Scientists take next big step in understanding genetics of schizophrenia

Genetically speaking, we are individuals different from each other because of slight variations in our DNA sequences — so-called genetic variants — some of which have dramatic effects we can see and comprehend, from the color of our eyes to our risk for developing schizophrenia — a debilitating psychiatric condition affecting many millions worldwide. For several years, scientists have studied the entire genomes of thousands of people — called genome-wide association studies, or GWAS — to find approximately 5,000 genetic variants associated with schizophrenia.

Now, UNC School of Medicine scientists and colleagues are figuring out which of these variants have a causal effect in the development of the schizophrenia. They are finding that some of genetic variants regulate or alter the expression of genes involved in the condition.

Published in the journal Cell Genomics, this research marks a big step forward in our understanding of the genetic basis of schizophrenia.

“Our findings not only provide insights into the intricate regulatory landscape of genes, but also propose a groundbreaking approach to decoding the cumulative effect of genetic variants on gene regulation in individuals with schizophrenia,” said senior author Hyejung Won, Ph.D., associate professor of genetics at the UNC School of Medicine. “This comprehension could potentially pave a path for more precise interventions and therapies in the future. Right now, therapeutic options are limited, and some people do not respond to drugs available.”

For this study, Won and first authors Jessica McAfee and Sool Lee, both UNC-Chapel Hill graduate students, led a team of researchers from UCLA, Harvard, the University of Michigan, and Human Technopole in Italy to explore the genetic variants already linked to the risk of schizophrenia through GWAS research. Their goal was to figure out a way to tease apart meaningless variants from those with potential for biological activity important for developing schizophrenia. This isn’t easy for a few reasons, one of which is that genetic variants are often inherited together from parents. So, right next to each other could be two genetic variants associated with the condition — one might be important for gene expression that plays a major role in the condition, but the other variant might not have any role in the condition.

To tackle this problem, the researchers used a special technique called a massively parallel reporter assay (MPRA) — essentially a genetic sequencing technique that can parse which variants trigger gene expression and which ones don’t. To use this method, the researchers introduced the 5,000 variants into human brain cells in a dish, cells that are essential for early brain development. These variants may or may not cause the expression of their downstream gene and genetic barcode. The barcode, a 20bp DNA sequence, is unique to each variant. This is what the group uses to distinguish the variant sequences. The MPRA revealed 439 genetic variations with actual biological effects, meaning they can alter expression of gene.

“Traditionally, scientists have used other epigenetic data, such as transcription factor binding and biochemically defined enhancers, to identify variants with biological effects,” Won said. “However, these conventional methods failed to predict a large portion of variants we identified to have biological effects. Our work points to a wealth of unexplored variants with biological effects.”

To understand how these variants work together to influence gene activity, Won and colleagues developed a new model that combines data from MPRA with chromatin architecture of brain cells — that is, the genetic information important for how brain cell DNA is organized. By doing this, the researchers could connect these 439 variants to how genes are turned on or off.

“Schizophrenia is a complex condition that is highly heritable,” Won said. “To find these 439 potentially causal variants is a big step, but we still have a lot of work ahead to figure out the complicated genetic architecture that leads an individual to develop this condition. With that information in hand, we could begin to understand the biological mechanism underlying this complex disorder, which may eventually lead to targeted therapies.”

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Judge to decide on ending critically ill baby girl’s life support

Medics say they can do no more for six-month-old Indi but her parents are opposing the decision.

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Women receiving inflated risks from genetic testing could undergo unnecessary breast surgery

Women could be opting to have unnecessary surgery to avoid breast cancer, after being told they are at high risk from genetic test results which do not take family history into account.

The authors of new research led by the University of Exeter have warned that women who discover, outside of a clinical setting, that they carry a disease-causing variant in one of the BRCA genes (BRCA1 or BRCA2) may be told their risk of breast cancer is 60-80 per cent. In fact, the risk could be less than 20 per cent if they do not have a close relative with the condition.

The warning has emerged in a paper published today in the Lancet journal eClinical Medicine. Until recently, women who received BRCA results did so because they attended clinic due to symptoms, or a family history of disease. The likelihood of certain BRCA variants causing breast cancer has been calculated based on this already high-risk group. However, many people now pay for home DNA testing kits, or are given results as part of taking part in genetic research, without ever having any personal link with breast cancer. The new research, funded by the Medical Research Council, was conducted to get a better idea of the true risk level of these BRCA variants in the general population.

The authors analysed more than 454,000 participants recruited between the ages of 40 and 69 in the UK Biobank study, which collects DNA samples and asks participants to report illness in themselves as well as parents and siblings. They found that simply carrying a disease-causing BRCA variant was linked to a breast cancer risk of 18 per cent (for BRCA2) and 23 per cent (for BRCA1) by age 60. Having a close relative who has had the condition elevated the risk to 24 per cent (for BRCA2) and 45 per cent (for BRCA1) .

Lead author Dr Leigh Jackson, of the University of Exeter Medical School, said more women were choosing to have breast cancer surgery, particularly since actress Angelina Jolie shared her family history of the disease and subsequent genetic test and surgery. But he said: “Being told you are at high genetic risk of disease can really influence levels of fear of a particular condition and the resulting action you may take. Up to 80 per cent risk of developing breast cancer is very different from 20 per cent. That difference could well influence the decision you make around whether you have invasive breast surgery. Some women may decide to go ahead with that procedure knowing that the risk is 20 per cent, but we want them to make an informed decision. We’d urge that anyone communicating cancer risk does so based on a detailed family history, not just genetics alone.”

The research team found a similar result when looking at genetic risk of Lynch syndrome, a genetic condition which increases the risk of colon cancer and some other cancers. The authors also concluded that genetic screening for these conditions in the general population could result in large numbers of people being exposed to needless scans or further procedures.

Co-author Professor Caroline Wright, of the University of Exeter Medical School, said: “Our findings will not just apply to breast and colorectal cancer. All risk estimates of genetic disease have so far largely been based on relatively high-risk groups who attend specialist clinics, so they will not necessarily translate to the general population. This finding has important ramifications for population screening using genome sequencing. We need to ensure we are carrying out research to find the true risk level, and also to be responsible in how we communicate risk, to avoid unnecessary fear and distress which may lead to avoidable procedures.”

If you’re given a high genetic risk of any disease outside of a clinical setting, we’d advise you to speak to your doctor, who will be able to take into account a range of factors including family history to assess whether the risk may be worth investigating further.

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Cars, chlamydia and canines are biggest koala killers

A database tracking hospital admissions and deaths reveals the devastating impact cars, disease and dogs are having on the South East Queensland koala population.

Professor Joerg Henning and his colleagues at The University of Queensland School of Veterinary Science have analysed data from the UQ-developed KoalaBASE.

“Car strikes, dog attacks and chlamydia-induced illnesses are injuring and killing an incredible number of koalas across the South East Queensland,” Professor Henning said.

“In the five years between 2009 and 2014, 52 per cent of reported wild koala deaths were caused by car strike, 34 per cent were from a chlamydia-related disease and 14 per cent were because of a dog attack.

“This equates to 1,431 koala deaths from a car strike, 943 chlamydia-related deaths, and 395 dog attack deaths in just five years.

“Remember that these deaths were just the reported cases, so the real numbers would be significantly higher.”

KoalaBASE has been collecting data since 1997 across 15 local government areas from the Fraser Coast, to the Scenic Rim and Darling Downs and the South Burnett.

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Dr Ravi Dissanayake conducted the initial analysis, supervised by UQ colleagues and Professor Mark Stevenson at the University of Melbourne.

Data considered in the analysis included dog registration numbers, the human population and dwelling information, as well as road type and road length.

“This analysis is a useful starting point for more pro-active approaches to managing preventable wild koala mortality risk,” Professor Stevenson said.

“There are plenty of policies that could reduce car and dog impacts on South East Queensland’s dwindling wild koala populations.”

Professor Henning suggests that more road signs could alert motorists to reduce their speed in known koala habitat and activity areas.

“Construction of over and underpasses is also essential to ensure the safe movement of koalas through their habitat,” Professor Henning said.

“And information campaigns could help reduce the numbers of dog attacks on koalas by reminding owners to leash their dogs or keep them fenced in areas — it’s vitally important to reduce koala deaths caused by dogs.

“Our research included plenty of mapping, so we’re now keen to work with policymakers to identify specific areas where intervention efforts can help to reduce koala deaths.”

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Use a condom to avoid gonorrhoea, university students told

The sexually transmitted infection is at record levels in the UK and students are most at risk.

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Meditate to beat stress blood pressure, say guidelines

There is enough scientific evidence for some less conventional “body and mind” approaches, say experts.

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Scientists discover how brain cells die in Alzheimer’s

The findings, which had been a mystery for decades, give new ideas for treating the disease.

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Family provide free holidays in memory of son

Archie’s Caravan in Filey provides free holidays to families also facing childhood cancer.

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New evidence indicates patients recall death experiences after cardiac arrest

Up to an hour after their hearts had stopped, some patients revived by cardiopulmonary resuscitation (CPR) had clear memories afterward of experiencing death and had brain patterns while unconscious linked to thought and memory, report investigators in the journal Resuscitation, published by Elsevier.

In a study led by researchers at NYU Grossman School of Medicine, in cooperation with 25 mostly US and British hospitals, some survivors of cardiac arrest described lucid death experiences that occurred while they were seemingly unconscious. Despite immediate treatment, fewer than 10% of the 567 patients studied, who received CPR in the hospital, recovered sufficiently to be discharged. Four in 10 of patients who survived, however, recalled some degree of consciousness during CPR not captured by standard measures.

The study also found that in a subset of these patients, who received brain monitoring, nearly 40% had brain activity that returned to normal, or nearly normal, from a “flatline” state, at points even an hour into CPR. As captured by EEG, a technology that records brain activity with electrodes, the patients saw spikes in the gamma, delta, theta, alpha, and beta waves associated with higher mental function.

Survivors have long reported having heightened awareness and powerful, lucid experiences, say the study authors. These have included a perception of separation from the body, observing events without pain or distress, and a meaningful evaluation of their actions and relationships. This new work found these experiences of death to be different from hallucinations, delusions, illusions, dreams, or CPR-induced consciousness.

The study authors hypothesize that the “flatlined,” dying brain removes natural inhibitory (braking) systems. These processes, known collectively as disinhibition, may open access to “new dimensions of reality,” they say, including lucid recall of all stored memories from early childhood to death, evaluated from the perspective of morality. While no one knows the evolutionary purpose of this phenomenon, it “opens the door to a systematic exploration of what happens when a person dies.”

Senior study author Sam Parnia, MD, PhD, associate professor in the Department of Medicine at NYU Langone Health and director of critical care and resuscitation research at NYU Langone, says, “Although doctors have long thought that the brain suffers permanent damage about 10 minutes after the heart stops supplying it with oxygen, our work found that the brain can show signs of electrical recovery long into ongoing CPR. This is the first large study to show that these recollections and brain wave changes may be signs of universal, shared elements of so-called near-death experiences.”

Dr. Parnia adds, “These experiences provide a glimpse into a real, yet little understood dimension of human consciousness that becomes uncovered with death. The findings may also guide the design of new ways to restart the heart or prevent brain injuries and hold implications for transplantation.”

Called the AWAreness during REsuscitation (AWARE)-II study — it followed 567 men and women who suffered cardiac arrest during hospital stays between May 2017 and March 2020 in the United States and United Kingdom. Only hospitalized patients were enrolled to standardize the CPR and resuscitation methods used, as well as recording methods for brain activity. A subset of 85 patients received brain monitoring during CPR. Additional testimony from 126 community survivors of cardiac arrest with self-reported memories was also examined to provide greater understanding of the themes related to the recalled experience of death.

The study authors conclude that research to date has neither proved nor disproved the reality or meaning of patients’ experiences and claims of awareness in relation to death. They say the recalled experience surrounding death merits further empirical investigation and plan to conduct studies that more precisely define biomarkers of clinical consciousness and that monitor the long-term psychological effects of resuscitation after cardiac arrest.

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Snaps supersonic outflow of young star

Herbig-Haro (HH) objects are luminous regions surrounding newborn stars, formed when stellar winds or jets of gas spewing from these newborn stars form shock waves colliding with nearby gas and dust at high speeds. This image of HH 211 from NASA’s James Webb Space Telescope reveals an outflow from a Class 0 protostar, an infantile analog of our Sun when it was no more than a few tens of thousands of years old and with a mass only 8% of the present-day Sun (it will eventually grow into a star like the Sun).

Infrared imaging is powerful in studying newborn stars and their outflows, because such stars are invariably still embedded within the gas from the molecular cloud in which they formed. The infrared emission of the star’s outflows penetrates the obscuring gas and dust, making a Herbig-Haro object like HH 211 ideal for observation with Webb’s sensitive infrared instruments. Molecules excited by the turbulent conditions, including molecular hydrogen, carbon monoxide, and silicon monoxide, emit infrared light that Webb can collect to map out the structure of the outflows.

The image showcases a series of bow shocks to the southeast (lower-left) and northwest (upper-right) as well as the narrow bipolar jet that powers them. Webb reveals this scene in unprecedented detail — roughly 5 to 10 times higher spatial resolution than any previous images of HH 211. The inner jet is seen to “wiggle” with mirror symmetry on either side of the central protostar. This is in agreement with observations on smaller scales and suggests that the protostar may in fact be an unresolved binary star.

Earlier observations of HH 211 with ground-based telescopes revealed giant bow shocks moving away from us (northwest) and moving towards us (southeast) and cavity-like structures in shocked hydrogen and carbon monoxide respectively, as well as a knotty and wiggling bipolar jet in silicon monoxide. Researchers have used Webb’s new observations to determine that the object’s outflow is relatively slow in comparison to more evolved protostars with similar types of outflows.

The team measured the velocities of the innermost outflow structures to be roughly 48-60 miles per second (80 to 100 kilometers per second). However, the difference in velocity between these sections of the outflow and the leading material they’re colliding with — the shockwave — is much smaller. The researchers concluded that outflows from the youngest stars, like that in the center of HH 211, are mostly made up of molecules, because the comparatively low shock wave velocities are not energetic enough to break the molecules apart into simpler atoms and ions.

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