Profile of a Comedienne

Meera - At the end of January Channel 4 and the Wellcome Trust launched an 8-part online miniseries called 'Routes' which saw award-winning comedienne, Katherine Ryan, send a sample of her saliva to a lab in a bid to help her understand what's hidden in her genes.

Katherine - For the routes project I had to spit in a tube and send away my DNA to have a full genome profile done.

Meera - Before you did it how did you feel about having your DNA sequenced? Were you nervous?

Katherine - I was always open to the idea of - I'm not afraid of information. I think that it can only help you. I really was interested to know the result.

Meera - You already knew a little bit about your genetics before you did this, didn't you?

Katherine - Yeah, I've had some bad news already, I guess. I had a melanoma two years ago that was a little bit advanced. I had to have a few surgeries to get rid of that. That's a particularly aggressive form of skin cancer and there are different genes they can test, different markers that might say you'd have a higher probability of getting cancer than someone else. It was just something that I'd love to do to see what else is in there and I'm having a baby this year. I really wanted to see what I might be a carrier of.

Meera - What did you find out?

Katherine - Funny things. I found out that I'm not resistant to malaria or the norovirus. I'm not resistant to AIDS, which is weird. I didn't know anybody was resistant to AIDS! I learned that Lupus [Systemic Lupus Erythematosus] is closely related to coeliac disease, which runs in my family. They're both autoimmune disorders. I have a prostate cancer gene, but I don't have a prostate gland so I'm okay! I don't have schizophrenia or Parkinson's or cystic fibrosis carrier traits. Some good news and bad news all mixed in there. It's a huge profile that you get back. Some of the information was that my eyes are blue, I knew that. I'm very white. I think that some of my ancestry comes from Ireland and nowhere else. It was all very interesting. I add research to it all the time. They compare your results to people with the same background and there's always something new to learn.

Meera - That was comedienne Katherine Ryan discussing her experience of having her genome profiled. How is this profile actually done and how relevant is the information that it provides us with? I met up with Steve Jones, Head of Genetics at University College London to find out, starting with why spit is such a good sample to use.

Steve - To start with it's not really spit. Spit is just an organic liquid. More important is what cells float in it. Cells are what your body is made out of. There are trillions and trillions of cells. That will contain enough cells for them to take off to the lab, take DNA out of it and do this magical sequencing.

Meera - Once a sample has been sent off what actually happens to get a sequence of someone's DNA?

Steve - It's quite a complicated business. There's a whole variety of methods of actually doing it. One way is to basically take a set of molecular scissors which snip, at a particular point, 3 letter sequences. You snip all the way along the DNA into tiny little fragments often overlapping with each other. You look for the overlaps and then rebuild up the whole sequence. That's how you do a DNA sequence. I think what this young lady had done probably wasn't quite a sequence, it was looking at individual points in the DNA to see whether they varied compared to the population as a whole.

Meera - What does looking at particular points or markers in someone's DNA, what can that tell you about someone?

Steve - In some ways looking at a short length of DNA is a bit like looking for a surname. If you look for a surname in the European system it passes from fathers to sons, to grandsons and so on. Any short length of DNA, as long as it's short enough will travel down the generations as a block of letters. By looking at that block of letters you're really sorting out your identity in relation to the other people around you. They look at predetermined points, spots in the DNA which they know varies from person to person, and which quite often we know predisposes to certain inherited conditions, perhaps in association with the environment.

Meera - once someone has their genome sequenced in this way what is the result of this sequencing that they see?

史蒂夫-你可以产生所谓的haplotype which is just a statement of what your identity at particular points of the DNA is. If she's interested in health there are particular genes which predispose to certain diseases. Some are well-known diseases like cystic fibrosis which she'd probably know already if she had but it could possibly tell you that maybe, for example, in order to get lung cancer you need to smoke. You need to have one rather common genetic variant. There was once a hope that you could screen lots and lots of people and tell them I'm afraid you've got the gene that if you smoke you will almost certainly get lung cancer. The hope was it would stop people smoking. It doesn't.

Meera - Some people worry about genome sequencing because they are concerned about finding out what diseases or disorders they might get. Surely it's not just your genetics. Environment also plays an important role, doesn't it?

Steve - There are occasional rare genetic diseases, things like cystic fibrosis that if you've got them really obviously it's the gene that makes a big difference. The environment doesn't make all that much difference. There are many more like heart disease. If you have particular genes it is particularly important for you to avoid a fatty diet, not to get overweight, not to smoke and that kind of stuff. I don't deny this is true. This is certainly true. That's true for everybody.

Meera - Geneticist Steve Jones explaining how Katherine's sample would have been analysed to provide her with her profile of susceptibility and resistance to certain genetic disorders. To find out more about Katherine's experience or play the range of interactive games that Channel 4 have developed to explain the world of genetics visit the roots website at

www.routesgame.com.