Increased frequency of Repeat Expansion Disorders (REDs), genetic profile study on 80,000 people

NEWS - An international team of researchers led by Queen Mary University of London used new bioinformatics techniques to scan the genetic profiles of 80,000 people to understand the frequency of specific expansions of short, repetitive DNA sequences known as Repeat Expansion Disorders (REDs) in the general population.

The study, which explores the most common causes of inherited neurological conditions, suggests that REDs are up to three times more common than previously thought based on clinical observations or disease diagnoses alone. It also found that their frequency is common across different populations.

"This hugely important advance may suggest that Huntington's disease is almost three times more common than we thought. Instead, the presence of certain DNA repeats may not cause the disease in some people," said Arianna Tucci, from Queen Mary University.

It marks a major shift in the way we think about genetic testing, profiling and counselling. The findings were only possible because researchers studied whole genomes from the 100,000 Genomes Project at scale.

It is a paradigm shift from the traditional study of small families with a history of genetic conditions to the analysis of large populations of individuals. The researchers say they will study large groups of people who carry these genetic changes to help better understand what causes them to develop in certain individuals.

"These results are hugely important. They force us as a community of researchers, academics and clinicians to evaluate whether these DNA repeats address an unmet diagnostic need in rare neurological diseases which means that REDs investigations deserve closer attention now," said Sarah Tabrizi, from the UK Dementia Research Institute, UCL, London.

Original research

Ibañez, K., Jadhav, B., Zanovello, M. et al. Increased frequency of repeat expansion mutations across different populations. Nature Medicine (2024). https://doi.org/10.1038/s41591-024-03190-5, DOI:10.1038/s41591-024-03190-5

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