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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New living fossil, Amethyst worm lizard (Amphisbaena amethysta), from Espinhaço Mountain Range, Brazil

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Early human species inhabited highlands for availability and diversity of food

NEWS - Researchers at the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea suggest that the patchwork of ecosystems found in mountainous regions played a key role in human evolution. Using a vast dataset of fossils, artifacts, high-resolution landscapes and 3 million-year-long simulations of Earth’s climate, a team of scientists is painting a clearer picture of how and why early humans adapted to rugged landscapes. Hominins are often found in and near mountainous regions. Now Elke Zeller and Axel Timmermann have helped explain why so many of our evolutionary relatives preferred to be “highlanders” rather than “lowlanders.” Mountainous regions are rich in biodiversity, providing a range of environmental conditions in which different species of plants and animals thrive. Steep areas typically exhibit a greater diversity, density of ecosystems and vegetation types, known as biomes. This diversity of biomes was attractive to early humans because it provided

Black-spotted longnose gudgeon (Microphysogobio punctatus) as new species and M. elongatus as synonym of M. tungtingensis

NEWS - Researchers have established the black-spotted longnose gudgeon ( Microphysogobio punctatus ) as a new species and redescribed M. elongatus (Yao & Yang, 1977) as a junior synonym of M. tungtingensis (Nichols, 1926) based on morphological analysis and molecular evidence supported by mitochondrial gene sequences. M. tungtingensis has been considered valid since its description, but its morphology is still vague especially when compared to another similar species, M. elongatus . In this study, researchers examined both species and compared several lots of specimens from a wide geographical range. There was no significant morphological difference between the two. Molecular evidence supported by mitochondrial gene sequences also showed low genetic distance and suggested that M. elongatus is a junior synonym of M. tungtingensis . At the same time, M. punctatus was found to have a similar distribution to both. M. punctatus is distributed in the Guijiang and Liujiang rivers, t

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