For most of human history, the cause of infant mortality was a mystery. Modern medicine has solved large parts of that riddle for us, thanks in no small part to technologies like genetic screening and ambitious research like the Human Genome Project. Today, sick babies are routinely screened for a bevy of congenital conditions using whole genome sequencing — and soon, their healthy counterparts might be as well.
In September 2021, Genomics England, the U.K.'s premier genomics research organization, announced its intention to move forward with a pilot program that would use whole genome sequencing to screen for hundreds of genetic diseases in 200,000 otherwise healthy-seeming newborns. The initiative (called the Newborn Genomics Progamme) was received favorably by the U.K. public following an open dialogue sponsored U.K. Research and Innovation's Sciencewise program. However, the announcement sparked controversy in the scientific community.
The debate boils down to this: How helpful is genome sequencing for babies? And, on a more existential note, if everyone knows their full genetic history, how do we prevent society from going full Gattaca?
What Is Genome Sequencing?
A genome is a map of an organism's entire genetic code, one that includes every gene, active or not. While the human genome gets a lot of attention, it's not the only genome that scientists have sequenced. To date, we have full genomic data for more than 350 species of plants, more than 250 animals, and a whole bunch of microorganisms, including the SARS-CoV-2 virus.
Both our understanding of genomics and genomic sequencing technology have come a long way since the 1990s. Though it took 13 (ahem, 31) years to sequence the first human genome, today scientists can reliably sequence one person's genome in around 24 hours, and for substantially less money. "Since the end of the Human Genome Project, the cost of sequencing DNA has gone down a million-fold," says Dr. Eric Green, director of the National Human Genome Research Institute in the U.S.
Genomes — including our human ones — are incredibly valuable scientific tools, because they allow researchers to study how different genes interact, and they provide a baseline against which to compare bits of an individual's DNA, or even their entire personal genome.
So with that in mind, what are the potential benefits to infant genome sequencing?
Having a newborn's complete genomic information can enable doctors to catch and treat certain genetic conditions right away — for example, children born with severe combined immunodeficiency (SCID). The disease, which suppresses immune function by way of multiple white blood cell mutations, was once considered a death sentence. But infant genetic testing has rendered SCID, while still serious, treatable.
In fact, infants in the U.S. and the U.K. are already routinely screened for a number of genetic conditions using a small blood sample and some basic DNA amplification. Babies who develop complications after a couple of weeks receive a more thorough battery of genetic tests, including whole genome sequencing. Which leads proponents of infant genome sequencing to wonder: Why shouldn't doctors just go ahead and do a comprehensive check from the start?
"It's really odd that we still do this for just three or four dozen diseases," says Green, "when we could detect literally thousands of diseases if we did it at birth."
In addition, he points out, having a full genome scan on hand could prove useful to people later in life; he envisions a world in which primary care physicians can tailor each patient's health care regimen to suit their genomic needs. And while there are still a lot of unknowns when it comes to making gene-based diagnoses, having more data will ultimately help fill in the gaps. "We need to give those physicians the tools," Green says.
Not everyone is sold on across-the-board infant genome sequencing, however. "I'm not a fan," says Dr. David Curtis, a geneticist specializing in psychiatric conditions at University College London.
Imagine knowing from the moment you were born how you were most likely going to die. One of the potential issues with genomic screening, Curtis says, is exactly that: A patient might uncover an incurable condition that won't affect them until later in life.
Take Huntington's disease, for example. This rare neurodegenerative condition, which causes tremors, cognitive difficulties and seizures, doesn't typically rear its head until a person is in their 40s. However, it is easily detectable by genomic screening from birth. To date, there is no effective treatment or cure for Huntington's.
Some folks might prefer to know what's in the cards for them upfront; but for others, such knowledge constitute a living nightmare. Not to mention the issue of privacy — all of that data has to be secured in a large national database, and as recent ransomware events have shown, no database is completely hack-proof. In Curtis's view, the sticking point is consent. "A lot of it is actually applicable, you know, to 18-year-olds," he says, "Not to newborns."
Another consent issue is linked to the nature of DNA itself. Since our DNA is inherited from our parents, all humans essentially carry two genomes with them: one from their mother, and one from their father. In turn, each parent shares a genome with their parents, and so on. Factor in other relatives, like brother, sisters, uncles, cousins, etc. and things quickly get messy. After all, even if the baby in question is fine putting their genetic data into a national database, their grandparents might not be so keen on it.
"So," says Curtis, "it is a bit of a big deal."
Ultimately, though, universal genome testing might be less a question of if, and more a question of when. With Genomics England's Newborn Genomics Programme (and others like it) receiving an increasing amount of public and governmental support, it seems likely that whole genome sequencing will become standard practice at some point in the not-too-distant future.
"It'll be a grand experiment," Green says.