Should all newborns be offered DNA sequencing?
The human genome project cost $2.7 billion and took 13 years to read all 3 billion genetic letters in the human DNA code. But since then, the molecular biological revolution that has swept the globe means that this feat can now be achieved for less than a 3 figure sum and in hours not years. The result is that proposals are now springing up to unleash this technology as a screening tool for newborns. It sounds like a good idea: let’s bank everyone’s DNA code at birth. But, speaking with Chris Smith, what does Anneke Lucassen, director of the Centre for Personalised Medicine at the University of Oxford, make of this?
Anneke - Last two decades there's been absolutely amazing strides in technology. We can look at a person's entire genetic code quickly and cheaply. But we wanted in this paper to look at some of the ethical issues that that raises dealing with genetic information. In particular, we're focusing on plans to look at this technology as part of newborn screening. Currently in the UK and many other countries, what's offered is a screening test when babies are usually sort of newborn, five days old, they get what's known as a heel prick test and that looks for some very rare genetic conditions. And the proposals are to massively expand this heel prick test to look at the entire genetic sequence. We wanted to look at some of the issues that that raises.
Chris - As one person put it to me, once with genetics, you get the answer to the question you ask. So if we just screen the genomes of hundreds of thousands of newborns, all we'll know is their genetic code. We won't know anything about outcomes yet, will we?
Anneke - Yeah, I like that quote. You get the answer to the question you ask and I think that's really interesting because of course when you read about genetics in the media, newspapers or, or even sort of just listening to people's understanding of genetics, we hear a lot about people saying, well, it's in my DNA. People tend to think that genetics is really clear cut. You'll be able to look at your genetic code and make clear predictions from it. But you are absolutely right. All we can really do is look at the sequence and interpreting what that means for good or ill health is a a much more complicated nuance step.
Chris - One of the criteria for doing screening for anything is that we only screen for things that we think we can do something about. But I suppose inevitably when one reads the genetic code, you're suddenly armed with all the knowledge and you don't know what you do know and what you don't know at this stage. So are we screening for things we can't do anything about therefore?
Anneke - Yeah, that's another really interesting question. I mean, some people would say that making reproductive choices or deciding whether or not to have children or testing in early pregnancy might be something that could be done about it. That means that a diagnosis is helpful even if that diagnosis itself isn't treatable by a medication for example. So that question that you say rightly raise of, is there an intervention we can offer is again more complicated than we first thought? It's not just about is there a tablet I can take if I diagnose this? Do people want to know this to make future decisions? And that of course varies from person to person. So I think it's much harder than people thought to say, is it worth screening for this particular condition or not? We can make generalizations. So we might say actually screening babies for adult onset conditions is probably not a good idea. Because there's nothing that you're gonna be able to do in the next 20, 30 years. But even then some parents will say, well that will be useful for me to know so I can guide how I bring my children up.
Chris - What do you think the really big problems that we're gonna have to confront around this are then?
Anneke - There's loads of big problems, but let's focus just on the newborn screening. The biggest problem is that it's been proposed to end diagnostic odyssey. So a diagnostic odyssey is a something that could be ended by sequencing our entire genetic code or genome because many of the people diagnosed by whole genome sequencing had had many, many investigations before then. And this cut short those investigations. The problem in newborn screening is that you might be starting people on diagnostic odysseys rather than ending them. 'cause You're starting with a healthy baby and your ability to predict what the genetic code means in them is much, much poorer than starting with someone with particular signs and symptoms where you are using the genetic code to make that diagnosis. So I think the starting of a diagnostic odyssey and the consequences that has for the NHS of needing to follow up lots of children or otherwise healthy babies for a long time, to see whether a variant really means what we think it does, they haven't really been factored into the equation at all yet.
Chris - Do you have any kind of solutions to this or to your mind? How should we go forward? It's a good idea to learn about the genome. It's a good idea to be able to marry up what's in our genomes with what our eventual disease outcomes are because we can then begin to unite cause and effect. But how should we be going forward on this?
Anneke - Well, I'd say cautiously. So I think, is it a good idea asking that question? Is it a good idea and in what circumstances is it a good idea? I'm not at all convinced it is a good idea to offer this to healthy newborns. I think it would be much more effective, particularly at the time that the NHS is is in crisis already be much more effective to offer whole genome sequencing to ill newborns. It's very effective there. But I think to jump from saying we can do it technically to, we must do it is a jump too far for me.