Genetic code trial to aid treatment

00:50, Jul 23 2013

New Zealand doctors are a step closer to using patients' individual genetic records to make day-to-day decisions in the clinic and in GP surgeries.

A consortium including academics, clinicians and ethicists is about to roll out a national trial, in which around 50 patients will have their genetic code sequenced then used to aid their diagnosis and treatment.

Trials will mainly involve paediatric and cancer patients, but Tony Lough, CEO of New Zealand Genomics Ltd, said gene sequencing could one day be part of every GP's armoury, used for diagnosing disorders, predicting future health risks, and guiding choices of therapies.

"I'd roll into the GP, I'd have a National Health Index number, and they'd use that to pull out my genome, and then interpret it."

Lough said the trial is intended to demonstrate the extraordinary potential of "next-generation" sequencing machines, which have seen the price of sequencing an individual human genome fall from $3 billion in 2003 to around $7000 today.

In the decade since the Human Genome Project sequenced its first human genome, gene tests have had a huge impact on medical practice, but many believe there is more to come as the price keeps falling and our ability to analyse the data improves.


In May, Hollywood actor Angelina Jolie revealed she had undergone a pre-emptive double mastectomy, after a gene test showed that she had a variant of the BRCA1 gene which meant she had a high risk of developing breast cancer, sparking huge public interest in the potential to screen for genetic risk factors.

In 2009 Jay Flatley, chief executive of the US gene-sequencing company Illumina, told the UK Sunday Times that by 2019 it will be routine to map the entire genome of every newborn child, allowing their genetic profile to inform every medical decision taken throughout their life.

There's little evidence to suggest New Zealand is anywhere near meeting that kind of target. Here, genetic sequencing is used predominantly to diagnose rare childhood disease, and assist cancer doctors as they choose the best drugs for a patient.

But there are already numerous areas in which individuals' genomes could be used to supplement GP practice. Armed with a full genetic record, a doctor can predict if a patient is going to have a dangerous reaction to a common antibiotic, and how they are likely to respond to the blood-thinning medication warfarin.

Genetic records can also reveal some diseases before they have become symptomatic, such as the heart disease hypertrophic cardiomyopathy which afflicted broadcaster Paul Holmes.

Experts say that even if the results of genetic sequencing don't become part of our standard medical records, GPs are going to have to get to grips with understanding the data, as increasing numbers of people get their own DNA tested by companies offering limited tests for as little as $125.

Richard Wee, an Otago University researcher specialising in biomedical ethics, said GPs will increasingly face patients who turn up armed not just with a list of symptoms, but with their own genomic information, and what Google has told them it might mean.

Wee said GPs may have to take on the role of "genetic counsellor" for patients, explaining how their genomic data relates to their health.

Recruiting participants for the New Zealand trial will begin soon. One of the organisers, Otago University paediatric geneticist Dr Stephen Robertson, says the trial isn't strictly academic research.

Instead, the point "is to demonstrate loud and clear that this stuff has arrived, and we should be using it".

Sunday Star Times