusive result and explained the limitations of determining the risk of autism in their fetus. For a patient planning hysterectomy, a discussion of family history and risk of genetic cancer syndromes was a part of taking her medical history and informed her decision to opt for ovarian preservation.
While it may seem that the furthering of our knowledge of the inheritance of disease can only be positive, one does not have to search for long before reaching a dilemma. Perhaps one of the starkest examples of the benefits and problems of genetic advances in medicine is that of Huntington’s disease. In the case of this condition, genetic testing can inform an asymptomatic patient that they are definitely going to develop an incurable disease or, alternatively, that they will never develop the disease. Such life-altering information has the potential to have a profound effect on relationships, careers and health insurance. If it was you, would you want to know?
In obstetrics, we have recently seen the emergence of non-invasive prenatal testing (NIPT). On the positive side, NIPT has allowed the earlier detection of fetal aneuploidies, with a reduced need for invasive testing and the possibility of earlier termination of the pregnancy, if that is chosen. Currently, NIPT is performed at ten weeks gestation, but it is conceivable that it will be possible to perform the test at an earlier gestation in the future. For aneuploidies this may well be advantageous, but NIPT can also reveal the sex of the fetus. Until very recently, the majority of pregnant women could not find out the sex of their baby until ultrasound at about eighteen weeks gestation, a time after which termination for maternal choice is unavailable. As NIPT and similar technologies become more easily available, and one can only imagine it becoming cheaper and less well-regulated on a worldwide basis, it is perhaps inevitable that they will be used for sex selection in the first trimester. One could suggest not reporting sex chromosomes on NIPT unless there was an abnormality, but it could be argued that this restricts a woman’s choice to know all the available information about her pregnancy.
This issue of O&G Magazine explores the theme of genetics with a range of articles on topics from the state of the art in the genetics of gynaecological cancer and prenatal screening through to that of sex selection, while an article on genetic counselling outlines the support our colleagues can provide in this important area.