New Scientist - 02.18.2020

12 | New Scientist | 8 February 2020

THE privacy of people who add

their DNA to research databases

may be vulnerable to hackers,

who could exploit the

information published in

genome studies to identify

an individual’s genetic code.

Genetics researchers are

inadvertently publishing

information that can theoretically

be pieced together to identify

someone’s DNA held in a research

or commercial database, say

Daphne Ezer at the Alan Turing

Institute in London and her

colleagues. Her team simulated

how attackers could identify

a person’s genetic code, and

used this method to find a

single dog’s genetic material

in a DNA database.

Genome-wide association

studies (GWAS) identify genes

that are associated with personal

traits or disease. Researchers use

large databases containing the

DNA of hundreds of thousands

of people to conduct these studies

and detect subtle DNA differences

between participants.

Ezer’s team showed how, under

some circumstances, a hacker

could use the information about

an individual’s traits published

in GWAS to recover that person’s

genetic information – known

as a reconstruction attack.

“You might even be able to

identify an individual with just

two studies performed on the

same database, if a small number

of people are included in one

study but not another,” says

Ezer. This could happen if, for

example, some participants

skip a survey question or join

one study later than the other,

which Ezer’s team describe as

a “potentially common” scenario.

In these cases, attackers can

use algorithms to predict the

genetic details of an individual in

one of the studies by combining

information from both. The team

showed this is possible by finding

the genetic information of a single

dog in the Cornell Dog Genome

database (bioRxiv, doi.org/dkx4).

To protect volunteers’ genetic

privacy when publishing the

results of a study, the team

suggests that researchers try

scrambling the data to make

it noisier, or conceal some

identifiable information.

Because the study involved

dogs, we don’t know if a similar

attack would identify people

from their genetic information.

But if used with the technique that

exposed a potential vulnerability

in the genealogy testing website

GEDMatch in October 2019,

“it could potentially be used

to reveal the identities of

individual participants”, says

David Baranger, a neurogenetics

researcher at the University

of Pittsburgh in Pennsylvania.

The UK Biobank, which

holds 500,000 genomes in

its database, says researchers

are prohibited from trying to

identify a participant in this way.

“We are not aware of any such

incident where this has occurred,”

says a spokesperson.

“Researchers treat the privacy

of participants in projects such

as the UK Biobank very seriously,”

says David Curtis at University

College London. ❚

Genetics

Becca Muir

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News

Blood samples are

analysed to produce DNA

data for genome studies

Environment

The seabed is slowly

sinking but it won’t

stop sea level rise

THE weight of water from melting

ice caps is causing the seabed to

sink about 0.1 millimetres a year.

“Greenland and Antarctica are

melting much faster [than they

were previously], so we can expect

much higher ocean deformation

in the future,” says Bramha Dutt

Vishwakarma at the University

of Bristol in the UK.

He and his colleagues calculated

how much the extra mass in the

ocean is pushing down the sea

floor, and what this means for sea

levels. They found that it will have

only a tiny effect on future sea level

rise because the oceans are rising

about 3 millimetres per year – far

faster than the seabed is sinking

(Geophysical Research Letters,

doi. org/dkvv).

Sea level rise is due to climate

change, which is in turn driven

by our greenhouse gas emissions.

Forecasts for 21st-century sea level

rise vary between 1 and 2 metres.

As the climate warms, so does

seawater, and when water warms

it expands, causing the sea to rise.

In the 20th century, this thermal

expansion was the main driver of

sea level rise, says Jonathan Bamber

at the University of Bristol, who

collaborated on the work. As a

result, the mass of the oceans

stayed about the same, even as

their volume grew.

Now, a warmer climate is

melting the ice in glaciers and

the great ice caps, causing more

water to flow into the sea. That

is steadily increasing the mass

of the oceans and pressing the

seabed downwards.

Both Vishwakarma and Bamber

emphasise that the finding will

make no meaningful difference

to future sea level rise. While the

sinking seabed will slow sea level

rise, the effect is too small to be

meaningful because the seabed is

sinking about 30 times more slowly

than sea levels are rising. ❚

Michael Marshall

Sea levels

are forecast

to rise between

1 and 2 metres

this century

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Privacy of genetic research

volunteers may be at risk