ֱ̽ of Cambridge - genetics /taxonomy/subjects/genetics en Genetic study reveals hidden chapter in human evolution /research/news/genetic-study-reveals-hidden-chapter-in-human-evolution <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/gettyimages-506356472-dp.jpg?itok=oPsh3EiG" alt="Plaster reconstructions of the skulls of human ancestors" title="Plaster reconstructions of the skulls of human ancestors, Credit: Jose A Bernat Bacete via Getty Images" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Using advanced analysis based on full genome sequences, researchers from the ֱ̽ of Cambridge have found evidence that modern humans are the result of a genetic mixing event between two ancient populations that diverged around 1.5 million years ago. About 300,000 years ago, these groups came back together, with one group contributing 80% of the genetic makeup of modern humans and the other contributing 20%.</p> <p>For the last two decades, the prevailing view in human evolutionary genetics has been that Homo sapiens first appeared in Africa around 200,000 to 300,000 years ago, and descended from a single lineage. However, these latest <a href="https://www.nature.com/articles/s41588-025-02117-1">results</a>, reported in the journal <em>Nature Genetics</em>, suggest a more complex story.</p> <p>“ ֱ̽question of where we come from is one that has fascinated humans for centuries,” said first author Dr Trevor Cousins from Cambridge’s Department of Genetics. “For a long time, it’s been assumed that we evolved from a single continuous ancestral lineage, but the exact details of our origins are uncertain.”</p> <p>“Our research shows clear signs that our evolutionary origins are more complex, involving different groups that developed separately for more than a million years, then came back to form the modern human species,” said co-author Professor Richard Durbin, also from the Department of Genetics.</p> <p>While earlier research has already shown that Neanderthals and Denisovans – two now-extinct human relatives – interbred with Homo sapiens around 50,000 years ago, this new research suggests that long before those interactions – around 300,000 years ago – a much more substantial genetic mixing took place. Unlike Neanderthal DNA, which makes up roughly 2% of the genome of non-African modern humans, this ancient mixing event contributed as much as 10 times that amount and is found in all modern humans.</p> <p> ֱ̽team’s method relied on analysing modern human DNA, rather than extracting genetic material from ancient bones, and enabled them to infer the presence of ancestral populations that may have otherwise left no physical trace. ֱ̽data used in the study is from the 1000 Genomes Project, a global initiative that sequenced DNA from populations across Africa, Asia, Europe, and the Americas.</p> <p> ֱ̽team developed a computational algorithm called cobraa that models how ancient human populations split apart and later merged back together. They tested the algorithm using simulated data and applied it to real human genetic data from the 1000 Genomes Project.</p> <p>While the researchers were able to identify these two ancestral populations, they also identified some striking changes that happened after the two populations initially broke apart.</p> <p>“Immediately after the two ancestral populations split, we see a severe bottleneck in one of them—suggesting it shrank to a very small size before slowly growing over a period of one million years,” said co-author Professor Aylwyn Scally, also from the Department of Genetics. “This population would later contribute about 80% of the genetic material of modern humans, and also seems to have been the ancestral population from which Neanderthals and Denisovans diverged.”</p> <p> ֱ̽study also found that genes inherited from the second population were often located away from regions of the genome linked to gene functions, suggesting that they may have been less compatible with the majority genetic background. This hints at a process known as purifying selection, where natural selection removes harmful mutations over time.</p> <p>“However, some of the genes from the population which contributed a minority of our genetic material, particularly those related to brain function and neural processing, may have played a crucial role in human evolution,” said Cousins.</p> <p>Beyond human ancestry, the researchers say their method could help to transform how scientists study the evolution of other species. In addition to their analysis of human evolutionary history, they applied the cobraa model to genetic data from bats, dolphins, chimpanzees, and gorillas, finding evidence of ancestral population structure in some but not all of these.</p> <p>“What’s becoming clear is that the idea of species evolving in clean, distinct lineages is too simplistic,” said Cousins. “Interbreeding and genetic exchange have likely played a major role in the emergence of new species repeatedly across the animal kingdom.”</p> <p>So who were our mysterious human ancestors? Fossil evidence suggests that species such as Homo erectus and Homo heidelbergensis lived both in Africa and other regions during this period, making them potential candidates for these ancestral populations, although more research (and perhaps more evidence) will be needed to identify which genetic ancestors corresponded to which fossil group.</p> <p>Looking ahead, the team hopes to refine their model to account for more gradual genetic exchanges between populations, rather than sharp splits and reunions. They also plan to explore how their findings relate to other discoveries in anthropology, such as fossil evidence from Africa that suggests early humans may have been far more diverse than previously thought.</p> <p>“ ֱ̽fact that we can reconstruct events from hundreds of thousands or millions of years ago just by looking at DNA today is astonishing,” said Scally. “And it tells us that our history is far richer and more complex than we imagined.”</p> <p> ֱ̽research was supported by Wellcome. Aylwyn Scally is a Fellow of Darwin College, Cambridge. Trevor Cousins is a member of Darwin College, Cambridge.</p> <p> </p> <p><em><strong>Reference:</strong><br /> Trevor Cousins, Aylwyn Scally &amp; Richard Durbin. ‘<a href="https://www.nature.com/articles/s41588-025-02117-1">A structured coalescent model reveals deep ancestral structure shared by all modern humans</a>.’ Nature Genetics (2025). DOI: 10.1038/s41588-025-02117-1</em></p> </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Modern humans descended from not one, but at least 2 ancestral populations that drifted apart and later reconnected, long before modern humans spread across the globe.</p> </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">Our history is far richer and more complex than we imagined</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Aylwyn Scally</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="https://www.gettyimages.co.uk/detail/photo/reconstruction-with-plasters-to-royal-scale-of-royalty-free-image/506356472" target="_blank">Jose A Bernat Bacete via Getty Images</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Plaster reconstructions of the skulls of human ancestors</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License." src="/sites/www.cam.ac.uk/files/inner-images/cc-by-nc-sa-4-license.png" style="border-width: 0px; width: 88px; height: 31px;" /></a><br /> ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Images, including our videos, are Copyright © ֱ̽ of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our <a href="/">main website</a> under its <a href="/about-this-site/terms-and-conditions">Terms and conditions</a>, and on a <a href="/about-this-site/connect-with-us">range of channels including social media</a> that permit your use and sharing of our content under their respective Terms.</p> </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div> Tue, 18 Mar 2025 10:00:00 +0000 sc604 248776 at Scientists identify genes that make humans and Labradors more likely to become obese /research/news/scientists-identify-genes-that-make-humans-and-labradors-more-likely-to-become-obese <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/news/labrador-licking-nose-credit-james-barker-on-unsplash-885x428.jpg?itok=_DKNIeBp" alt="Labrador licking nose" title="Labrador licking nose, Credit: James Barker on Unsplash" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Researchers studying British Labrador retrievers have identified multiple genes associated with canine obesity and shown that these genes are also associated with obesity in humans.  </p> <p> ֱ̽dog gene found to be most strongly associated with obesity in Labradors is called DENND1B. Humans also carry the DENND1B gene, and the researchers found that this gene is also linked with obesity in people.  </p> <p>DENND1B was found to directly affect a brain pathway responsible for regulating the energy balance in the body, called the leptin melanocortin pathway.  </p> <p>An additional four genes associated with canine obesity, but which exert a smaller effect than DENND1B, were also mapped directly onto human genes. </p> <p>“These genes are not immediately obvious targets for weight-loss drugs, because they control other key biological processes in the body that should not be interfered with.</p> <p>But the results emphasise the importance of fundamental brain pathways in controlling appetite and body weight,” said Alyce McClellan in the ֱ̽ of Cambridge’s Department of Physiology, Development and Neuroscience, and joint first author of the report.</p> <p>“We found that dogs at high genetic risk of obesity were more interested in food,” said Natalie Wallis in the ֱ̽ of Cambridge’s Department of Physiology, Development and Neuroscience, and joint first author of the report.</p> <p>She added: “We measured how much dogs pestered their owners for food and whether they were fussy eaters. Dogs at high genetic risk of obesity showed signs of having higher appetite, as has also been shown for people at high genetic risk of obesity.”</p> <p> ֱ̽study found that owners who strictly controlled their dogs’ diet and exercise managed to prevent even those with high genetic risk from becoming obese - but much more attention and effort was required.</p> <p>Similarly, people at high genetic risk of developing obesity will not necessarily become obese, if they follow a strict diet and exercise regime - but they are more prone to weight gain.</p> <p>As with human obesity, no single gene determined whether the dogs were prone to obesity; the net effect of multiple genetic variants determined whether dogs were at high or low risk.</p> <p> ֱ̽results were <a href="http://doi.org/10.1126/science.ads2145">published on 6 March in the journal 'Science'</a>.</p> <p>“Studying the dogs showed us something really powerful: owners of slim dogs are not morally superior. ֱ̽same is true of slim people. If you have a high genetic risk of obesity, then when there’s lots of food available you’re prone to overeating and gaining weight unless you put a huge effort into not doing so,” said Dr Eleanor Raffan, a researcher in the ֱ̽ of Cambridge’s Department of Physiology, Development and Neuroscience who led the study. </p> <p>She added: “By studying dogs we could measure their desire for food separately to the control owners exerted over their dog’s diet and exercise. In human studies, it’s harder to study how genetically driven appetite requires greater willpower to remain slim, as both are affecting the one person.” </p> <p> ֱ̽current human obesity epidemic is mirrored by an obesity epidemic in dogs. About 40-60% of pet dogs are overweight or obese, which can lead to a range of health problems. </p> <p>Dogs are a good model for studying human obesity: they develop obesity through similar environmental influences as humans, and because dogs within any given breed have a high degree of genetic similarity, their genes can be more easily linked to disease. </p> <p>To get their results, the researchers recruited owners with pet dogs in which they measured body fat, scored ‘greediness’, and took a saliva sample for DNA. Then they analysed the genetics of each dog. By comparing the obesity status of the dog to its DNA, they could identify the genes linked to canine obesity. <br /> Dogs carrying the genetic variant most associated with obesity, DENND1B, had around 8% more body fat than those without it.  </p> <p> ֱ̽researchers then examined whether the genes they identified were relevant to human obesity. They looked at both large population-based studies, and at cohorts of patients with severe, early onset obesity where single genetic changes are suspected to cause the weight gain.  </p> <p> ֱ̽researchers say owners can keep their dogs distracted from constant hunger by spreading out each daily food ration, for example by using puzzle feeders or scattering the food around the garden so it takes longer to eat, or by choosing a more satisfying nutrient composition for their pets. </p> <p>Raffan said: “This work shows how similar dogs are to humans genetically. Studying the dogs meant we had reason to focus on this particular gene, which has led to a big advance in understanding how our own brain controls our eating behaviour and energy use.”  </p> <p> ֱ̽research was funded by Wellcome, the BBSRC, Dogs Trust, Morris Animal Foundation, MRC, France Genomique consortium, European Genomic Institute for Diabetes, French National Center for Precision Diabetic Medicine, Royal Society, NIHR, Botnar Foundation, Bernard Wolfe Health Neuroscience Endowment, Leducq Fondation, Kennel Club Charitable Trust. </p> <p><strong>Reference</strong><br /> <em>Wallis, N J et al: ‘<a href="http://doi.org/10.1126/science.ads2145">Canine genome-wide association study identifies DENND1B as an obesity gene in dogs and humans</a>.’ Science, March 2025. DOI: 10.1126/science.ads2145</em></p> </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Researchers at the ֱ̽ of Cambridge have discovered genes linked to obesity in both Labradors and humans. They say the effects can be over-ridden with a strict diet and exercise regime.</p> </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">Dogs at high genetic risk of obesity showed signs of having higher appetite, as has also been shown for people at high genetic risk of obesity.</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Natalie Wallis</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/" target="_blank">James Barker on Unsplash</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Labrador licking nose</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License." src="/sites/www.cam.ac.uk/files/inner-images/cc-by-nc-sa-4-license.png" style="border-width: 0px; width: 88px; height: 31px;" /></a><br /> ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Images, including our videos, are Copyright © ֱ̽ of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our <a href="/">main website</a> under its <a href="/about-this-site/terms-and-conditions">Terms and conditions</a>, and on a <a href="/about-this-site/connect-with-us">range of channels including social media</a> that permit your use and sharing of our content under their respective Terms.</p> </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div><div class="field field-name-field-license-type field-type-taxonomy-term-reference field-label-above"><div class="field-label">Licence type:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/imagecredit/attribution-noncommerical">Attribution-Noncommerical</a></div></div></div> Thu, 06 Mar 2025 19:03:04 +0000 jg533 248738 at Back to BRCA: the discovery of a breast cancer risk gene /stories/30-years-since-BRCA1 <div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>In 1994, a landmark paper identified a gene – BRCA1 – that significantly increases the risk of breast and ovarian cancers when faulty. Thirty years on, we look at the major impact it has had on how we understand and treat cancer – and why there is still much to learn.</p> </p></div></div></div> Mon, 07 Oct 2024 08:00:50 +0000 cjb250 247911 at ֱ̽master of mutations /stories/dr-alex-cagan <div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Dr Alex Cagan – illustrator, geneticist and explorer of animal DNA – is offering a new perspective on the tapestry of life. His work has profound implications for the pursuit of healthy ageing and the possibilities of cancer resistance.</p> </p></div></div></div> Mon, 29 Jul 2024 13:39:02 +0000 lkm37 247171 at New genetic test will eliminate a form of inherited blindness in dogs /research/news/new-genetic-test-will-eliminate-a-form-of-inherited-blindness-in-dogs <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/english-shepherd-puppy-2-885x428_0.jpg?itok=RB41ipdC" alt="English Shepherd puppy" title="English Shepherd puppy, Credit: None" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Progressive retinal atrophy (PRA) is a group of inherited diseases that causes progressive degeneration of the light sensitive cells at the back of the eye. Dogs with PRA have normal sight at birth, but by the age of four or five they will be totally blind. There is no treatment.</p> <p>Now a team led by the ֱ̽ of Cambridge has identified the genetic mutation that causes PRA in English Shepherd Dogs, and developed a DNA test for it. By identifying dogs carrying the disease before their eyesight starts to fail, this provides a tool to guide breeding decisions so the disease is not passed on to puppies.</p> <p>Owners usually don’t realise their dog has PRA until it is middle-aged, by which time it might have bred, and passed on the faulty gene to its puppies. This has made it a difficult disease to control.</p> <p> ֱ̽new discovery means that progressive retinal atrophy can now be completely eliminated from the English Shepherd Dog population very quickly.</p> <p> ֱ̽results are <a href="https://www.mdpi.com/2073-4425/15/7/952">published today in the journal <em>Genes</em></a>.</p> <p>“Once the dog’s eyesight starts to fail there’s no treatment – it will end up totally blind,” said Katherine Stanbury, a researcher in the ֱ̽ of Cambridge’s Department of Veterinary Medicine and first author of the report.</p> <p>She added: “Now we have a DNA test, there’s no reason why another English Shepherd Dog ever needs to be born with this form of progressive retinal atrophy – it gives breeders a way of totally eliminating the disease.”</p> <p> ֱ̽genetic mutation identified by the team is recessive, which means it only causes blindness if the English Shepherd Dog inherits two copies of it. If the dog only has one copy this makes it a carrier – it will not develop PRA but can pass the mutation on to its puppies. If two carriers are bred together, about one in four of the puppies will be affected with PRA.</p> <p>Dogs breeds are very inbred, so many individuals are related – giving them a much higher chance of being affected by recessive diseases than humans.</p> <p> ֱ̽team began the research after being contacted by a distraught owner of an English Shepherd Dog that had been recently diagnosed with PRA. ֱ̽dog had been working as a search and rescue dog but had to retire due to visual deterioration that has resulted in total blindness. ֱ̽researchers put out a call for DNA samples from other owners or breeders of this breed, and received samples from six English Shepherds with PRA and twenty without it. This was enough for them to pinpoint the genetic mutation responsible for PRA using whole genome sequencing.</p> <p> ֱ̽team offers a <a href="https://www.cagt.co.uk/">commercial canine genetic testing service</a> providing DNA tests to dog breeders to help them avoid breeding dogs that will develop inherited diseases. As part of this they will now offer a DNA test for Progressive Retinal Atrophy in English Shepherds. Anyone can buy a testing kit, costing just £48, to take a swab from inside their dog’s mouth and send it back for testing.</p> <p>“An owner won't necessarily notice their dog has got anything wrong with its eyes until it starts bumping into the furniture. Unlike humans who will speak up if their sight isn’t right, dogs just have to get on with things,” said Dr Cathryn Mellersh in the ֱ̽ of Cambridge’s Department of Veterinary Medicine, senior author of the report.</p> <p>She added: “For the price of a decent bag of dog food people can now have their English Shepherd tested for Progressive Retinal Atrophy prior to breeding. It’s about prevention, rather than a cure, and it means a huge amount to the people who breed these dogs. They no longer need to worry about whether the puppies are going to be healthy or are going to develop this horrible disease in a few years’ time.”</p> <p> ֱ̽English Shepherd is a breed of herding dog popular in the United States and is closely related to the Border Collie.</p> <p> ֱ̽new discovery is the thirty-third genetic mutation causing an inherited disease in dogs that the team has found – twenty-three of which cause eye diseases. They say that the health and wellbeing of many dogs has been compromised because of how they have been bred by humans.</p> <p>PRA occurs in many dog breeds including the English Shepherd Dog. And it is similar to a disease called retinitis pigmentosa in humans, which also causes blindness. ֱ̽researchers say that their work with dogs could shed light on the human version of the disease and potentially identify targets for gene therapy in the future.</p> <p> ֱ̽work was carried out in collaboration with <a href="https://www.wisdompanel.com/en-gb">Wisdom Panel</a>, Mars Petcare, as part of the <a href="https://www.canine-genetics.org.uk/research/criedd/#:~:text=The%20consortium%20to%20research%20inherited,screening%20tools%20for%20these%20mutations">Consortium to Research Inherited Eye Diseases in Dogs</a> (CRIEDD), with funding from the Dog’s Trust and the Kennel Club Charitable Trust.</p> <p><em>Reference: Stanbury, K. et al, ‘<a href="https://www.mdpi.com/2073-4425/15/7/952">Exonic SINE insertion in FAM161A is associated with autosomal recessive progressive retinal atrophy in the English Shepherd.</a>’ July 2024.</em></p> <p><a href="https://www.philanthropy.cam.ac.uk/story/going-to-the-dogs"><strong>FIND OUT MORE AND SUPPORT THIS RESEARCH</strong></a></p> </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Cambridge scientists have identified the genetic mutation that causes progressive retinal atrophy in English Shepherd Dogs, which results in incurable blindness, and developed a genetic test to help eliminate the disease from future generations of the breed.</p> </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">Now we have a DNA test, there’s no reason why another English Shepherd Dog ever needs to be born with this form of progressive retinal atrophy – it gives breeders a way of totally eliminating the disease.</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Katherine Stanbury</div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">English Shepherd puppy</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License." src="/sites/www.cam.ac.uk/files/inner-images/cc-by-nc-sa-4-license.png" style="border-width: 0px; width: 88px; height: 31px;" /></a><br /> ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Images, including our videos, are Copyright © ֱ̽ of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our <a href="/">main website</a> under its <a href="/about-this-site/terms-and-conditions">Terms and conditions</a>, and on a <a href="/about-this-site/connect-with-us">range of channels including social media</a> that permit your use and sharing of our content under their respective Terms.</p> </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div> Sun, 21 Jul 2024 23:38:11 +0000 jg533 247041 at Scientists identify rare gene variants that confer up to 6-fold increase in risk of obesity /research/news/scientists-identify-rare-gene-variants-that-confer-up-to-6-fold-increase-in-risk-of-obesity <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/food-washing-as3a9470.jpg?itok=E31miRia" alt="Woman with obesity washing food" title="Woman with obesity washing food, Credit: World Obesity Federation" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p> ֱ̽discovery of rare variants in the genes BSN and APBA1 are some of the first obesity-related genes identified for which the increased risk of obesity is not observed until adulthood.</p> <p> ֱ̽study, published in <em>Nature Genetics</em>, was led by researchers at the Medical Research Council (MRC) Epidemiology Unit and the MRC Metabolic Diseases Unit at the Institute of Metabolic Science, both based at the ֱ̽ of Cambridge.</p> <p> ֱ̽researchers used UK Biobank and other data to perform whole exome sequencing of body mass index (BMI) in over 500,000 individuals.</p> <p>They found that genetic variants in the gene BSN, also known as Bassoon, can raise the risk of obesity as much as six times and was also associated with an increased risk of non-alcoholic fatty liver disease and of type 2 diabetes.</p> <p> ֱ̽Bassoon gene variants were found to affect 1 in 6,500 adults, so could affect about 10,000 people in the UK.</p> <h3> ֱ̽brain’s role in obesity</h3> <p>Obesity is a major public health concern as it is a significant risk factor for other serious diseases, including cardiovascular disease and type 2 diabetes, yet the genetic reasons why some people are more prone to weight gain are incompletely understood.</p> <p>Previous research has identified several obesity-associated gene variants conferring large effects from childhood, acting through the leptin-melanocortin pathway in the brain, which plays a key role in appetite regulation.</p> <p>However, while both BSN and APBA1 encode proteins found in the brain, they are not currently known to be involved in the leptin-melanocortin pathway. In addition, unlike the obesity genes previously identified, variants in BSN and APBA1 are not associated with childhood obesity.</p> <p>This has led the researchers to believe that they may have uncovered a new biological mechanism for obesity, different to those we already know for previously identified obesity gene variants.</p> <p>Based on published research and laboratory studies they report in this paper, which indicate that BSN and APBA1 play a role in the transmission of signals between brain cells, the researchers suggest that age-related neurodegeneration could be affecting appetite control.</p> <p>Professor John Perry, study author and an MRC Investigator at the ֱ̽ of Cambridge, said: “These findings represent another example of the power of large-scale human population genetic studies to enhance our understanding of the biological basis of disease. ֱ̽genetic variants we identify in BSN confer some of the largest effects on obesity, type 2 diabetes and fatty liver disease observed to date and highlight a new biological mechanism regulating appetite control.”</p> <h3> ֱ̽use of global data</h3> <p> ֱ̽accessibility of large-scale databases such as UK Biobank has enabled researchers to search for rare gene variants that may be responsible for conditions including obesity.</p> <p>For this study, the researchers worked closely with AstraZeneca to replicate their findings in existing cohorts using genetic data from individuals from Pakistan and Mexico. This is important as the researchers can now apply their findings beyond individuals of European ancestry.</p> <p>If the researchers can better understand the neural biology of obesity, it could present more potential drug targets to treat obesity in the future.</p> <p>Dr Slavé Petrovski, VP of the Centre for Genomics Research at AstraZeneca, said: “Rigorous large-scale studies such as this are accelerating the pace at which we uncover new insights into human disease biology. By collaborating across academia and industry, leveraging global datasets for validation, and embedding a genomic approach to medicine more widely, we will continue to improve our understanding of disease – for the benefit of patients.”</p> <h3>Next steps for research</h3> <p>Professor Giles Yeo, study author based at the MRC Metabolic Diseases Unit, added: “We have identified two genes with variants that have the most profound impact on obesity risk at a population level we’ve ever seen, but perhaps more importantly, that the variation in Bassoon is linked to adult-onset and not childhood obesity. Thus these findings give us a new appreciation of the relationship between genetics, neurodevelopment and obesity.”</p> <p><em><strong>Reference</strong><br /> Zhao, T et al. <a href="https://doi.org/10.1038/s41588-024-01694-x">Protein-truncating variants in BSN are associated with severe adult-onset obesity, type 2 diabetes and fatty liver disease.</a> Nat Gen; 4 Apr 2024; DOI: 10.1038/s41588-024-01694-x</em></p> <p><em>Adapted from a press release from the Medical Research Council</em></p> </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Cambridge researchers have identified genetic variants in two genes that have some of the largest impacts on obesity risk discovered to date.</p> </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">We have identified two genes with variants that have the most profound impact on obesity risk at a population level we’ve ever seen</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Giles Yeo</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="https://www.worldobesity.org/resources/image-bank/image-bank-search-results/washing-food-4" target="_blank">World Obesity Federation</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Woman with obesity washing food</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License." src="/sites/www.cam.ac.uk/files/inner-images/cc-by-nc-sa-4-license.png" style="border-width: 0px; width: 88px; height: 31px;" /></a><br /> ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Images, including our videos, are Copyright © ֱ̽ of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our <a href="/">main website</a> under its <a href="/about-this-site/terms-and-conditions">Terms and conditions</a>, and on a <a href="/about-this-site/connect-with-us">range of channels including social media</a> that permit your use and sharing of our content under their respective Terms.</p> </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div><div class="field field-name-field-license-type field-type-taxonomy-term-reference field-label-above"><div class="field-label">Licence type:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/imagecredit/attribution">Attribution</a></div></div></div> Thu, 04 Apr 2024 12:36:17 +0000 Anonymous 245521 at Largest genetic study of brain structure identifies how the brain is organised /research/news/largest-genetic-study-of-brain-structure-identifies-how-the-brain-is-organised <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/brain-512758-1280.jpg?itok=YHBMnNut" alt="Illustration of brain anatomy" title="Illustration of brain anatomy, Credit: holdendrils" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Our brains are very complex organs, with huge variety between individuals in terms of the overall volume of the brain, how it is folded and how thick these folds are. Little is known about how our genetic make-up shapes the development of the brain.</p>&#13; &#13; <p>To answer this question, a team led by researchers at the Autism Research Centre, ֱ̽ of Cambridge, accessed MRI scans from over 32,000 adults from the UK Biobank cohort and over 4,000 children from the US-based ABCD study. From these scans, the researchers measured multiple properties of the outermost layer of the brain called the cortex. These included measures of the area and volume of the cortex as well as how the cortex is folded.</p>&#13; &#13; <p>They then linked these properties, measured both across the entire cortex as well as in 180 individual regions of the cortex, to genetic information across the genome. ֱ̽team identified over 4,000 genetic variants linked to brain structure.</p>&#13; &#13; <p>These findings have allowed researchers to confirm and, in some cases, identify, how different properties of the brain are genetically linked to each other.</p>&#13; &#13; <p>Dr Varun Warrier from the Autism Research Centre, who co-led the study, said: “One question that has interested us for a while is if the same genes that are linked to how big the cortex is – measured as both volume and area – are also linked to how the cortex is folded. By measuring these different properties of the brain and linking them to genetics, we found that different sets of genes contribute to folding and size of the cortex.”</p>&#13; &#13; <p> ֱ̽team also checked whether the same genes that are linked to variation in brain size in the general population overlap with genes linked to clinical conditions where head sizes are much larger or smaller than the general population, known as cephalic conditions.</p>&#13; &#13; <p>Dr Richard Bethlehem, also from the Autism Research Centre and a co-lead of the study, said: “Many of the genes linked with differences in the brain sizes in the general population overlapped with genes implicated in cephalic conditions. However, we still do not know how exactly these genes lead to changes in brain size.”</p>&#13; &#13; <p>Dr Warrier added: “This work shows that how our brain develops is partly genetic. Our findings can be used to understand how changes in the shape and size of the brain can lead to neurological and psychiatric conditions, potentially leading to better treatment and support for those who need it.”</p>&#13; &#13; <p>This study was supported by the Wellcome Trust. It was conducted in association with the NIHR CLAHRC for Cambridgeshire and Peterborough NHS Foundation Trust, and the NIHR Cambridge Biomedical Research Centre.</p>&#13; &#13; <p><em><strong>Reference</strong><br />&#13; Warrier, V et al. <a href="https://www.nature.com/articles/s41588-023-01475-y">Genetic insights into human cortical organisation and development through genome-wide analyses of 2,347 neuroimaging phenotypes.</a> Nat Gen; 17 Aug 2023; DOI: 10.1038/s41588-023-01475-y</em></p>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p> ֱ̽largest ever study of the genetics of the brain – encompassing some 36,000 brain scans – has identified more than 4,000 genetic variants linked to brain structure. ֱ̽results of the study, led by researchers at the ֱ̽ of Cambridge, are published in <em>Nature Genetics</em>.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">Our findings can be used to understand how changes in the shape and size of the brain can lead to neurological and psychiatric conditions, potentially leading to better treatment and support for those who need it</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Varun Warrier</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="https://pixabay.com/illustrations/brain-anatomy-human-science-health-512758/" target="_blank">holdendrils</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Illustration of brain anatomy</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License." src="/sites/www.cam.ac.uk/files/inner-images/cc-by-nc-sa-4-license.png" style="border-width: 0px; width: 88px; height: 31px;" /></a><br />&#13; ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Images, including our videos, are Copyright © ֱ̽ of Cambridge and licensors/contributors as identified.  All rights reserved. We make our image and video content available in a number of ways – as here, on our <a href="/">main website</a> under its <a href="/about-this-site/terms-and-conditions">Terms and conditions</a>, and on a <a href="/about-this-site/connect-with-us">range of channels including social media</a> that permit your use and sharing of our content under their respective Terms.</p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div><div class="field field-name-field-license-type field-type-taxonomy-term-reference field-label-above"><div class="field-label">Licence type:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/imagecredit/public-domain">Public Domain</a></div></div></div> Thu, 17 Aug 2023 15:00:47 +0000 cjb250 241251 at International collaboration identifies new breast cancer susceptibility genes /research/news/international-collaboration-identifies-new-breast-cancer-susceptibility-genes <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/pexels-anna-tarazevich-5482986.jpg?itok=hY5sti6p" alt="Two women holding pink ribbons" title="Two women holding pink ribbons, Credit: Anna Tarazevich" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p> ֱ̽study, published in <em>Nature Genetics</em>, was led by teams at the ֱ̽ of Cambridge and Université Laval, Quebec.</p>&#13; &#13; <p>Current genetic tests for breast cancer only consider a few genes, such as BRCA1, BRCA2, and PALB2. However, these only explain a minority of the genetic risk, suggesting that more genes remain to be identified.</p>&#13; &#13; <p>Researchers looked at genetic changes in all genes in 26,000 women with breast cancer and 217,000 women without breast cancer. These included women from eight countries in Europe and Asia.</p>&#13; &#13; <p>Professor Douglas Easton, Director of the Centre for Cancer Genetic Epidemiology at the ֱ̽ of Cambridge, who co-led the study, said: "To our knowledge, this is the largest study of its kind. It was made possible through the use of data from multiple collaborators in many countries, as well as publicly available data from the UK Biobank.”</p>&#13; &#13; <p> ֱ̽team found evidence for at least four new breast cancer risk genes, with suggestive evidence for many others. ֱ̽team say identification of these new genes will contribute to our understanding of the genetic risk of breast cancer and help improve risk prediction by better identifying those women at higher risk of the disease.</p>&#13; &#13; <p> ֱ̽findings will better inform approaches to breast screening, risk reduction and clinical management. ֱ̽aim is to integrate this information into a comprehensive risk prediction tool currently used worldwide by health professionals.</p>&#13; &#13; <p>"Improving genetic counselling for high-risk women will promote shared decision-making regarding risk reduction strategies, screening and determination of treatment options," said Professor Jacques Simard of Université Laval, co-lead of the study.</p>&#13; &#13; <p>“Although most of the variants identified in these new genes are rare, the risks can be significant for women who carry them. For example, alterations in one of the new genes, MAP3K1, appear to give rise to a particularly high risk of breast cancer.”</p>&#13; &#13; <p>Before this information can be used in a clinical setting, scientists need to validate the results in further datasets.</p>&#13; &#13; <p>"We need additional data to determine more precisely the risks of cancer associated with variants in these genes, to study the characteristics of the tumours, and to understand how these genetic effects combine with other lifestyle factors affecting breast cancer risks," added Professor Easton.</p>&#13; &#13; <p> ֱ̽discovery of these novel genes also provides crucial information on the biological mechanisms underlying cancer development, potentially opening the way to identifying new treatments.</p>&#13; &#13; <p> ֱ̽study was funded by the Government of Canada through Genome Canada and the Canadian Institutes of Health Research, the Ministère de l’Économie et de l'Innovation du Québec through Genome Québec, the Quebec Breast Cancer Foundation, the European Union Horizon programme, the Wellcome Trust and the International Alliance for Cancer Early Detection.</p>&#13; &#13; <p><em><strong>Reference</strong><br />&#13; Wilcox, N et al. <a href="https://www.nature.com/articles/s41588-023-01466-z">Exome sequencing identifies breast cancer susceptibility genes and defines the contribution of coding variants to breast cancer risk.</a> Nat Gen; 17 Aug 2023; DOI :10.1038/s41588-023-01466-z</em></p>&#13; &#13; <p><em>Adapted from a press release by Université Laval</em></p>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>A large-scale international collaboration has identified new genes associated with breast cancer that could eventually be included in tests to identify women at increased risk of the disease.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">To our knowledge, this is the largest study of its kind</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Douglas Easton</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="https://www.pexels.com/photo/2-women-holding-pink-ribbons-5482986/" target="_blank">Anna Tarazevich</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Two women holding pink ribbons</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License." src="/sites/www.cam.ac.uk/files/inner-images/cc-by-nc-sa-4-license.png" style="border-width: 0px; width: 88px; height: 31px;" /></a><br />&#13; ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Images, including our videos, are Copyright © ֱ̽ of Cambridge and licensors/contributors as identified.  All rights reserved. We make our image and video content available in a number of ways – as here, on our <a href="/">main website</a> under its <a href="/about-this-site/terms-and-conditions">Terms and conditions</a>, and on a <a href="/about-this-site/connect-with-us">range of channels including social media</a> that permit your use and sharing of our content under their respective Terms.</p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div><div class="field field-name-field-license-type field-type-taxonomy-term-reference field-label-above"><div class="field-label">Licence type:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/imagecredit/public-domain">Public Domain</a></div></div></div> Thu, 17 Aug 2023 15:00:18 +0000 Anonymous 241351 at