Institute of Genetics and Cancer

Lothian Birth Cohort study suggests ageing process accelerated by DNA changes

MRC Human Genetics Unit and Centre for Genomic and Experimental Medicine study with University of Glasgow links somatic mutations to a general measure of biological ageing: August 2019

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DNA remains largely unchanged throughout a person’s life. However, a small number of alterations occur as we age, called somatic mutations. If somatic mutations occur at distinct genes they can change the way blood stem cells operate. This has been associated with blood cancers and can contribute to heart conditions.

A recent study by scientists at the University Glasgow and the University of Edinburgh – including the MRC Human Genetics Unit and the Centre for Genomic and Experimental Medicine - suggests that these DNA changes are also linked to a general measure of biological ageing that associates with a variety of age-related diseases. 

The team studied more than 1,000 older people in the Lothian Birth Cohorts – two groups of people born in 1921 and 1936 who have been followed over many years - to investigate how cognitive abilities and the brain change as we age, and which lifestyle, health and genetic factors influence these changes. This unique group of people, now in their 80s and 90s, are one of the most-intensively studied groups in the world.

Within this cohort, the research team measured where biological age deviates from chronological age by looking at small modifications on the DNA molecule which change gradually over time. They found that the study participants who presented with somatic mutations (around 6% of individuals) had a biological age around 4 years older than those with no somatic mutations.  

Future studies are now being planned to see if these somatic mutations make individuals more susceptible to ageing-related diseases such as cancer, dementia and cardiovascular disease. The research team are also exploring potential reasons why these acquired DNA changes are linked to biological ageing.

Somatic mutations have mostly been studied in cancer. Our finding adds evidence that they play a role in other diseases, which will change the way we study disease risk.

Dr Tamir ChandraGroup Leader at the MRC Human Genetics