BBC Knowledge 2017 02

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UPERHEROES are everywhere

right now. Righting wrongs,

saving planets and generally

punching each other senseless in films,

comic books and TV shows. But just as

Clark Kent wanders unrecognised

through the world, only turning into

Superman when his help is needed,

there are genetic superheroes dwelling

among us, and, in most cases, they’re

completely unaware of their amazing

powers. Only now, by trawling

through the DNA of thousands of

people, are we discovering their

hidden identities.

Gaulty genes

Dr Cisca Wijmenga and her team at

the University of Groningen in the

Netherlands never set out to find

superheroes. Their project was

important but unexciting: reading

the DNA of 250 Dutch families to

establish a baseline for the genetic

make-up of the country. Then, as

future studies turned up interesting

gene variations and faults (mutations)

linked to disease, they would be able to

tell if they were genuinely responsible

for causing illness or just part of the

underlying DNA of Dutchness.

Then they found them.

Two unlikely heroes, both in their

sixties and both carrying two faulty

copies of a gene called SERPIN A1

(we usually have two copies of every

gene, one from mum and the other

from dad). This particular gene

normally makes a protein that helps

to protect the tubes and air sacs in the

lungs. Without it, these delicate

structures start to break down, causing

serious breathing problems by 30 to

40 years of age. But these two

individuals had both made it into

their sixties without suffering from

any severe lung problems.

And there was more. Wijmenga

points to other examples in the data,

such as the 177 people in her study

who should by rights have a genetic

disease called pseudoachondroplasia.

The condition leads to unusually short

stature and joint pains. But most of

the individuals were just fine.

The list goes on: Wolfram syndrome

(high blood sugar, sight and hearing

loss); Wilson disease (liver problems

and psychiatric issues); Niemann-Pick

disease (nerve problems and failure

to grow properly in childhood),

| GENETICS

SCIENCE

78 February 2017

There are hundreds of healthy

Dutch people going about their

daily lives, defying the faulty

genes within them

72 February 2017