16 LISTENER NOVEMBER 5 2016
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GENETIC REVOLUTION
Angelina Jolie inherited genetic mutations that
convinced her to have a double mastectomy and
get her ovaries and fallopian tubes removed.assessment should be part of every medical
encounter,” he says.
That can be as simple as a GP asking ques-
tions about family history of the disease. If
you have two or more close family members
with certain types of cancer, clusters of a rare
cancer among your relatives, or incidences
of very early diagnosis or multiple primary
cancers in the same patient, it should trigger
a doctor to explore further.
For those who get preventive testing and
discover they are at high risk, there are clear
guidelines on how to progress. “So if you
inherit Lynch Syndrome, which increases
the risk of colon, endometrial and ovar-
ian cancer as well as some genito-urinary
and skin cancers, you’ll undergo regular
colonoscopies, pelvic ultrasounds and skin
screenings,” says Lancaster. “You might have
a hysterectomy and removal of the fallopian
tubes and ovaries.”SAVING LOTS OF LIVES
As we learn more, gene panel testing will
cast a wider net. But as Lancaster points
out, it already has the potential to save large
numbers of lives.
“Someone with BRCA1 and BRCA2 who
has a mastectomy has a 90% risk reduction
for breast cancer, so it’s massive,” he says.
“We see mutations in 23% of patients with
ovarian cancer when we use panel testing,
in over 20% of breast cancer patients and
around 11% of colon. So these are not small
numbers.”
This sort of precision medicine could
eventually take over from the current blan-
ket approach to public health screening- where we’re advised to get a mammo-
gram, pap smear or PSA test just in case,
no matter what our personal risk. Lancaster
talks about a future where couples will have
the option of pre-nuptial compatibility test-
ing before they decide to get together and
start a family. And in-utero testing before
a fetus is even viable will make possible
predictions about life expectancy and the
diseases that individuals are likely to develop
in their seventies or eighties, as well as how
best to treat them.
In a society that’s wary of eugenics and
conflicted about abortion, this makes for a
lot to get our heads around.
Lancaster tells a story about sitting down
with his mentor shortly after the BRCA1 and
BRCA2 mutations had been identified and
discussing how medics now had the ability
to test an early embryo for the genes, just
as we do for Down syndrome.
“We’d written a position paper that said
the technology exists; therefore, someone
is going to ask for it. So let’s have a discus-
sion about where we’re at, let’s initiate the
dialogue so that at a societal level we cancome up with a position,” he says. “And 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.’”
Even if we do wait to test until after a
baby is born, there are still ethical consid-
erations, he points out. You might decide
you want to know everything possible about
your child so you can do your very best for
it – if there’s a predisposition to pulmonary
disease, you might choose to move to the
country; if there’s a predisposition to high
cholesterol, you might want to make sure
it’s on a low-fat diet.
“So you’re going to subject it to genetic
testing and shape its life a certain way. Who’s
consenting? The child can’t. I would coun-
ter that we already do that. Even withoutknowing the genetics, if we’re aware family
members died in their forties of cardiac dis-
ease, there’s a message there. So what we’re
really doing is further understanding what’s
behind that risk.”HEALTHCARE INEQUALITY
There are plenty more ethical issues. The
expense of genetic testing may mean it
ushers in a whole new era of healthcare
inequality – paying for a blood or saliva
test is one thing, paying for the possible
downstream medical costs associated with
a positive test is quite another.
And the ethics go far beyond healthcare- for instance, what steps will you take if
your child carries the genes that increase
the likelihood of risk-based behaviour such
as committing crime? And what steps might
be taken on a societal level?
The gene monoamine oxidase A – known
as MAOA – has been associated with aggres-
sive, impulsive and criminal behaviour. It
was dubbed “the warrior gene”, with one
controversial New Zealand study in 2007
claiming a version of it was prevalent in
Maori. In his new book, A Brief History of
Everyone Who Ever Lived, British geneticist
Adam Rutherford, who has written and
presented many award-winning BBC pro-
grammes, outlines some of the risks of this
sort of “genetic determinism”.
Not only can it foster prejudice and rein-
force racial stereotypes, but it’s also open to
being used as a defence in criminal trials. In
2009, Tennessee man Davis Bradley Wal-
droup escaped a first-degree murder charge
after slaying his wife’s friend Leslie Bradshaw.
His lawyers claimed he was unable to engage
in the reflection and judgment necessary to
premeditate the crime. At the root of their
defence was the fact he possessed a high-risk
variant of the MAOA gene that, combined
with an abusive childhood, had left him vul-
nerable to becoming a violent adult.
Several studies of the defective MAOA
gene have linked it to an increased risk of
aggression. In one, which used hot chilli
sauce as a method of punishment, those
with the gene were prepared to hand out
the chilli more willingly.
“Bear in mind that according to one of
the studies, one-third of white men carry the
same allele [gene mutation] as those who
murder or fight or dish out hot chilli sauce as
a punishment. Statistically speaking, none
of them will murder,” says Rutherford,
who has concerns about where these links
between biology and violence may take us.
Gillam predicts that
within ive years it will be
possible to sequence an
entire human genome
for less than the cost
of a pizza delivery.