Back in February of 2019, Matt Hancock, health secretary, strongly advocated for the idea of the NHS providing predictive genetic tests for common cancers and heart disease. A sense of threat, however, ensued after his comments and, since then, there has been no mention of such an undertaking by the NHS. Genotyping, for instance, is mentioned in neither the Conservative nor the Labour manifestos. This is a mistake.
The original plan was for the NHS to partner with Genomics England, a company owned by the Department of Health to offer subsidised DNA sequencing to volunteer participants. The service would probably be offered for around 500 pounds – depending on the level of subsidisation. Each volunteer would’ve received a personalised genetic screening and agreed to contribute their data to research, with the aim of improving the genetic prediction power of diseases.
The story, at the time, was quite famous and caused people to ponder questions like: what if Genomics England (the company that would’ve worked in tandem with the NHS) gives people inaccurate information? Would they sell our data? If people had to pay for such a service, wouldn’t this create a stratified health system (i.e. enhancement for the rich and bog-standard for the poor)? All appropriate questions; but commentators should remember that genotyping and collection is already on the march forward. Direct-to-consumer (DTM) Companies, such as 23andMe, already provide a commercial service that tells those who are willing to pay about their ancestry as well as medical risk. So, in a way, genetic risk prediction already exists and is a currently only available as a private pay for play service.
DTM companies are still relatively primitive in what they offer – mainly focusing on identifying single genes, like APOE (apolipo-protein E) or the TTR gene (transthyretin). One variant of the APOE gene, if it that turns up on both chromosomes (one from your mother and one from your father), yields a 40 per cent Alzheimer’s disease risk increase. These single gene effects are, however, extraordinarily rare. Most diseases, for instance, are influenced by many genes of small effect sizes (usually only increasing risk by as much as 0.1 per cent). Relatively speaking, then, the APOE Alzheimer’s variant is an unusually big fish in a pond of the abnormally small. Many people choose not to have their APOE variants revealed to them, citing their belief that the risk information would not be of much help to – as there’s no silver-bullet prevention nor a cure. A glass half full perspective, though, might see this information as a chance to arrange life insurance (insurers are not allowed to use genetic information), plan for later social-life and enjoy the present moment more. To delay onset, a person may also want to adapt their lifestyle or career choices; for instance, a career in boxing or the NFL are probably not the best options for those with a 40 per cent increase of developing Alzheimer’s. Thus, given these considerations, it could even be argued to be unethical for a universal healthcare system (like the NHS) not to provide this genotyping technology affordably to the millions.
The DNA explosion has recently combusted another important advance: that of polygenic scores. The majority of diseases, and traits in general, are influenced by thousands-upon-thousands of genes that individually contribute miniscule effects. These known genetic effects concerning a disease can now be summed in a composite score, known as a polygenic score. These scores aren’t just comprised of just a few genes that contribute big effects, they’re made up from all genes that are known to contribute an effect – big and small. Polygenic scores have become competent at predicting common disorders, as well as things such as educational attainment, from knowing nothing more about a person other than their genetic sequence.
The current polygenic score for coronary artery disease has recently shown its predictive muscle. This score can identify 8 per cent of the UK population who are three times more susceptible of suffering from a heart attack. For comparison, a high coronary polygenic risk score is ten times more predictive than the measures of a person’s cholesterol. Although the majority of polygenic scores only currently explain around 3 to 5 per cent of the risk of common disorders, they are some of the best medical predictors we have – and they will only get better, but only if researchers ascertain more genetic data. If, then, the NHS could provide a heavily subsidised genotyping service, it would be able to give patients risk scores in tandem with preventative advice and would, at the same time, gain the all-important genetic data that is vital to make these polygenic scores more comprehensive. It’s a two birds with one stone situation.
Polygenic scores have the ability to help sustain the NHS financially through bettering its ability to predict patient disease before its manifested, meaning it can prevent problems before the show of malignant symptoms. The NHS could offer polygenically based preventative plans and would know what markers to look for before a disease presents. We should jump at the chance to promote self-knowledge, health and illness prevention. And these benefits should not only be for the wealthier strides of society, but for all – with genetic risk and cost spread progressively among the tax paying British population.