Latest news with #PNASNexus
IOL News
29-07-2025
- Health
- IOL News
Could gene editing help prevent Down syndrome? Insights into CRISPR's potential
Many families and advocates express concerns about retaining the inherent beauty and value of diversity, fearing that efforts to "delete" a condition might overshadow the vibrant personalities and lives of those who embody it. Image: Cliff Booth/pexels Imagine a world where the very building blocks of our DNA could be gently edited, removing what brings suffering, without erasing what makes us uniquely human. That's exactly the kind of future scientists are now daring to explore, thanks to a new breakthrough in gene editing that has the medical community buzzing with hope and raising some tough questions. Editing out the extra chromosome Recently, researchers at Mie University in Japan accomplished something that, until now, was only the stuff of science fiction: they used a tool called CRISPR-Cas9 to remove the extra copy of chromosome 21 from cells affected by Down syndrome. Their findings, published in the journal PNAS Nexus, could mark the start of a new era in how we think about treating (and maybe even preventing) this common genetic condition. 'We designed our CRISPR system to target the extra chromosome without affecting the normal pair,' explained Dr Ryotaro Hashizume, the project's lead scientist. 'Our goal was to remove the surplus material and see whether the cell's gene expression returned to typical levels.' What is Down syndrome? We've all heard of Down syndrome, but what actually causes it? In simple terms, it happens when a person is born with three copies of chromosome 21 instead of the usual two. This extra genetic material disrupts the body's usual blueprint, leading to a variety of challenges, from intellectual disabilities and heart defects to higher risks of Alzheimer's disease and other health conditions. Down syndrome, commonly associated with an intellectual disability, arises when a person is born with three copies of chromosome 21 rather than the usual two, leading to various developmental challenges Image: Google DeepMind/pexels Three main types of Down syndrome exist: Trisomy 21 (the most common): Every cell in the body has an extra chromosome 21. Mosaic Down syndrome: Only some cells have the extra copy, leading to milder symptoms. Translocation Down syndrome: The extra chromosome attaches to a different chromosome, which affects how symptoms appear. Down syndrome is more common than many realise, affecting about 1 in 700 babies born in the world, according to the CDC. While the chance increases with maternal age, most babies with Down syndrome are actually born to younger mothers, simply because they have more children overall. How does CRISPR work its magic? CRISPR-Cas9 is often called 'genetic scissors'. It can cut DNA at precise spots, allowing scientists to remove, repair, or add genetic material. In the Mie University study, researchers programmed CRISPR to specifically target and cut the extra chromosome 21 in both stem cells and mature skin cells from people with Down syndrome. Following the removal of the extra chromosome, the cells behaved more like typical cells: Their growth improved. They produced fewer harmful byproducts (linked to cell ageing). Genes related to brain development became more active. This aligns with decades of research published in the National Institutes of Health showing that the extra chromosome 21 interferes with normal development. What could this mean for people with Down syndrome? If this technology ever leaves the lab, it could be revolutionary. Imagine therapies where a person's own cells are edited and returned to their body, potentially improving heart health, boosting brain function, and reducing the risk of early-onset Alzheimer's. But (and it's a big but), we're not there yet. According to Hashizume, this technique is not yet ready for use in hospitals or in routine medical practice. But it sets a new benchmark for what CRISPR can do, not just editing single genes, but removing entire chromosomes. Any conversation about 'deleting' a genetic condition sparks strong feelings. What does it mean to change something so fundamental? Some families and advocates worry about losing the beauty and value in diversity, including the lives and personalities of people with Down syndrome. And while prenatal screening has made Down syndrome rare in some countries, the global conversation is just beginning: Should we use science to eliminate a condition, or focus on making life better for people who live with it? As we watch this story unfold, one thing is certain: the future of health, wellness, and genetics will be shaped not just by labs and scientists, but by all of us, families, advocates, and a world still learning to celebrate differences.
International Business Times
03-07-2025
- Science
- International Business Times
Antarctica's Disappearing Ice Is a Red Alert for Wildlife — and Us; Here's Why!
A new study, published in PNAS Nexus, an extension of the US journal Proceedings of the National Academy of Sciences for high-impact, emerging research, revealed that the Antarctic summer sea ice is retreating at record rates, causing a cascade of environmental and social repercussions that could significantly change the world's climate and ecosystems, according to Australian experts. The Australian Antarctic Program Partnership (AAPP) at the University of Tasmania led the study, which found that record lows in sea-ice extent are heating oceans, exposing coastlines, and upsetting fragile ecosystems while also increasing public fear of climate change. According to an AAPP release, the study, which synthesizes effects across ocean systems, ecosystems, and human societies, shows that severe sea-ice lows, such as those seen in recent years, cause three interrelated crises. Edward Doddridge, the lead author of the study from the AAPP, said that the loss of sea ice increases the risk of sea-level rise because it weakens the ice shelf, increases wave damage, and causes more iceberg calving—there are six more icebergs per 100,000 km² lost. The study noted that a persistent, self-reinforcing cycle of ocean warming is caused by the disappearance of sea ice, which increases the absorption of solar heat by dark open waters. Algal blooms in these areas further trap warmth. The study also revealed that public interest peaked during the record sea-ice lows in 2023, and that increased media coverage of Antarctic ice loss is linked to growing climate anxiety and mental health concerns.
Sydney Morning Herald
01-07-2025
- Science
- Sydney Morning Herald
Trump cuts satellite data on Antarctic sea ice just as it's needed most
The US decision is part of what has been widely described as an assault on climate science by the Trump administration. It also affects other work by NASA and the National Oceanic and Atmospheric Association, including hurricane forecasting, as reported by The Guardian US. This masthead sent questions to the US embassy in Australia and the Pentagon, but did not receive a response by deadline. One important dataset under threat is the Sea Ice Index, which has continuous readings back to the late 1970s. It shows that until about 2015, sea ice was around average, or even a bit above average, but since 2016 it has been consistently low. Doddridge said the satellites were past their mission life but remained operational, suggesting the data would still exist but not be shared for scientific work, forcing scientists to use sources with less reliability and continuity such as Japanese or Chinese satellites. 'We won't lose complete access to sea ice data,' Doddridge said. 'What we will lose is a long-term record of well-calibrated, interoperable satellite sensors. What that means is that we won't be able to compare future extremes with past extremes anywhere near as accurately.' The impacts of extremely low sea ice in Antarctica The PNAS Nexus paper canvasses a wide range of impacts from extremely low sea ice, from ecological harm to feedback loops for global warming. Emperor penguins needed landfast sea ice for breeding platforms, Doddridge said, while Adelie penguins relied on sea ice to stay dry while they underwent a 'catastrophic moult', in which they replace all their feathers over a few weeks and temporarily lose their waterproofing. Crabeater seals give birth to their pups on large ice floes and need to stay with them for the two to three weeks between birth and weaning, but are vulnerable to predators such as leopard seals if the ice floes become smaller or harder to find. The paper also raises the spectre that low sea ice could affect the population of Antarctic krill, small crustaceans that are a main food source for a number of whale species, and which need sea ice in the larval stage. Loading Perhaps the biggest impact of low sea ice is the feedback effect it could have on the destruction of the ice shelf – the part of the ice sheet of compacted snow that sits on the ocean rather than over rock – through iceberg formation or melting, and the corresponding effect on sea level rises. Dr Sue Cook, a glaciologist and co-author on the PNAS Nexus paper, said sea ice suppressed ocean swells and waves close to the ice shelf. If the ice shelf was directly exposed to swell, it would start to bend and crack and might disintegrate into icebergs that then disperse out into the open ocean, Cook said. 'In the 15-year record that we looked at, the years with the least summer sea ice produced more than twice as many icebergs as the years with the most summer sea ice,' Cook said. 'This link between iceberg production and sea ice presence isn't something that we include in any of our ice sheet models at the moment, and that means that we might be underpredicting how quickly the Antarctic margin will retreat as sea ice dwindles around the continent.' She added that most models were based on 15 to 20 years of data, which included long periods of good sea ice coverage. 'If we shift to this state where summer sea ice is very low, but we continue using models based on the previous period, then we will definitely underestimate how quickly Antarctica will contribute to sea level rise,' she said. Dr Will Hobbs, a sea ice scientist with AAPP and co-author of the paper, said one of the most important roles of sea ice was the albedo effect, in which it essentially acts as a sunshade in summer. This works because snow-covered ice reflects about 90 per cent of the sunlight back into space, whereas the darker water of the open ocean absorbs 90 per cent of the sunlight, and warms accordingly. Hobbs said that historically in the Southern Ocean, the system always resets in the midwinter, but the researchers found that in a year of extremely low ice, such as 2016, it would affect the next summer and take about three years to fully recover. Hobbs said statistical analysis using reconstructions of the last century suggested there was a 0.1 per cent chance that the low sea ice trend was part of natural variability.
The Age
01-07-2025
- Science
- The Age
Trump cuts satellite data on Antarctic sea ice just as it's needed most
The US decision is part of what has been widely described as an assault on climate science by the Trump administration. It also affects other work by NASA and the National Oceanic and Atmospheric Association, including hurricane forecasting, as reported by The Guardian US. This masthead sent questions to the US embassy in Australia and the Pentagon, but did not receive a response by deadline. One important dataset under threat is the Sea Ice Index, which has continuous readings back to the late 1970s. It shows that until about 2015, sea ice was around average, or even a bit above average, but since 2016 it has been consistently low. Doddridge said the satellites were past their mission life but remained operational, suggesting the data would still exist but not be shared for scientific work, forcing scientists to use sources with less reliability and continuity such as Japanese or Chinese satellites. 'We won't lose complete access to sea ice data,' Doddridge said. 'What we will lose is a long-term record of well-calibrated, interoperable satellite sensors. What that means is that we won't be able to compare future extremes with past extremes anywhere near as accurately.' The impacts of extremely low sea ice in Antarctica The PNAS Nexus paper canvasses a wide range of impacts from extremely low sea ice, from ecological harm to feedback loops for global warming. Emperor penguins needed landfast sea ice for breeding platforms, Doddridge said, while Adelie penguins relied on sea ice to stay dry while they underwent a 'catastrophic moult', in which they replace all their feathers over a few weeks and temporarily lose their waterproofing. Crabeater seals give birth to their pups on large ice floes and need to stay with them for the two to three weeks between birth and weaning, but are vulnerable to predators such as leopard seals if the ice floes become smaller or harder to find. The paper also raises the spectre that low sea ice could affect the population of Antarctic krill, small crustaceans that are a main food source for a number of whale species, and which need sea ice in the larval stage. Loading Perhaps the biggest impact of low sea ice is the feedback effect it could have on the destruction of the ice shelf – the part of the ice sheet of compacted snow that sits on the ocean rather than over rock – through iceberg formation or melting, and the corresponding effect on sea level rises. Dr Sue Cook, a glaciologist and co-author on the PNAS Nexus paper, said sea ice suppressed ocean swells and waves close to the ice shelf. If the ice shelf was directly exposed to swell, it would start to bend and crack and might disintegrate into icebergs that then disperse out into the open ocean, Cook said. 'In the 15-year record that we looked at, the years with the least summer sea ice produced more than twice as many icebergs as the years with the most summer sea ice,' Cook said. 'This link between iceberg production and sea ice presence isn't something that we include in any of our ice sheet models at the moment, and that means that we might be underpredicting how quickly the Antarctic margin will retreat as sea ice dwindles around the continent.' She added that most models were based on 15 to 20 years of data, which included long periods of good sea ice coverage. 'If we shift to this state where summer sea ice is very low, but we continue using models based on the previous period, then we will definitely underestimate how quickly Antarctica will contribute to sea level rise,' she said. Dr Will Hobbs, a sea ice scientist with AAPP and co-author of the paper, said one of the most important roles of sea ice was the albedo effect, in which it essentially acts as a sunshade in summer. This works because snow-covered ice reflects about 90 per cent of the sunlight back into space, whereas the darker water of the open ocean absorbs 90 per cent of the sunlight, and warms accordingly. Hobbs said that historically in the Southern Ocean, the system always resets in the midwinter, but the researchers found that in a year of extremely low ice, such as 2016, it would affect the next summer and take about three years to fully recover. Hobbs said statistical analysis using reconstructions of the last century suggested there was a 0.1 per cent chance that the low sea ice trend was part of natural variability.
New York Post
19-06-2025
- Health
- New York Post
Could Down syndrome be eliminated? Scientists say cutting-edge gene editing tool could cut out extra chromosome
Cutting-edge gene editing technology could eradicate Down syndrome, according to Japanese scientists. Down syndrome, which causes a range of developmental differences and affects 1 in 700 newborns in the United States, is caused by the presence of an extra copy of chromosome 21. The extra chromosome, also known as trisomy 21, causes cellular overactivity, compromises a range of processes within the body, and can manifest in distinctive physical traits, learning difficulties, and health concerns. Advertisement Now new research out of Mie University in Japan suggests that by using the DNA-modifying tech CRISPR, it is possible to remove the surplus chromosome in affected cells and bring cellular behavior closer to typical function. 3 Down syndrome, which causes a range of developmental differences and affects 1 in 700 newborns in the United States, is caused by the presence of an extra copy of chromosome 21. Mongkolchon – CRISPR-Cas9 is a gene-editing system that utilizes an enzyme to identify specific DNA sequences. Once the enzyme locates a matching site, it snips through the DNA strands. Ryotaro Hashizume and his colleagues designed CRISPR guides to target only the trisomy 21 chromosome, a process called allele-specific editing, which directs the cutting enzyme to the desired spot. Advertisement When they used it on lab-grown cells, removing the extra copy of the gene normalized the way the genes expressed themselves in the body — suggesting that the genetic burden had been removed. They also found that after the extra chromosome was removed, genes tied to nervous system development were more active and those related to metabolism were less active. This backs up previous research that found extra copies of chromosome 21 disrupt brain development during early fetal growth. Researchers also tested their CRISPR guides on skin fibroblasts, which are mature, non-stem cells taken from people with Down syndrome. Advertisement In these fully developed cells, the editing method successfully removed the extra chromosome in a number of cases. 3 Hashizume and his team designed CRISPR guides to target only the trisomy 21 chromosome, a process called allele-specific editing, which directs the cutting enzyme to the desired spot. Gorodenkoff – After removal, these corrected cells grew faster and had a shorter doubling time than untreated cells, suggesting that removing the extra chromosome may help with the biological strain that slows down cell growth. Advertisement But the CRISPR can affect healthy chromosomes, too, and researchers are refining their program so that it only attaches to the extra copy of chromosome 21. This work proves that, rather than making small fixes, CRISPR can eliminate an entire chromosome. The scientists published their findings in PNAS Nexus. Hashizume and his team are hopeful that their work may be used to design regenerative therapies and treatments that address genetic surplus at its source. 3 Researchers also tested their CRISPR guides on skin fibroblasts, mature, non-stem cells taken from people with Down syndrome. Yakobchuk Olena – Researchers will continue to analyze the risks of DNA changes and monitor how modified cells function over time and their viability in real-world settings. A recent case study explored a medical mystery related to Down syndrome; the brain of an American woman with Down syndrome showed all the classic signs of Alzheimer's disease, yet she remained symptom-free throughout her lifetime. Advertisement People with Down syndrome face a much higher risk of developing Alzheimer's-related dementia as they age — an estimated three to five times higher than the general population. Scientists are still working to pinpoint the exact cause, but it's believed that the extra copy of chromosome 21 drives the overproduction of amyloid precursor protein. This excess production leads to the buildup of amyloid beta plaques in the brain, a hallmark of Alzheimer's disease.
