Doctor DNA

Using genetic information to prevent and treat illness is touted as medicine’s holy grail but NZ has largely been a bystander until now.

- RUTH BROWN

Greg Cubitt has not had an easy life. In his 61 years he's escaped death at least three times, suffering several workplace accidents and one assault, plus he has an ongoing battle to control his heart disease and type 2 diabetes. A massive heart attack in 2012 was not his first nor his last. Both his father and uncle died in their 50s after several heart attacks.

But in Cubitt's case, he's had an ally who has brought him close to winning his battle with diabetes. Since he was 18, he's been a patient of Dr William Ferguson, a GP in Kumeu, Auckland, who has been using genetic testing for clients whose health conditions defy standard treatment.

In 2016, Tokoroa-based Cubitt was doing his best to stick to a low-fat (for his heart), low-carb (diabetes) regime, but his blood glucose levels were out of control, and by then he'd already had five heart attacks. Ferguson told him to get up to Auckland and prepared to give him "the big talk" about taking his meds.

Then Ferguson got the results back from a genetic test he'd ordered on Cubitt. He called him in and said whatever carb intake you're on, halve it. Within a few weeks, Cubitt's diabetes was under control and he stopped the drugs for that condition.

Ferguson couldn't believe it. But the blood glucose results spoke for themselves - they were back within the normal range.

The genetic profiling also spelled good news for Cubitt's cardiovascular health.

Results showed he had a gene variant that impaired his ability to produce folate in its active form. Active folate has a protective role in the lining of blood vessels, so Ferguson put him on an active folate supplement.

Cubitt believes this intervention, on top of surgery, has lengthened the time between heart attacks, which used to happen every three years.

TAILORED DIETS

Using our genetic makeup to guide medical treatment is known as precision medicine.