Re: Changes to NHS health checks must be evidence based and beneficial, say GPs
Proposals to include genetic testing in NHS health checks need to be meticulously thought through before we could reasonably consider implementing them. Genetic testing, although exciting and rapidly expanding, is still in its relatively early stages, and is something that we should be cautious about rolling out on a universal scale.
A huge number of questions still remain. Would we test only for specific alleles, or would the programme move towards genome sequencing, like many existing direct-to-consumer tests? In this case, what information would be made available to patients? We are able to identify risk alleles for a variety of conditions, such as apolipoprotein E genotype in Alzheimer’s disease, but in cases like this, it is still very difficult to modify the risk. We need to consider whether we have a duty to share all the information we can gather, when these results have the potential to be more psychologically damaging to a patient than they are beneficial.
We can think of predictive genetic testing as a screening programme, and it may be useful to look at it in terms of the Wilson-Jungner criteria for screening validity. For a programme to be valid, it must detect a condition at an early stage, at which treatment provides more benefit. In testing for genetic risk factors, we are identifying intrinsically unmodifiable risks. Although we can try to aggressively monitor for and treat coexisting risk factors, it is not clear to what extent this would actually influence outcomes. This is the most important factor if we are to consider introducing an enormous and costly programme to the NHS health checks. There are certainly cases where it can be beneficial, such as some hereditary cancer syndromes, but the impact is less clear when applied on a whole-population basis and to more minor risk factors. We do not have convincing evidence that genetic testing provides motivation for behavioural change; some studies have even shown that it decreases patients’ motivation.
Genetic testing has enormous potential both in targeted populations and for the future. One day, we may be more able to understand the nuanced picture it provides, and to personalise risk management and treatment plans to a patient’s DNA. However, it is hard to believe that we are at this stage now.
 Evans JP, Skrzynia C, Burke W. The complexities of predictive genetic testing. BMJ. 2001;322(7293): 1052-1056. Available from: doi:10.1136/bmj.322.7293.1052
 Wilson JMG, Jungner G. Principles and practice of screening for disease. Geneva: WHO; 1968. Available from: http://www.who.int/bulletin/volumes/86/4/07-050112BP.pdf
 Strafford JC. Genetic testing for Lynch syndrome, an inherited cancer of the bowel, endometrium, and ovary. Reviews in Obstetrics and Gynecology. 2012;5(1): 42-49. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3349923/
 Marteau TM, Lerman C. Genetic risk and behavioural change. BMJ. 2001;322(7293): 1056-1059. Available from: doi:10.1136/bmj.322.7293.1056
Competing interests: No competing interests