Prof Hank Greely - Ethics and genetics

Professor Hank Greely from Stanford Law School explores some of the ethical issues around genetic testing for psychiatric diseases.
07 May 2014

Interview with 

Prof Hank Greely, Stanford Law School


Kat -  Now it's time to hear more from the Genetics Society Spring Meeting, focusing on genes and psychiatric illness. During the course of the meeting, scientists touched on a number of ethical implications and concerns about research and particularly testing for gene variations and faults linked to psychiatric conditions. So it was only fitting that at the end of the day, biological ethics specialist Professor Hank Greely, from Stanford law School, took to the podium to unpack some of these issues in greater depth. I started by asking him to explain some of his fears for this brave new genetic future.

Hank -   So, I worry that people will get tests of themselves, their children, their foetuses, their embryos and will be told, "Ooh!  There's a 10 times higher than average risk that this person/foetus/embryo will have Schizophrenia" and then will act on it.  In terms of the embryo, I'm not sure how great of harm that is.  In terms of the foetus - I'm pro-choice in American terms, I'm not opposed to abortions but I don't think aborting for a bad reason or for a scientifically incorrect reason is a good thing, going through that procedure for the woman involved.  I think about kids.  How would it affect a 12-year-old and his relationship to his parents in the world to be told he's at high risk for getting Schizophrenia?

Kat -   Because of course, carrying a gene variation or being told that you have this risk, it's not the same as having the disease.

Hank -   That's right.  There are times when it almost is.  So, if you have 72 CAG repeats on your huntingtin gene, that's the classic 100 per cent - everybody with the genotype gets the phenotype.  But the psychiatric diseases, even if you believe some of the studies and their huge replication problems with most of them, the highest risks were seen are about 30 per cent higher.  And so, if the background rate is 1 per cent risk for Schizophrenia, 30 per cent increase on 1 per cent is 1.3 per cent.  We also have to be careful.  People don't understand the difference between relative risk and absolute risk.  And so, 30 per cent sounds like a lot.

Kat -   That sounds like 30 in 100 people getting it.

Hank -   That's right.  It sounds like you're going from 1 per cent to 31 per cent, but you're going from 1 per cent to 1.3 per cent, and people aren't going to understand that.  So, I think we need to be very careful about how this information gets used with the public.  I'm strongly in favour of making sure they're learned professionals in between the genetic information and the individual patient or consumer who can sit down and explain it, and look at you face to face and see where you're confused or where you're troubled by something.  The direct-to-consumer movement here has almost religious advocates.  So based in the states, people who view, who say, "It's my genome, damn it, and the government isn't going to keep me from getting my hands on it."  I think that's crazy.

Kat -   The field that I know most about is cancer and cancer genetics.  Do you think that psychiatric genetics is kind of a special case and needs to be treated with maybe more care and delicacy than other diseases that affect other parts of the body?

Hank -   On balance, yes.  I'm a little reluctant to say that because I think we need to normalise psychiatric diseases.  They are diseases of the body.  They are diseases of the part of the body called the brain.  Just like all liver diseases are liver diseases, mental diseases and neurological diseases are all diseases of the brain.  And yet, I think in part because of the dualist notion that, no, these are diseases of the mind or diseases of...

Kat -   The soul...

Hank -   ...or of demonic possession or something else, they are more heavily stigmatised and we do need to be more careful about them.  It's also the case that they are harder in some ways to diagnose.  If you've got a malignant cancer, pathologists may have trouble figuring out exactly what the underlying initial cell was.  But they're not going to have any trouble figuring out you've got a malignant cancer.  A lot of the psychiatric disorders are very difficult to diagnose.  It's very difficult to define and I think we see that in part with the weakness of the genetic findings. 

We know from things like twin studies or sibling concordances that a lot of these diseases have to have powerful genetic components.  There's just no other explanation for why 1 per cent of the general population would get, but if you were an identical twin and your twin has it, you have a 70 per cent risk or you have a 10 per cent risk.  So, it's got to be genes at work. It's just getting there, particularly when it works through what I think is the most complicated known object in the universe -  the human brain, there'll be a lot of complexity: hundreds of genes involved, lots and lots of life experiences, probably lots of unknown and perhaps unknowable times when chance plays a role. 

So, I do think we need to be particularly careful about it, mainly because of the potential for stigma, as well as the fact that these are going to be about the most complex things.  Any kind of behavioural traits whether it's a mental illness or something like math ability or personality, it's going to be incredibly complex.

Kat -   As far as you're concerned, maybe looking into the immediate future, what one thing are you most excited about the potential of genetics for understanding psychiatric disease and what one thing are you most afraid of or concerned about?

Hank -   I'm most concerned about, it's possibility for misuse - that people will start using it too early and make decisions about themselves for their family members that will be bad decisions.  I'm worried about that because the incentives are all for hype and for exaggerating the power of this. The social incentives for scientists, the incentives for journalists, the incentives for companies all push in one direction and that can lead to bad things.  The hope is that this will tell us something about what causes some of these diseases or maybe in some cases, how many different diseases we're dealing with. 

I'm not convinced Schizophrenia is one thing.  It's like we use to think hepatitis was one thing, inflammation of the liver.  We now know there are a lot of different causes of hepatitis and knowing that there are different hepatitis has helped us understand how to treat them and how to cure many of them.  So, it's an exciting time of learning more about what's causing these diseases and genetics can give us some clues and maybe even some real answers there.  The amount of human suffering that could be avoided with some good treatments or preventions from mental illnesses is truly staggering. 

If I had the power to cure or prevent just one disease, I think I'd pick Schizophrenia.  1 per cent of the population has it.  It's incredibly disabling and it's incredibly cruel because it usually strikes people.  So, just coming in to their own in their late teen years or in their early 20s, normal, happy children become severely, severely disabled by this terrible mental illness.  Anything that can help us cure that or even treated better would be a good thing.  I think genetics provides some hope, but we're not going to do it tomorrow.  It'll be a journey with lots and lots of steps and we have to avoid overhyping any one of the many steps on the path to what could be one of the greatest benefits conferred upon mankind.

Kat -   That was Hank Greely from Stanford Law School in California.


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