Genome sequencing is "revolutionising" medicine, but it could also have a huge impact on how society deals with criminals found to have a genetic predisposition towards violence.

Developments in the past decade have led to the cost of mapping the human genome plummeting in recent years. A person can now have their entire genome sequenced for about $10,000.

Dr Tony Lough, chief executive of New Zealand Genomics Limited, said the reduction of the cost has expanded the opportunities for use of genome sequencing. More people are now seeking to get their genomes mapped for the potential medical benefits, however there are issues around how that information is interpreted.

Medical scientist associate Professor Cris Print, from the University of Auckland, said genomics is beginning to "revolutionise" medicine, helping experts make diagnosis and prognosis, by enabling treatments to be better personalised, through testing of genes before birth (either pre-natal, pre-implantation or in vitro fertilisation, or pre-conception), and genomic-enabled screening programmes.


However Dr Print said genomes are difficult to interpret.

"Having a particular mutation doesn't necessarily mean you are going to get the disease. For many mutations or variants in your genome, you may or you may not get a disease, and whether you do or not depends on luck, environment, your diet, what infections you had as a child, what exercise you do and so on."

Dr Print said it is important to recognise that while a certain gene may indicate a patient is susceptible to suffering from a particular disease - it does not mean they will get it.

"Usually genomic analyse gives you a very weak probability, you don't know [whether you will actually get a particular condition]."

While the science has multiple applications in the areas of medicine, agriculture, horticulture and the environment, there are potential negative impacts.

For example, genomics could have a major effect on court decisions in the future, Dean and professor of law at the University of Otago, Professor Mark Henaghan said.

"A couple of very large studies are shown a particular gene, the MAO-A gene, combined with an environment where the person is treated very badly, is abused when they are very young ... the absence of that particular gene and negative environment means that people are more likely to act out in a violent manner," he said.

"So it comes down to the whole issue of responsibility. Should we hold such people equally responsible when they have this physical genetic factor which is going to drive them more closely to behave in certain ways than perhaps others who don't have it?


"Should we apply the same laws to them, or should we give them some recompense? Or the other way to look at it - and some people would look at it this way - is to say 'if they are like this then they are highly dangerous and we should lock them up for long periods of time.

"This information can be used in a way that is quite draconian."

Dr Henaghan said there are also issues around employers or insurance companies getting the information and using it against individuals.

"The more information that is out there about a particular person, the more risk that certain people could be discriminated against, maybe limitations are put upon them ... especially if that information is misinterpreted."

Dr Henaghan said there is no legal requirement to tell family members of people who have their genome sequenced that they may also have a predisposition for certain conditions.

"The general feeling is if it is a predisposition that you can do something about, through an adjustment in lifestyle or certain treatment ... most people would agree it is a good thing to tell other people. There is a right not to know, and some people may not want to know if they have a preposition or are susceptible to diseases which don't have any cure."


Dr Henaghan recommended people who get the genome sequence done should speak to a "genetic counsellor", rather than seeking to interpret the information online themselves.

"We've got to educate people about how to interpret this information," he said. "The more we open the debate, the better it is for people to understand what it all means."

Meanwhile Dr Print said New Zealand can play a big role in genomics.

"We've got a very diverse population, we have all sorts of different ethnicities in our population, we've got genomic scientists in New Zealand that are quite well connected internationally ... we've got this number eight fencing wire mentality where we make things work.

"Right now most clinical genomics with patients is done as part of research projects. We're not quite yet moved into routine use of clinical genomics outside of research projects - but it is coming very quickly.

"I think one thing is very clear that the public are not informed, we need a lot of public debate and discussion. For example seeking informed consent from a patient is very difficult at present when you are describing complex genomic disorders."


"The technology is racing along so quickly and there are huge benefits to be had but I think where patients are concerned we need to be cautious and get it right."