The Epigenetics Revolution

Nessa Carey The Epigenetics Revolution

For Abi Reynolds, who reprogrammed my life

And in memory of Sean Carey, 1925 to 2011

Acknowledgements

Over the last few years I’ve had the privilege of working with some truly amazing scientists. There are too many to name here but special acknowledgements must go to Michelle Barton, Stephan Beck, Mark Bedford, Shelley Berger, Adrian Bird, Chris Boshoff, Sharon Dent, Didier Devys, Luciano Di Croce, Anne Ferguson-Smith, Jean-Pierre Issa, Peter Jones, Bob Kingston, Tony Kouzarides, Peter Laird, Jeannie Lee, Danesh Moazed, Steve McMahon, Wolf Reik, Ramin Shiekhattar, Irina Stancheva, Azim Surani, Laszlo Tora, Bryan Turner and Patrick Varga-Weisz.

Thanks go also to my former colleagues at CellCentric – Jonathan Best, Devanand Crease, Tim Fell, David Knowles, Neil Pegg, Thea Stanway and Will West.

As a first-time author I owe major gratitude to my agent, Andrew Lownie, for taking a risk on me and on this book.

Major thanks also to the lovely people at my publishers Icon, especially Simon Flynn, Najma Finlay, Andrew Furlow, Nick Halliday and Harry Scoble. Their unfailing patience with my complete ignorance of all aspects of publishing has been heroic.

I’ve had great support from family and friends and I hope they’ll forgive me for not mentioning them all by name. But for sheer entertainment and distraction during some stressy patches I have to thank Eleanor Flowerday, Willem Flowerday, Alex Gibbs, Ella Gibbs, Jessica Shayle O’Toole, Lili Sutton and Luke Sutton.

And for always resisting the temptation to roll her eyes every time I said, ‘I can’t meet friends/do the dishes/go away for the weekend because I’m working on my book’, I’ve got to thank my lovely partner Abi Reynolds. I promise I’ll take that ballroom dancing lesson now.

Introduction

DNA.

Sometimes, when we read about biology, we could be forgiven for thinking that those three letters explain everything. Here, for example, are just a few of the statements made on 26 June 2000, when researchers announced that the human genome had been sequenced[1]:

Today we are learning the language in which God created life.

US President Bill Clinton

We now have the possibility of achieving all we ever hoped for from medicine.

UK Science Minister Lord Sainsbury

Mapping the human genome has been compared with putting a man on the moon, but I believe it is more than that. This is the outstanding achievement not only of our lifetime, but in terms of human history.

Michael Dexter, The Wellcome Trust

From these quotations, and many others like them, we might well think that researchers could have relaxed a bit after June 2000 because most human health and disease problems could now be sorted out really easily. After all, we had the blueprint for humankind. All we needed to do was get a bit better at understanding this set of instructions, so we could fill in a few details.

Unfortunately, these statements have proved at best premature. The reality is rather different.

We talk about DNA as if it’s a template, like a mould for a car part in a factory. In the factory, molten metal or plastic gets poured into the mould thousands of times and, unless something goes wrong in the process, out pop thousands of identical car parts.

But DNA isn’t really like that. It’s more like a script. Think of Romeo and Juliet, for example. In 1936 George Cukor directed Leslie Howard and Norma Shearer in a film version. Sixty years later Baz Luhrmann directed Leonardo DiCaprio and Claire Danes in another movie version of this play. Both productions used Shakespeare’s script, yet the two movies are entirely different. Identical starting points, different outcomes.

That’s what happens when cells read the genetic code that’s in DNA. The same script can result in different productions. The implications of this for human health are very wide-ranging, as we will see from the case studies we are going to look at in a moment. In all these case studies it’s really important to remember that nothing happened to the DNA blueprint of the people in these case studies. Their DNA didn’t change (mutate), and yet their life histories altered irrevocably in response to their environments.