Latest news with #NatureGenetics
Newsweek
14-05-2025
- Health
- Newsweek
OCD Linked to Specific Genes, New Study Finds
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. A new genetic study of more than 50,000 obsessive-compulsive disorder (OCD) cases has linked around 250 genes to the condition, including more than two dozen identified as likely causal, in about 30 regions of the human genome. Why It Matters The study describes obsessive-compulsive disorder as a "chronic psychiatric disorder that affects 1 to 3 percent of the population." Symptoms vary widely in form and severity, with some people experiencing debilitating compulsions that disrupt daily life, while others have milder, more manageable symptoms. Some people diagnosed with OCD experience chronic anxiety, repetitive thoughts, chronic fears and paranoia, among symptoms. The study claims its findings "substantially advances the field of OCD genetics" due to the identification of new OCD genetic risk loci and multiple credible candidate causal genes. What To Know Nearly 200 researchers from universities in Europe, North America, and Australia conducted and published the largest study on OCD in Nature Genetics on May 13. The study marks the most comprehensive understanding of OCD yet, comparing DNA from 53,660 people with OCD to over 2 million people without it. It identified 30 specific loci where DNA variants are associated with higher susceptibility to OCD, most active in three brain areas: the hippocampus, striatum, and cerebral cortex. "By looking closely at the identified DNA regions, we pinpointed 249 potential genes involved in OCD and then narrowed this down to 25 particularly strong 'candidate' genes," which are also known as causal genes, "because they can be involved in the process of causing OCD," Marco Galimberti, a lead researcher on the study and an associate research scientist at Yale School of Medicine's Gelernter Lab, told Newsweek. Stock photo of an illustrative model of a brain on the table next to a young EEG test subject. Stock photo of an illustrative model of a brain on the table next to a young EEG test subject. Jacob Schr'ter/picture-alliance/dpa/AP Image "Some of these causal genes are WDR6, DALRD3 and CTNND1 and multiple genes in the major histocompatibility complex (MHC) region," he added. The 25 likely causal genes were identified through at least two independent gene-based tests and passed colocalization and other statistical tests, indicating they are likely affected by the same genetic variants that increase the risk for OCD. The study also found that there is a genetic overlap with OCD and several other psychiatric conditions and disorders, finding, "In particular, OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome and was negatively associated with inflammatory bowel diseases, educational attainment and body mass index." Galimberti told Newsweek he found this finding "particularly interesting," however, noting that "the relationship between OCD and Tourette syndrome may not be surprising." What People Are Saying Professor Eske Derks, senior group leader of the Translational Neurogenomics Laboratory at QIMR Berghofer, said: "This is the first study where we found actual genes that play a role in OCD, which is really found a really large number of genes which are shared with anxiety disorders, depression and also with anorexia nervosa. There's a lot of overlap in the genes that cause these different mental health conditions." Carol Mathews, chair of the University of Florida's College of Medicine's Department of Psychiatry, said about the study: "When we started early in my career, we were looking for genes that cause OCD. We thought back then that it would be one or two. Over time, we've come to realize that OCD is not a disease of a single gene or specific brain region, but rather it's a disease of circuits and hundreds of genes, which together contribute to the development of the disorder." Manuel Mattheisen, a Dalhousie University research chair and lead senior author on the paper, said in a press release: "These findings emphasize the need for a comprehensive exploration of the contribution of both common and rare genetic factors, as well as their interplay to OCD risk. Future studies will require ancestrally diverse samples to facilitate the discovery of additional OCD risk variants, understanding that these results may be useful for drug repurposing and yield new, more effective treatments." Mataix-Cols, professor at the Karolinska Institute in Stockholm, one of the international collaborators, said in the press release: "After decades of fumbling in the dark, we have finally cracked the piñata of OCD genetics. This study required unprecedented international collaboration, and I am proud of Sweden's contribution to this effort." What Happens Next Galimberti told Newsweek that the researchers "have not conducted analyses on epigenetics in this work. However, it is likely that epigenetics may play a role on OCD as well as on other psychiatric disorders and behavioral traits." Studies like this are often used to guide drug development, improve treatment options, and increase research and public awareness.
ABC News
13-05-2025
- Health
- ABC News
Study finds 25 genes believed to cause obsessive-compulsive disorder
Researchers have identified 25 genes they believe cause obsessive-compulsive disorder (OCD). In the largest global study of the disorder, they compared genetic data from more than 50,000 people worldwide who have the debilitating condition, with the DNA of about two million people who do not have OCD. Medical researcher Eske Derks, one of the study's senior authors, said it was the first time "actual genes that play a role in OCD" had been found. The senior group leader of QIMR Berghofer's translational neuro-genomics laboratory, said the study had identified about 250 genes linked to OCD, including 25 they believe to be causal. "We found a really large number of genes which are shared with anxiety disorders, depression and also with anorexia nervosa," Professor Derks said. "There's a lot of overlap in the genes that cause these different mental health conditions." She said twin studies had already revealed OCD was a heritable condition, but environmental factors, such as stressful life events also played a role. Professor Derks said she hoped the latest research, published in Nature Genetics, would help reduce the stigma surrounding the disorder. OCD is characterised by obsessive thoughts and behaviours, such as compulsive cleaning, checking things and hoarding. But it can take many forms including people worrying about harming others, having doubts about relationships, intrusive sexual thoughts, or persistent concern about their responsibilities in life. OCD is one of the World Health Organisation's ten leading causes of disability. Professor Derks said the researchers hoped to use the genetic information to help find more targeted drugs for severe cases of OCD, which affects an estimated 500,000 Australians. "The next steps for our research team is to use these genetic discoveries to identify existing drugs, currently being used to treat other conditions, that may be effective for OCD patients, paving the way for more innovative treatment options," she said. But she said that would require more funding. "It's understudied." Brisbane-based clinical psychologist and OCD specialist Emily O'Leary said gold standard treatment for someone with moderate to severe OCD was a combination of psychological therapy and medication. "Early intervention is usually linked with better outcomes," she said. "The longer someone lives with OCD, the harder it can be to treat. "On average, it takes about 10 years from the outset of diagnosis to receive psychological help. By the time they reach us, many are unwell." Dr O'Leary said she hoped emerging genetic research would eventually lead to a blood test for OCD — helping identify those at risk and opening the door to early intervention. Respected University of Queensland psychiatric researcher Professor John McGrath, who was not involved in the Nature Genetics study, said the research may lay the groundwork for the search for better OCD treatments.
The Hindu
13-05-2025
- Health
- The Hindu
East Asians began evolving to drink milk before they reared cattle
Female mammals produce milk to nourish their young. Much of the nourishment comes from lactose, the major sugar in milk. The lactose is broken down in the infant's small intestine into the more simpler sugars, glucose, and galactose, which are readily absorbed by the small intestine. The break-down, or digestion, of lactose is mediated by an enzyme called lactase. After weaning, a baby rapidly loses the ability to produce lactase. When adults consume milk, cheese, ice cream or other dairy products, many of them experience unpleasant effects like bloating, flatulence, and diarrhoea. This is because the undigested lactose passes into the large intestine, where it is utilised by the bacteria residing there. This produces hydrogen, carbon dioxide, and methane, and the unabsorbed sugars increase water flow into the bowels to produce diarrhoea. These are the hallmarks of lactose intolerance. Yet millions of people around the world regularly indulge in milkshakes, cheese pizzas, and ice cream sundaes even as adults. This is because they carry genetic mutations that allow them to continue producing lactase even as adults. This trait is called lactase persistence. A textbook example The mutations that confer lactase persistence emerged independently in different populations. Their emergence in North European and African populations in particular appears to have coincided with the domestication of cattle, buffaloes, goats, sheep, and other livestock, which began about 11,000 years ago. The cultural shift from hunting/gathering to pastoralism gave continued access to meat, milk, and hides from herds of domesticated animals. The coincidental emergence of lactase persistence mutations with livestock domestication was taken by many scientists at the time to be a 'textbook example' of convergent evolution. That is, the independent evolution of similar traits in distantly related populations. Experts believed it was driven, in the words of a 2007 paper in Nature Genetics, by the 'strong selective pressure resulting from shared cultural traits — animal domestication and adult milk consumption'. A wrinkle in the textbook Scientists may need to reevaluate this neat summation in the light of new findings reported by a team of researchers from Fudan University in Shanghai, China; the Max Planck Institute for Evolutionary Anthropology, in Leipzig, Germany; and the Université de Lyon in France. Their findings were published in the Proceedings of the National Academy of Sciences. The researchers found a distinct evolutionary pathway for lactase persistence in East Asian populations, which includes the Chinese, the Japanese, and the Vietnamese. Unlike the gene-and-culture coevolution well-documented in African and European groups, the East Asian lactase persistence gene had come from the Neanderthals, an archaic group of humans that went extinct about 30,000 years ago. When the researchers conducted population genetic analyses of the part of the genome containing the lactase gene, they found evidence of pre-agricultural selection pressures beginning more than 30,000 years ago. That is, the East Asian genomes began evolving towards lactase persistence several millennia before these populations began to domesticate livestock. This early evolution likely targeted advantages related to the immune system rather than lactose digestion directly. The researchers found the East Asian (Neanderthal-derived) lactase gene showed the same expression pattern as the mutant responsible for lactase persistence in Europeans. This suggested it also conferred lactate persistence. Neanderthals in our genome About 7 million years ago, the evolutionary line leading to the contemporary Homo sapiens diverged from the one leading to our closest living cousins, the chimpanzees and bonobos. About 800,000 years ago, our line split once more: one population broke away and migrated to Eurasia, adapting to cold climes and eventually becoming the Neanderthals. The other stayed put in Africa and, by about 200,000 years ago, evolved into modern humans. Modern humans migrated out of Africa into Eurasia 120,000 to 80,000 years ago, and came into contact with their Neanderthal cousins there. DNA evidence from skeletal remains dating to after the contact showed the two occasionally interbred as well. As a result, today, about 1-4% of the genome of individuals with Eurasian ancestry — i.e. Europeans, East Asians, Indians, Native Americans, and Oceanians — represents Neanderthal-derived DNA sequences. The lactase gene of East Asians was one such segment. On the other hand, those of African descent have close to 0% Neanderthal-derived sequences. About 30,000 years ago the Neanderthals went extinct for reasons that are still not clear. Bones to pick Experts can distinguish Neanderthal skeletal remains from those of modern humans by the shape of the skull, inner ear bones, and pelvis width. Neanderthal bones have yielded DNA, which scientists have sequenced and compared with that of H. sapiens. Two random humans share about 99.9% of their DNA sequence whereas humans and Neanderthals shared only about 99.7%. Thus, there are about 9.6 million points of difference between Neanderthal and human DNA sequences, in terms of the bases the DNA is made of. Based on these differences, if a DNA sequence is sufficiently long, one can tell whether it is from humans or Neanderthals. The Allen Ancient DNA Resource (AADR) is a curated database of more than 10,000 genome sequences from the skeletal remains of ancient individuals who lived up to 20,000 years ago. The researchers who put this resource together have also identified, on every genome, more than a million sites where the DNA has been known to exhibit a different ordering of bases than 'normal'. About 67% of the ancient DNA sequences in AADR are from remains recovered in Europe and Russia, some 8% each are from East Asia and the Near East, about 7% are from the Americas, about 5% are from South and Central Asia, about 3% from Africa, and about 2% from Oceania. A story upended The researchers behind the new study searched AADR and found one modern human who lived around 14,000 years ago in the Amur area of China. This individual carried the Neanderthal-derived lactase gene. The gene occurred in roughly 10% of those humans who lived 8,000 to 3,000 years ago, and in about 20% of those who lived about 3,000 to 1,000 years ago. Its current frequency among East Asians is 28.9%. Thus, the AADR data also supported the inference made from the population genetic analyses: that the lactase gene had already experienced selection and had reached a (relatively) high frequency among East Asians long before they began to domesticate animals. Thus either the selection in East Asians, unlike that in Africans and North Europeans, was for reasons other than lactase persistence, or in all three geographies the selection was similarly not for lactase persistence. Either way in the light of these findings the classic story of gene–culture coevolution has become more complicated and hence, as the researchers note, more interesting. D.P. Kasbekar is a retired scientist.
The Hindu
29-04-2025
- Science
- The Hindu
Scientists unlock genetic key to higher peanut yield
A team of 19 researchers from Australia and China have unlocked the genetic key to developing higher-yielding varieties of peanut or groundnut, a major food and oilseed crop in India. Their pan-genome analysis, revealing the structural variation associated with seed size and weight traits in peanut (Arachis hypogaea L.), was published in the latest edition of Nature Genetics, a peer-reviewed scientific journal. The researchers from Western Australia's Murdoch University, Henan Agricultural University, Shanghai Jiao Tong University, and the Shandong Academy of Agricultural Sciences assembled a pan-genome of peanut expected to serve as a fundamental resource for the genetic enhancement of legume crops. A pan-genome represents the entire range of genes within a population or species, encompassing both unique and shared genetic material. The study marks three Chinese lead authors – Kunkun Zhao, Hongzhang Xue, and Guowei Li – as equal contributors. Among its other authors are Annapurna Chitikineni and Rajeev K. Varshney from Murdoch University. The researchers studied the genome-wide diversity of 269 peanut accessions, including 61 wild species, landraces and improved species. They found significant genomic variations and highlighted two of the most critical traits that affect peanut yield: seed size and weight. Accession refers to a distinct sample or group of plant material, typically representing a single species or cultivar, collected from a specific location at a particular time. A landrace is a local cultivar improved by traditional agricultural methods. Tracing the evolution of domesticated peanut varieties from their wild relatives, the researchers discovered that the gene likely responsible for regulating cell division and yield size was absent in all the wild species analysed. Gene deletion The researchers also found that deleting a gene that negatively regulates the seed size makes the seeds bigger. 'Our understanding of the molecular mechanisms and evolutionary factors that influence peanut pod size and weight used to be limited. This study offers the most comprehensive genomic variation resource of the globally important peanut and will be an invaluable tool for crop breeding efforts,' Prof. Varshney said. The lack of clarity about genomic rearrangements like structural variations underlying seed size and weight – critical traits for domestication and breeding – led to the study. The researchers presented a comprehensive pan-genome analysis, utilising eight high-quality genomes (two diploid wild, two tetraploid wild, and four tetraploid cultivated peanuts) and resequencing data of 269 accessions with diverse seed sizes. 'We identified 1,335 domestication-related [structural variations] and 190 structural variations associated with seed size or weight. Our study revealed that structural variations could influence gene expression, functional dynamics, and uneven domestication between two sub-genomes, ultimately affecting seed size and weight,' the study said. The most notable part of the study was the deletion of the AhARF2-2 gene, which results in the loss of two other genes, reducing the inhibitory effect on a third and promoting seed expansion. Beyond peanuts The researchers said structural variations, along with single-nucleotide polymorphism and epigenetic differences, are emerging as important variation features contributing to the genetic and phenotypic diversity observed in and between species. 'Understanding the impact of structural variations on plant phenotypic variation is crucial for breeders aiming to develop superior cultivars,' they said. The comprehensive peanut pan-genomes they developed resulted in an extensive resource of genomic variations that contribute to key agronomic traits in peanuts. The study said these 'will facilitate advancements in crop science and peanut breeding, thereby potentially improving global food security'. 'What makes this research especially exciting is that it offers new information that can be applied to numerous crops of economic importance, such as cotton and rapeseed,' Peter Davies, the Director of Murdoch University's Food Futures Institute, said.
The Hindu
26-04-2025
- Health
- The Hindu
No phenotype data details in GenomeIndia's proposal call
On January 9, 2025, the Department of Biotechnology (DBT) called for proposals on 'Translational research using genomeIndia data' from scientists based in India. On February 20, eight days before the February 28 deadline for submitting proposals, DBT extended the deadline till March 31, 2025. The 10,000 human genome project had collected blood samples and associated phenotype data from over 20,000 individuals representing 83 population groups — 30 tribal and 53 non-tribal populations — spread across India. Of the 20,000 individuals, preliminary findings based on the genetic information of 9,772 individuals were published in the journal Nature Genetics as a Comment on April 8. The Comment article clearly listed the phenotype data collected from over 20,000 people, including height, weight, hip circumference, waist circumference and blood pressure. From blood samples collected, complete blood counts as well as biochemistry data such as glucose measurements, lipid profiles, and liver and kidney function tests were measured and are available along with genome data of 9,772 individuals. Surprisingly, neither the first proposal call nor the addendum extending the deadline for submitting the proposals listed what phenotype data were available to researchers. Even the GenomeIndia website does not have that information. The first time that information became public was when the Comment article was published on April 8. But the deadline for submitting the proposals was March 31. 'The anthropometric and blood biochemistry data were only collected to ensure that the samples covered under the GenomeIndia project were from healthy individuals,' says a DBT spokesperson in an email to The Hindu. 'The GenomeIndia project has not published a data dictionary nor released detailed information on the available phenotype metadata of the genotyped samples in the project. A Commentary in the Nature Genetics journal has been the first and only public communication about the details of phenotype metadata in the project, till date. Even before the publication of this article, DBT has completed a proposal inviting researchers for utilising the GenomeIndia data,' says Dr. Padmanaban V, Assistant Professor in the Department of Biochemistry at CMC Vellore. Incidentally, the addendum published on February 20 extending the deadline to March 31 noted that DBT had 'received many queries regarding the type of data that will be released'. Despite saying 'relevant phenotype data (as per request)' will be provided under Controlled (Managed) Access, what phenotype data that were available was not provided. 'Despite admitting that there have been many queries related to the data, there still wasn't any information on the list of available phenotypes that researchers can request even in this document,' says Dr. Padmanaban. Also, the Comment piece published in the journal, which is the only place the phenotype data is collected and available, was mentioned, is behind a paywall, thus restricting some researchers from reading it. The spokesperson points out that the One Nation One Subscription scheme will provide access to research articles and journal publications to students, faculty and researchers. However, the One Nation One Subscription scheme currently provides free access to journal papers to researchers and students only from public institutions. While researchers from 20 institutions involved in the GenomeIndia project would be aware of the phenotype data available, others would be unaware of it. 'Researchers who were not part of the GenomeIndia project team did not have information on the available phenotype metadata,' says Dr. Padmanaban. 'Not only GenomeIndia data but any biological data available at IBDC can be accessed by researchers as per provisions in Biotech PRIDE Guidelines and FeED Protocols, which are in harmony with practices followed by international databases,' the spokesperson says.
