New Zealand Listener - November 5, 2016

14 LISTENER NOVEMBER 5 2016

Dr Johnathan

Lancaster: “The

science is so far

ahead.”

I

magine you could test your baby

when it was born – or even before

• to find out what health conditions
  it was predisposed to, what drugs it
  should and shouldn’t take, whether
  it was likely to have an artistic or sci-
  entific bent, or whether it had the
  genes associated with aggression or
  risk taking. You could develop the ideal life-
  style plan to keep your child healthier and
  happier for longer.
  Well, the technology already exists,
  according to Dr Johnathan Lancaster, a
  world leader in molecular genetics. The
  complicated part, however, is how to apply
  it. “The science is so far ahead of where
  we’re at at a societal level,” he says.
  Lancaster was part of the team that
  discovered the BRCA1 and BRCA2 genes
  in the 1990s, since made famous by
  actress Angelina Jolie, who inher-
  ited mutations in those genes that
  vastly increased her risk of breast
  and ovarian cancer, subsequently
  undergoing a double mastec-
  tomy and then later having
  her ovaries and fallopian tubes
  removed. Lancaster is now the
  chief medical officer of Myriad

Genetics in the US, which offers a 28-gene

panel test to identify patients at hereditary

risk of some of the big killers, such as colon,

breast, ovarian, prostate, pancreatic and

melanoma cancers.

Recently in New Zealand to speak at

the Insight Forum at Middlemore Hospi-

tal’s Ko Awatea centre, Lancaster says far

more genes are linked to inherited can-

cers than we previously thought.

SNPs (single-nucleotide polymor-

phisms) are tiny but common

variants in the genome that are

responsible for the differences

between us. If you have enough

of a certain combination, they can

influence everything from hair and

eye colour to cancer risk and how

you metabolise drugs.

So in the future,

genetic testing has

the potential to

affect everything from the way medication

is prescribed – goodbye to the one-pill-fits-all

approach – to our public health-screening

programmes. But Lancaster warns there are

challenges ahead, particularly surrounding

ethics.

“If you take a blood sample from a pre-

viable baby and determine that it’s likely to

develop Huntington’s disease, what do you

do?” he asks. “You can’t have that conver-

sation without talking about termination,

which is massively emotive.”

Then there is the economic issue: who is

going to pay for all this testing? Lancaster

says in the US the average length of time

people stay with a health insurance provider

is 18 months. So purely from a business per-

spective, most companies are reluctant to

pay for tests that have no short-term benefit.

And who exactly should be tested?

“If you’ve got a group of people who are

overweight and diabetic and have a high

incidence of melanoma, is the No 1 requisite

for them gene panel testing?” says Lancaster.

“No, it’s not. It’s losing weight and stopping

going out in the sun without coverage.”

But if you’re an Ashkenazi Jew and your

community has a high incidence of BRCA

and BRCA2 mutations, then Lancaster

believes you should be tested as a matter

of course.

“And in 2016, in a nation as developed

as New Zealand, hereditary cancer risk

GENETIC REVOLUTION

JUST

GENES

Genetic testing now ofers personalised medicine, but

just who should be tested and why? by NICK Y PELLEGRINO

“I clearly remember

my boss saying, ‘You

can publish that if you

want to, but you could

end up with a bomb

under your car.’”