In 2022 scientists in the USA were jubilant to have completed a human genome mapping process, which was decades in the making as previous technology did not allow for a small but significant percentage of human genetics to be mapped. Jonas Korlach, the chief scientific officer of Pacific Biosciences, the company that provided the technology in this endeavour explained that if genetics were a detective story, “precisely the pages where you would find out who the murderer is were missing.” While this completed mapping process is truly a breakthrough in genome sciences, it will still be years before the results of this victory can be properly adopted in medicine and healthcare.
Genomic technologies are expected to set the tone for medicine and medical research all over the world. With the great strides that genome testing is making it is becoming possible to predict future diagnoses in a human being and as a result, it is impacting decisions regarding patients and their wellbeing in a significant way. On the downside, while genome testing allows for predictions to be made about a person’s health, with treatments not yet discovered for certain diseases, it places both the family of the patient and the patient in a precarious situation.
What are genomic technologies exactly?
In simple terms, genomics involves studying human genes and chromosomes which make individuals unique in their own way. Usually, the human genome contains 23 pairs of chromosomes and 24,000 genes. What genomic studies do is to discover a human being’s genetic composition along with how they differ from person to person and how these genes mutate over time. Thus, this will allow for a never-before-reached specificity in treating a patient based on their exact genetic construction and behaviour.
DNA and genome sequencing shows how a person’s DNA is made up. While it consists of four bases known as A, C, T and G, every individual’s genome is made of a certain pattern of these four. Gene editing studies first began in 2012 when a study showed that the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), combined with an enzyme called Cas9, could be used as a genome‐editing tool in human cell culture.
The mapping of genomes has opened up a well of information that was earlier inaccessible to us, such as how humans survived illnesses such as plagues, infections and various diseases in history, and how each person can respond to different types of medicines.
In humans, genomic editing can be conducted in different ways. One in which only the human embryos or germline cells are edited and the changes that happen can be passed on through the generations of that person. The other is the editing of somatic cells which does not affect the person’s bloodline. These two variations have been called Germline Genome Editing (GGE) and Heritable Genome Editing (HGE), respectively.
The prognosis
Genomic technology, on the surface, seems to be a blessing. After all, it can spare many people countless months of suffering if they can identify the risk of getting certain diseases and illnesses and start preventative healthcare, if possible. I remember watching a TV series recently where a young lady in her 20s whose mother died of breast cancer submitted herself to testing where she found out that she was carrying the same gene mutation – the BRCA (Breast Cancer) gene mutation – that made her susceptible to breast cancer as well. This led to her evaluating her options and finally opting to have a mastectomy and then reconstructive surgery. Her story had a happy ending.
But this is not always possible. Certain diseases and illnesses that are identified through genomic testing may not have treatments prepared and ready. This means that the person who finds out that they have a propensity for the illness will have to live through countless months, if not years, of worry. It somehow seems to be an unfair tradeoff in order to live a longer, more productive life. Certainly, we all live with some type of risk every day. Yet, this does not mean that we fear for our lives in a tangible manner. With genomic testing, the risk becomes very real. It is given a name and a percentage of influence in your life, which then dominates your daily living.
When healthy individuals are screened for diseases using genomic technology many gene defects could crop up, which poses a problem in treating such patients. It is only when there is a single gene defect that is behind the probability of a disease that treatment is possible. Studies show that many of the more common diseases are caused by a flaw in two or more genes and other external factors such as the food you consume and the lifestyle you lead. Thus, it then becomes complicated as to how someone can deal with diseases that cannot be treated at this point.
The ethical debate
As with everything, it is possible that the underprivileged will be left behind in these scientific breakthroughs because they will not have the money or the resources to ensure that their children are cured of genetic diseases or that their future generations are made free of them. However, the newer CRISPR/Cas9 genome editing technology is considered to be more efficient and cost-effective than other such genomic technologies. Yet, this also poses questions about ethics, as to how right it is to do genetic editing to such an extent that a certain gene is completely removed from the bloodline as then, even the potential impairments that result can be passed on through the generations. The National Human Genome Research Institute says that “Due to the possibility of off-target effects (edits in the wrong place) and mosaicism (when some cells carry the edit but others do not), safety is of primary concern.” Further concerns include those “about diminishing the dignity of humans and respect for their variety, failing to appreciate the importance of the natural world, and a lack of humility about our wisdom and powers of control when altering that world or the people within it”.
In their article ‘Beyond safety: mapping the ethical debate on heritable genome editing interventions,’ which discusses the ethics of heritable genome editing interventions, Mara Almeida and Robert Ranisch also show that, “Heritable human germline modifications are currently prohibited under various legislations and surveys show public concerns about such applications, especially without clear medical justification. Furthermore, religious concerns have also been added to the ethics debate regarding genomic technologies as they involve the creation and destruction of embryos, which is akin to playing God.
The future of genomic testing
According to David Ledbetter, a former professor at the University of Florida College of Medicine-Jacksonville, “Genome sequencing will become the universal genetic test.” He predicts that in future, a human being’s genome will be sequenced once and the analyses repeated as necessary. He also says that the processing time will be 24 – 72 hours, which is quite rapid. Ledbetter adds that genome sequencing will be done at different times in a person’s life as people enter the various stages of their life. He also expects the process to be more affordable with the predicted cost being around $500.
Overall, it sounds exciting and terrifying all at once. If given the opportunity to eradicate a genetic disease from one’s self or one’s family line, would we take it? It is a tempting offer, but one that we still don’t know enough about. And even years down the line, if this becomes the status quo just like vaccines did, there is no doubt that the majority will jump on the bandwagon. The question remains, however, can we truly understand what we are getting into? While I am no scientist, in my mind there is always that inkling of fear about any type of Frankensteinesque technology and what repercussions they may bring in the future.
(Anouk De Silva)