£20 million study comparing the epigenetics of twins launched

Scientists from the UK and China are collaborating to study epigenetic signatures that mark the differences between 5,000 twins. Those affected by diabetics and osteoporosis are just some of the people who could benefit from the £20 million 'Epitwin' project.

Epigenetics explores DNA methylation  changes that accumulate on DNA, which can affect gene expression, and are thought to potentially influence health outcomes.

The researchers will be examining differences in DNA methylation at 20 million sites (called CpG islands) in the DNA of twins who share identical DNA sequences, and will be looking for differences that explain why many identical twins do not develop the same diseases. The project will focus initially on obesity, diabetes, allergies, heart disease, osteoporosis and longevity, but researchers say the method can be applied to every common trait or disease. The team is ultimately aiming to identify therapeutic targets for the development of novel drugs.

Tim Spector, Director of TwinsUK and Professor of Genetic Epidemiology at King's College London, who is the co-leader of the project said: 'Finding the crucial differences between twins will lead us to the key genes that are being turned on and off, and so to the cause of disease, with great potential to find key targets for drug treatment'.

'The fact that twins are such a marvellous natural experiment, combined with the hundreds of disease details and traits on the twins that we have collected over 17 years, offer a unique study opportunity', he said. 'So far this type of study has only been attempted on a handful of twins, so we want to scale it up - one thousand fold'.

Professor Jun Wang, Executive Director of BGI (China) and co-leader of the project said: 'Epigenetics is one of our major targets for the next five years - and this combination of our technology and resources with the unique twin resource will provide the world with an unprecedented dataset. We hope to unlock many secrets about human genetics that we don't currently understand, and to accelerate research and applications in human healthcare'.

Investigating patterns of DNA methylation is much harder than simply sequencing DNA because patterns of methylation vary substantially between different tissues in the same organism, and also according to its developmental stage. Professor Wang's team has already sequenced the genomes of a number of organisms, including Giant Pandas, rice and silkworms.

Dr Manel Esteller, a geneticist at the Spanish National Cancer Centre in Madrid, says he is impressed by the ambition of the project, adding that he does not envy the task of analysing and interpreting the 'huge amount of data', which represents 'a lot of bioinformatic effort'.