Life as a twin-ea pig: Back to the Twin Research Unit

I fell on the four-finger KitKat like a woman possessed. It was nearly 8 hours since my sister and I had eaten. In the meantime, we’d been scanned, weighed, measured and bled. Never had chocolate tasted so good.

Nearly four years ago, we found ourselves in a similar situation. The room may be in a different part of St Thomas’ Hospital, London, but many other things were the same today as on our last visit to the Twin Research Unit.

Before we could be released into the fabled Room With Biscuits, we had to be bled and scanned. While one of us attempted to stay still and quiet for seven minutes as the DXA scanner measured our bone density, the other was bled into a rainbow-lidded array of blood containers. Research Assistants Dimitrios, Ayrun and Abhishek worked through piles of questionnaires and consent forms, ticking off each test as we completed it.

While I lie motionless under the DXA’s invisible X-ray beams, my sister is writing in my notebook. She is already irritated that I can be scanned pretty much fully dressed, having deliberately selected metal-free clothing for our visit. Her hypoglycaemic ramblings include:

 I am contemplating gnawing away at the tabletop.

 Seven minutes of stillness required. Just as well she is taped to the bed.

 After the hip DXA, C is asked to ‘wibble’ around to align her spine while resting her legs on a massive blue box. The investigator fears she has metal down her pants.

 WHY DIDN’T I WEAR LEGGINGS TOO?

Last time we were here, childhood rivalries were reignited. The researchers pitted us against each other to see who could hold their arm under a thermal lamp the longest, the temperature creeping up degree by degree. This time, alas, no pain test was required.

The ominous-sounding ‘pain machine’ was not operated on this visit…

Never fear though, twin researchers are always after a different metric, piece of information or actual part of you to extract. This time, for example, we had hairs pulled out of our scalps from the root. During four of the hottest days of the year we were forbidden to get our backs wet because we were wearing a skin patch to test for contact allergies.

The patch was a piece of medical tape about the size of a smartphone and was impregnated with a variety of allergens or allergen mixes, including the exotic-sounding “Balsam of Peru” and slightly less nice “colophony”. The results of this sticky mess revealed that we are both allergic to nickel, and that trying to “avoid excessive sweating” in 90-degree heat is easier than a medical advice leaflet makes it sound. My back is still itching.

The itching, fasting and bleeding are all in aid of the TwinsUK Bioresource, a collection of biological samples and information on health, characteristics and behaviour from nearly 9000 twins of the 12 000 UK twins the Unit has registered on its  books. The resource is maintained by the 75 or so research nurses, lab personnel, statisticians, academic researchers and support staff who work in the Unit’s new offices. When I visit, a gentle office burble rises from the desks, which are surrounded by lime green walls and amazing views of Westminster and the river Thames.

“As you found out on your visit, the twins have a range of different assessments, which can be for a number of different studies,” says Senior Research Nurse Liisa Bevan, who’s worked in the department for 10 years. The major projects underway include a study into allergies, and another looking at the effects of an urban environment on genetics, which is funded by the hospital’s National Institutes of Health Research Biomedical Research Centre. This latter study has an additional aim of trying to recruit more twins from black and ethnic minority backgrounds, who currently make up approximately 2% of the volunteers.

Some of the paperwork we completed before our latest trip to the Twin Research Unit

Research over the 20 years the Unit has been running have shed light on the genetic bases of diseases of ageing as well as other behaviours and characteristics. The twin data has use beyond studies into heritability too, and the Unit works with scientific collaborators from a variety of fields. For example, anonymised data from the twin database is being used to provide healthy controls for the UK10K study, a UK-based project that is being carried out to identify the rare genetic variants implicated in disease.

The Wellcome Trust has supported the Unit since its launch in 1992 and has just awarded its researchers a Biomedical Resources Grant. “This new funding allows us to open up the resource even more to other collaborators,” says Gail Clement, the Unit’s Research Nurse Manager. “More groups will be able to use our data, use our samples, see the twins, or request that we collect specific data from the twins.”

The potential is great: for example, there are some 250 000 biological samples collected by the Unit’s researchers that need checking, labelling and storage before they can be made available to other groups.

Meanwhile, my sister is reeling from the news that our under-average ability to grip (first identified in 2008) has not improved. “But I grip things all day at work,” she cries, waving a clawed hand manically in the air. “Never mind,” I console her. “Have another KitKat.”

• Next year, the Twin Research Unit will be 21. Do you want to design a new logo for the Unit’s birthday year? Find out more here. Hurry – the competition closes on 15 August 2012.