Dr Arya Anthony Kamyab
Imagine being able to screen an embryo’s DNA and predict the likelihood of developing diseases such as diabetes or schizophrenia. DNA technology has been knocking on the door of health innovation for some time, and it looks as though it has finally arrived in the NHS.
The government’s 10 Year Health Plan for England aims to “provide a genomic test for every newborn baby by 2035,” Health and Social Care Secretary Wes Streeting confirmed to the House of Commons this month.
This would require redesigning our current practice. At present, when babies are born, the heel-prick test screens for nine rare conditions using biochemical markers. The plan to introduce genetic testing will entail all newborns in England having DNA screening which, rather than looking for chemical markers, uses whole genome sequencing to look for changes in genes associated with more than 200 conditions that can be improved if identified early.
Genetic screening is not intended to replace the heel-prick test, which will continue to be carried out regardless of whether parents decide to opt out of genomic screening.
Genomics England is helping lead research. It’s 100,000 Genomes Project has sequenced more than 85,000 participants’ genomes, with 18.5% of data so far turned into actionable findings. The Generation Study from Genomics England plans to build on these foundations to sequence the genomes of a similar number of newborn babies. This genomics information will be interpreted through AI to help predict and avert genetic illness before the onset of symptoms.
Predictive Power
DNA is not a deterministic code with a unique ability to predict the future. Modern science has linked certain genetic variants to specific diseases. However, countless others — known as variants of uncertain significance — remain unclassified, their potential harmful, neutral, or beneficial. Some of these variants, which currently evade our 21st century understanding of genetics, will inevitably be associated with diseases. This project could undoubtably illuminate many of those missing gaps and transform our knowledge of inherited risk.
So, what undermines DNA’s predictive value in determining who we grow up to be? We can break the answer down into three reasons: incomplete penetrance, variable expressivity, and being heavily shaped by environment.
Incomplete penetrance is a fancy term used by geneticists. It refers to a scenario in which individuals carry a specific genetic mutation but do not always express the associated disease or trait. We see this with the BRCA1 gene, which increases the risk for breast and ovarian cancer, but not all carriers develop these diseases. Then we have variable expressivity, which often gets confused for penetrance but is a distinct concept. Where penetrance concerns itself with whether the trait (or condition) will appear, expressivity describes its severity or types of symptoms once present.
Finally, the interplay between genes and environment is vital for the presence of disease. But have you ever considered how the knowledge of genetic susceptibility may affect one’s behaviour? If you were to know that your genes confer a greater risk for, say, diabetes, could that lead to behaviour modification? Fewer takeaways and more exercise?
The Ethical Minefield
Make no mistake, having access to genetic information will save lives and reduce suffering. It will further our understanding of genetics, a foundational pillar of medical science. This doesn’t make the debate a foregone conclusion, however, as the ethical terrain is incredibly complex.
The Generation Study is not sequencing parents’ genes. However, it would mean universal screening of babies’ genomes before they can consent.
Few could argue that telling parents that their child has a noncurable condition will unleash significant anxiety and stress. Some may argue it is not worth the potential benefits, while others may prioritise the long-term gains in scientific advancement.
Research published in the Nature journal European Journal of Human Genetics suggests that most parents would plan to tell their children their screening results in childhood, whilst some would postpone this news due to the potential negative impacts it may have on their self-esteem.
Perhaps, then, this scheme should report only on a predefined panel of conditions where early treatment makes a significant impact on outcomes. What makes a disease “treatable” or not is also not black and white and will raise further difficult questions. But this is where we have to be careful. The argument against screening for diseases that are not treatable in 2025 overlooks the fact that such programmes generate valuable data, which can play a role in the development of future breakthroughs and therapies.
Consider knowledge as a burden for a moment. We know of genetic variants that are associated with Alzheimer’s disease. How are parents supposed to raise a child that they know has a genetically increased risk of developing Alzheimer’s? For some, the answer is simple: Do nothing. The exact cause of Alzheimer’s is not understood, which means there is no certain way to prevent it. But this reductionist approach of simply deciding to do nothing is much easier said than done.
Regardless of whether you choose to report on only a predefined panel of conditions, patients will know that the data exist. Once the genome is sequenced, it cannot be unsequenced. Doctors, geneticists, and academics will have to carry the moral burden of knowing more than they can responsibly act on. And what about patients? If they know that the data exist but are withheld because conditions are deemed nonactionable, what will stop them demanding the information and paying a third party to interpret the results? If so, we risk creating a two-tier system where genomic knowledge is in the hands of the most affluent.
The Slippery Slope to Discrimination
The most common fear that populates headlines is the misuse of genetic data. A reference to George Orwell’s 1984 is never too far when data acquisition for “the greater good” is mentioned. Maybe we can begin a new movement, calling this Orwell’s Law? But this concern deserves to be taken seriously. In philosophy, a slippery-slope argument is when a decision is rejected because the arguer believes it will lead to a chain reaction that results in an undesirable end. The issue with slippery-slope fallacies is that they are incredibly easy to make and the proponents often fail to do the hard work of logically connecting each step to show why one outcome would lead to the next. So, are the concerns legitimate?
Genetic test results can affect insurance policies. In the UK, insurers cannot ask you to take a genetic test, but they can ask for results of a test if you have already taken one. If genetic testing becomes widespread, it may prove difficult to keep this information from insurers. Others may also want access. Genomic data are akin to your identity. The acquisition of this information creates a layer of vulnerability that understandably makes many nervous. Could employers make decisions on whether to hire someone with a predisposition to a mental illness, for instance?
And yet despite all this, it would be terse to flat-out ignore what this technology may be able to bring. Identification of, say, spinal muscle atrophy at a presymptomatic stage can significantly improve outcomes and slow the progression of disease.
This debate is complex but at the same time fascinating. We are remoulding healthcare and shifting the timescale for where medicine begins. But this comes with risk and ethical questions.
Arya Anthony Kamyab is a foundation year 1 doctor working in the Northeast of England. You can follow him on Instagram @aryak.writes.