Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.

April 24, 2012

Stress about wife's breast cancer can harm a man's health

COLUMBUS, Ohio – Caring for a wife with breast cancer can have a measurable negative effect on men's health, even years after the cancer diagnosis and completion of treatment, according to recent research. Men who reported the highest levels of stress in relation to their wives' cancer were at the highest risk for physical symptoms and weaker immune responses, the study showed. The researchers sought to determine the health effects of a recurrence of breast cancer on patients' male caregivers, but found that how stressed the men were about the cancer had a bigger influence on their health than did the current status of their wives' disease. The findings imply that clinicians caring for breast cancer patients could help their patients by considering the caregivers' health as well, the researchers say. This care could include screening caregivers for stress symptoms and encouraging them to participate in stress management, relaxation or other self-care activities, said Sharla Wells-Di Gregorio, lead author of the study and assistant professor of psychiatry and psychology at Ohio State University. "If you care for the caregiver, your patient gets better care, too," said Kristen Carpenter, a postdoctoral researcher in psychology at Ohio State and a study co-author LSW Continuing Education The research is published in a recent issue of the journal Brain, Behavior and Immunity. Thirty-two men participated in the study, including 16 whose wives had experienced a breast cancer recurrence an average of eight months before the study began and approximately five years after the initial cancer diagnosis. These men were matched with 16 men whose wives' cancers were similar, but who remained disease-free about six years after the initial diagnosis. The participants completed several questionnaires measuring levels of psychological stress related to their wives' cancers, physical symptoms related to stress, and the degree to which fatigue interfered with their daily functioning. Researchers tested their immune function by analyzing white-blood-cell activation in response to three different types of antigens, or substances that prompt the body to produce an immune response. The men's median age was 58 years and they had been married, on average, for 26 years. Almost all of the participants were white. In general, the men whose wives had experienced a recurrence of cancer reported higher levels of stress, greater interference from fatigue and more physical symptoms, such as headaches and abdominal pain, than did men whose wives had remained disease-free. The subjective stress assessment used in the study, called the Impact of Events Scale, measures intrusive experiences and thoughts, as well as attempts to avoid people and places that serve as painful reminders. The scale produces a score between 0 and 75; in this case, the higher the score, the more stressed the men were in relation to their wives' cancer. Overall, the men in the study produced an average score of 17.59. Men whose wives' cancer had recurred scored 26.25 as a group, and men whose wives were disease-free scored 8.94. According to the scale, scores above nine suggest a likely effect from the events, and scores between 26 and 43 indicate an event has had a powerful effect on a person's stress level. Scores over 33 suggest clinically significant distress. "The scores reported here are quite high, substantially higher than we see in our cancer patient samples outside the first year," Carpenter said. "Guilt, depression, fear of loss – all of those things are stressful. And this is not an acute stressor that lasts a few weeks. It's a chronic stress that lasts for years." The participants also reported, on average, a total of approximately seven stress-related physical symptoms. Men with wives with recurrent cancer reported nine symptoms, on average, and those whose wives were disease-free reported fewer than five symptoms, on average. These symptoms varied, but included headaches, gastrointestinal problems, coughing and nausea. When the analysis took into consideration the impact of men's perceived stress in relation to their wives' cancer, higher stress was associated with compromised immune function: Specifically, men with the highest scores on the stress scale also showed the lowest immune responses to two of the three antigens. Previous research has suggested that people with an impaired immune response are more susceptible to infection and might not respond well to vaccines. "Caregivers are called hidden patients because when they go in for appointments with their spouses, very few people ask how the caregiver is doing," said Wells-Di Gregorio, who works in Ohio State's Center for Palliative Care. "These men are experiencing significant distress and physical complaints, but often do not seek medical care for themselves due to their focus on their wives' illness." In these men undergoing chronic stress, the researchers said that it remains unclear whether the immune dysregulation causes more physical symptoms, or stress causes the symptoms and the impaired immune response. Wells-Di Gregorio noted that the stress effect might have been even more pronounced than what they observed because disease-free spouses were more reluctant to participate in the study. "We found that many were not willing to participate because they said they didn't want to think about cancer again," she said. This research was supported by the Ann and Herbert Siegel American Cancer Society Postdoctoral Fellowship, the Longaberger Company-American Cancer Society Grant for Breast Cancer Research, the U.S. Army Medical Research Acquisition Activity Grants, the National Institute of Mental Health and the National Cancer Institute. Co-authors included Caroline Dorfman and Hae-Chung Yang of Ohio State's Department of Psychology; Laura Simonelli of the Christiana Care Health System; and William Carson III of Ohio State's Department of Surgery and Comprehensive Cancer Center

April 23, 2012

Gatekeeper of brain steroid signals boosts emotional resilience to stress

PHILADELPHIA - A cellular protein called HDAC6, newly characterized as a gatekeeper of steroid biology in the brain, may provide a novel target for treating and preventing stress-linked disorders, such as depression and post-traumatic stress disorder (PTSD), according to research from the Perelman School of Medicine at the University of Pennsylvania. Glucocorticoids are natural steroids secreted by the body during stress. A small amount of these hormones helps with normal brain function, but their excess is a precipitating factor for stress-related disorders. Glucocorticoids exert their effects on mood by acting on receptors in the nucleus of emotion–regulating neurons, such as those producing the neurotransmitter serotonin. For years, researchers have searched for ways to prevent deleterious effects of stress by blocking glucocorticoids in neurons. However, this has proved difficult to do without simultaneously interfering with other functions of these hormones, such as the regulation of immune function and energy metabolism. In a recent Journal of Neuroscience paper, the lab of Olivier Berton, PhD, assistant professor of Psychiatry, shows how a regulator of glucocorticoid receptors may provide a path towards resilience to stress by modulating glucocorticoid signaling in the brain. The protein HDAC6, which is particularly enriched in serotonin pathways, as well as in other mood-regulatory regions in both mice and humans, is ideally distributed in the brain to mediate the effect of glucocorticoids on mood and emotions. HDAC6 likely does this by controlling the interactions between glucocorticoid receptors and hormones in these serotonin circuits ceus for social workers Experiments that first alerted Berton and colleagues to a peculiar role of HDAC6 in stress adaptation came from an approach that reproduces certain clinical features of traumatic stress and depression in mice. The animals are exposed to brief bouts of aggression from trained "bully" mice. In most aggression-exposed mice this experience leads to the development of a lasting form of social aversion that can be treated by chronic administration of antidepressants. In contrast, a portion of mice exposed to chronic aggression consistently express spontaneous resilience to the stress and do not develop any symptoms. By comparing gene expression in the brains of spontaneously resilient and vulnerable mice, Berton and colleagues discovered that reducing HDAC6 expression is a hallmark of naturally resilient animals. While aggression also caused severe changes in the shape of serotonin neurons and their capacity to transmit electrical signals in vulnerable mice, stress-resilient mice, in contrast, escaped most of these neurobiological changes. To better understand the link between HDAC6 and the development of stress resilience, Berton and colleagues devised a genetic approach to directly manipulate HDAC6 levels in neurons: Deletion of HDAC6 in serotonin neurons -- the densest HDAC6-expressing cell group in the mouse brain -- dramatically reduced social and anxiety symptoms in mice exposed to bullies and also fully prevented neurobiological changes due to stress, fully mimicking a resilient phenotype. Using biochemical assays, Berton's team showed it is by promoting reversible chemical changes onto a heat shock chaperone protein, Hsp90, that HDAC6 deletion is able to literally switch off the effects of glucocorticoid hormones on social and anxiety behaviors. Chaperones are proteins that help with the folding or unfolding and the assembly or disassembly of protein complexes. The way in which glucocorticoid receptor chaperoning and stress are linked is not well understood. Yet, genetic variations in certain components of the glucocorticoid receptor chaperone complex have been associated with the development of stress-related disorders and individual variability in therapeutic responses to antidepressants. "We provide pharmacological and genetic evidence indicating that HDAC6 controls certain aspects of Hsp90 structure and function in the brain, and thereby modulates protein interactions, as well as hormone- and stress-induced glucocorticoid receptor signaling and behavior," explains Berton. Together, these results identify HDAC6 as a possible stress vulnerability biomarker and point to pharmacological inhibition of HDAC6 as a potential new strategy for antidepressant interventions through regulation of Hsp90 in glucocorticoid signaling in serotonin neurons. Co-first-authors are Julie Espallergues and Sarah L. Teegarden, along with Avin Veerakumar, Janette Boulden, Collin Challis, Jeanine Jochems, Michael Chan, Tess Petersen, Chang-Gyu Hahn, Irwin Lucki, and Sheryl G. Beck, all from Penn. Other authors are Evan Deneris, from Case Western Reserve University, Cleveland, Ohio, and Patrick Matthias, Miescher Institute for Biomedical Research, Basel, Switzerland. This work was funded by the National Institute of Mental Health grants MH087581 and MH0754047 and grants from the International Mental Health Research Organization and the National Alliance for Research on Schizophrenia and Depression. Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $4.3 billion enterprise. The Perelman School of Medicine is currently ranked #2 in U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $479.3 million awarded in the 2011 fiscal year. The University of Pennsylvania Health System's patient care facilities include: The Hospital of the University of Pennsylvania -- recognized as one of the nation's top 10 hospitals by U.S. News & World Report; Penn Presbyterian Medical Center; and Pennsylvania Hospital - the nation's first hospital, founded in 1751. Penn Medicine also includes additional patient care facilities and services throughout the Philadelphia region. Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2011, Penn Medicine provided $854 million to benefit our community.

April 22, 2012

Phobia's effect on perception of feared object allows fear to persist

COLUMBUS, Ohio – The more afraid a person is of a spider, the bigger that individual perceives the spider to be, new research suggests. In the context of a fear of spiders, this warped perception doesn't necessarily interfere with daily living. But for individuals who are afraid of needles, for example, the conviction that needles are larger than they really are could lead people who fear injections to avoid getting the health care they need. A better understanding of how a phobia affects the perception of feared objects can help clinicians design more effective treatments for people who seek to overcome their fears, according to the researchers. In this study, participants who feared spiders were asked to undergo five encounters with live spiders – tarantulas, in fact – and then provide size estimates of the spiders after those encounters ended. The more afraid the participants said they were of the spiders, the larger they estimated the spiders had been. "If one is afraid of spiders, and by virtue of being afraid of spiders one tends to perceive spiders as bigger than they really are, that may feed the fear, foster that fear, and make it difficult to overcome," said Michael Vasey, professor of psychology at Ohio State University and lead author of the study. "When it comes to phobias, it's all about avoidance as a primary means of keeping oneself safe. As long as you avoid, you can't discover that you're wrong. And you're stuck. So to the extent that perceiving spiders as bigger than they really are fosters fear and avoidance, it then potentially is part of this cycle that feeds the phobia that leads to its persistence continuing education for social workers "We're trying to understand why phobias persist so we can better target treatments to change those reasons they persist." The study is published in a recent issue of the Journal of Anxiety Disorders. The researchers recruited 57 people who self-identified as having a spider phobia. Each participant then interacted at specific time points over a period of eight weeks with five different varieties of tarantulas varying in size from about 1 to 6 inches long. The spiders were contained in an uncovered glass tank. Participants began their encounters 12 feet from the tank and were asked to approach the spider. Once they were standing next to the tank, they were asked to guide the spider around the tank by touching it with an 8-inch probe, and later with a shorter probe. Throughout these encounters, researchers asked participants to report how afraid they were feeling on a scale of 0-100 according to an index of subjective units of distress. After the encounters, participants completed additional self-report measures of their specific fear of spiders, any panic symptoms they experienced during the encounters with the spiders, and thoughts about fear reduction and future spider encounters. Finally, the research participants estimated the size of the spiders – while no longer being able to see them – by drawing a single line on an index card indicating the length of the spider from the tips of its front legs to the tips of its back legs. An analysis of the results showed that higher average peak ratings of distress during the spider encounters were associated with estimates that the spiders were larger than they really were. Similar positive associations were seen between over-estimates of spider size and participants' higher average peak levels of anxiety, higher average numbers of panic symptoms and overall spider fear. These findings have been supported in later studies with broader samples of people with varying levels of fear of spiders. "It would appear from that result that fear is driving or altering the perception of the feared object, in this case a spider," said Vasey, also the director of research for the psychology department's Anxiety and Stress Disorders Clinic. "We already knew fear and anxiety alter thoughts about the feared thing. For example, the feared outcome is interpreted as being more likely than it really is. But this study shows that even perception is altered by fear. In this case, the feared spider is seen as being bigger. And that may serve as a maintaining factor for the fear." The approach tasks with the spiders are a classic example of exposure therapy, a common treatment for people with phobias. Though this therapy is known to be effective, scientists still do not fully understand why it works. And for some, the effects don't last – but it is difficult to predict who will have a relapse of fear, Vasey said. He and colleagues are studying these biased perceptions as well as attitudes with hopes that the new knowledge will enhance treatment for people with various phobias. The work suggests that fear not only alters one's perception of the feared thing, but also can influence a person's automatic attitude toward an object. Those who have developed an automatic negative attitude toward a feared object might have a harder time overcoming their fear. Though individuals with arachnophobia are unlikely to seek treatment, the use of spiders in this research was a convenient way to study the complex effects of fear on visual perception and how those effects might cause fear to persist, Vasey noted. "Ultimately, we are interested in identifying predictors of relapse so we can better measure when a person is done with treatment," he said. This work is supported by the National Institute of Mental Health. Co-authors include Michael Vilensky, Jacqueline Heath, Casaundra Harbaugh, Adam Buffington and Vasey's principal collaborator, Russell Fazio, all of Ohio State's Department of Psychology.

April 18, 2012

Genetic manipulation boosts growth of brain cells linked to learning, enhances antidepressants


DALLAS -- UT Southwestern Medical Center investigators have identified a genetic manipulation that increases the development of neurons in the brain during aging and enhances the effect of antidepressant drugs.

The research finds that deleting the Nf1 gene in mice results in long-lasting improvements in neurogenesis, which in turn makes those in the test group more sensitive to the effects of antidepressants.

"The significant implication of this work is that enhancing neurogenesis sensitizes mice to antidepressants – meaning they needed lower doses of the drugs to affect 'mood' – and also appears to have anti-depressive and anti-anxiety effects of its own that continue over time," said Dr. Luis Parada, director of the Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration and senior author of the study published in the Journal of Neuroscience.

Just as in people, mice produce new neurons throughout adulthood, although the rate declines with age and stress, said Dr. Parada, chairman of developmental biology at UT Southwestern. Studies have shown that learning, exercise, electroconvulsive therapy and some antidepressants can increase neurogenesis. The steps in the process are well known but the cellular mechanisms behind those steps are not.

"In neurogenesis, stem cells in the brain's hippocampus give rise to neuronal precursor cells that eventually become young neurons, which continue on to become full-fledged neurons that integrate into the brain's synapses," said Dr. Parada, an elected member of the prestigious National Academy of Sciences, its Institute of Medicine, and the American Academy of Arts and Sciences.

The researchers used a sophisticated process to delete the gene that codes for the Nf1 protein only in the brains of mice, while production in other tissues continued normally. After showing that mice lacking Nf1 protein in the brain had greater neurogenesis than controls, the researchers administered behavioral tests designed to mimic situations that would spark a subdued mood or anxiety, such as observing grooming behavior in response to a small splash of sugar water.

The researchers found that the test group mice formed more neurons over time compared to controls, and that young mice lacking the Nf1 protein required much lower amounts of anti-depressants to counteract the effects of stress. Behavioral differences between the groups persisted at three months, six months and nine months. "Older mice lacking the protein responded as if they had been taking antidepressants all their lives," said Dr. Parada.

"In summary, this work suggests that activating neural precursor cells could directly improve depression- and anxiety-like behaviors, and it provides a proof-of-principle regarding the feasibility of regulating behavior via direct manipulation of adult neurogenesis," Dr. Parada said.

Dr. Parada's laboratory has published a series of studies that link the Nf1 gene – best known for mutations that cause tumors to grow around nerves – to wide-ranging effects in several major tissues. For instance, in one study researchers identified ways that the body's immune system promotes the growth of tumors, and in another study, they described how loss of the Nf1 protein in the circulatory system leads to hypertension and congenital heart disease social worker ceus

The current study's lead author is former graduate student Dr. Yun Li, now a postdoctoral researcher at the Massachusetts Institute of Technology. Other co-authors include Yanjiao Li, a research associate of developmental biology, Dr. Renée McKay, assistant professor of developmental biology, both of UT Southwestern, and Dr. Dieter Riethmacher of the University of Southampton in the United Kingdom.

The study was supported by the National Institutes of Health's National Institute of Neurological Disorders and Stroke, and National Institute of Mental Health. Dr. Parada is an American Cancer Society Research Professor.

This news release is available on our World Wide Web home page at www.utsouthwestern.edu/home/news/index.html

To automatically receive news releases from UT Southwestern via email, subscribe at www.utsouthwestern.edu/receivenews

April 15, 2012

Excessive worrying may have co-evolved with intelligence


What is usually seen as pathology may aid survival of the species

Worrying may have evolved along with intelligence as a beneficial trait, according to a recent study by scientists at SUNY Downstate Medical Center and other institutions. Jeremy Coplan, MD, professor of psychiatry at SUNY Downstate, and colleagues found that high intelligence and worry both correlate with brain activity measured by the depletion of the nutrient choline in the subcortical white matter of the brain. According to the researchers, this suggests that intelligence may have co-evolved with worry in humans.

"While excessive worry is generally seen as a negative trait and high intelligence as a positive one, worry may cause our species to avoid dangerous situations, regardless of how remote a possibility they may be," said Dr. Coplan. "In essence, worry may make people 'take no chances,' and such people may have higher survival rates. Thus, like intelligence, worry may confer a benefit upon the species."

In this study of anxiety and intelligence, patients with generalized anxiety disorder (GAD) were compared with healthy volunteers to assess the relationship among intelligence quotient (IQ), worry, and subcortical white matter metabolism of choline. In a control group of normal volunteers, high IQ was associated with a lower degree of worry, but in those diagnosed with GAD, high IQ was associated with a greater degree of worry. The correlation between IQ and worry was significant in both the GAD group and the healthy control group. However, in the former, the correlation was positive and in the latter, the correlation was negative. Eighteen healthy volunteers (eight males and 10 females) and 26 patients with GAD (12 males and 14 females) served as subjects.

Previous studies have indicated that excessive worry tends to exist both in people with higher intelligence and lower intelligence, and less so in people of moderate intelligence. It has been hypothesized that people with lower intelligence suffer more anxiety because they achieve less success in life.

The results of their study, "The Relationship between Intelligence and Anxiety: An Association with Subcortical White Matter Metabolism," was published in a recent edition of Frontiers in Evolutionary Neuroscience, and can be read at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3269637/pdf/fnevo-03-00008.pdf.

The study was selected and evaluated by a member of the Faculty of 1000 (F1000), placing it in their library of the top 2% of published articles in biology and medicine.

SUNY Downstate Medical Center, founded in 1860, was the first medical school in the United States to bring teaching out of the lecture hall and to the patient's bedside. A center of innovation and excellence in research and clinical service delivery, SUNY Downstate Medical Center comprises a College of Medicine, Colleges of Nursing and Health Related Professions, a School of Graduate Studies, a School of Public Health, University Hospital of Brooklyn, and an Advanced Biotechnology Park and Biotechnology Incubator.

SUNY Downstate ranks eighth nationally in the number of alumni who are on the faculty of American medical schools. More physicians practicing in New York City have graduated from SUNY Downstate than from any other medical school social worker continuing education

April 11, 2012

Mothers and OCD children trapped in rituals have impaired relationships

News Release: Tuesday, April 10, 2012



A new study from Case Western Reserve University finds mothers tend to be more critical of children with obsessive-compulsive disorder than they are of other children in the family. And, that parental criticism is linked to poorer outcomes for the child after treatment.

Parent criticism has been associated with child anxiety in the past, however, researchers wanted to find out if this is a characteristic of the parent or something specific to the relationship between the anxious child and the parent.

“This suggests that mothers of anxious children are not overly critical parents in general. Instead they seem to be more critical of a child with OCD than they are of other children in the home,” said Amy Przeworski, assistant professor of psychology. She is the lead author of the study, “Maternal and Child Expressed Emotion as Predictors of Treatment Response in Pediatric Obsessive-Compulsive Disorder,” in the recent journal, Child Psychiatry & Human Development.

OCD is found in one in 200 children, according to the American Academy of Child and Adolescent Psychiatry. The psychological disorder overcomes individuals with repetitive thoughts that lead to anxiety, which is then acted out in exacting routines or behaviors that can range from foot tapping to eating rituals to school or bedtime preparations.

This research evolved from other studies that found parental criticism is associated with less success in therapy and a relapse of behavior.

“Parents’ criticism may be a reaction to the child’s anxiety. This research is not blaming the parent for the child’s OCD. But it does suggest that the relationship between parents and children with OCD is important and should be a focus of treatment. This means that parents can help children with OCD to get better.” Przeworski says.

“OCD sneaks up on the kids and parents,” Przeworski says.

The psychology professor, who specializes in anxiety disorders, says some parents become concerned when their children show some early warning signs for OCD:

• Rigidity in a child, with things routinely done or said in exactly the same way or order.
• Asking for reassurance many times in the day.
• Repetition of a task from tapping the foot, checking on the stove, washing hands that the child cannot stop when asked.
• Routines that have prescribed patterns or are excessive lengthy: An example is a two-hour shower or raw and chapped hands that look like the child is wearing red gloves.
• Bedtime or dinner rituals, where there is a prescribed order for eating food, placement of food on the plate, etc.
• Temper tantrums where the child goes beyond being stubborn but has anxiety associated with them.
• Children want symmetry in appearance or things around them.

Parents initially may think it is a phase, a habit or stubbornness. Over time, the behaviors become so exacting that the child and family members have to act in prescribed ways. Parents may end up criticizing the child in an effort to get them to drop obsessive-compulsive behaviors.

The researchers videotaped interviews with 62 mother-child pairs just before the child’s OCD treatment began. Children either had medication, therapy, a combination of the two, or a placebo. The children were between the ages of 7 and 17.

Because most mothers bring their children for treatment appointments, the researchers focused on the mother’s view of their children. Mothers were asked to give a five-minute description of their relationship with the child with OCD and the mother’s relationship with the sibling closest in age to the child with OCD. The researchers asked the children to describe their relationships with their mothers and fathers.

The researchers examined the presence of criticism and emotional over-involvement (over-protection or excessive self-sacrificing) in these descriptions. The tone of the OCD child and parent tended toward criticism, they said. The other sibling received more loving expressions. Parent criticism was associated with poorer child functioning after treatment.

Przeworski said treatment of OCD has good results, but many times parents misjudge these rigid routines as stubbornness or “just going through a phase” until the behavior takes over family life. Then parents realize the behavior requires therapy professional counselor continuing education

Collaborating with Przeworski were: Lori Zoellner from University of Washington; Martin E. Franklin and Edna B. Foa, University of Pennsylvania School of Medicine; and Abbe Garcia and Jennifer Freeman, Brown University. The study was supported with funds from the National Institute of Mental Health.


Posted by: Susan Griffith, April 10, 2012 01:19 PM | News Topics: Official Release

April 08, 2012

Spontaneous Gene Glitches Linked to Autism Risk with Older Dads


Non-Inherited Mutations Spotlight Role of Environment – NIH-Supported Study, Consortium ceus for nurses

Researchers have turned up a new clue to the workings of a possible environmental factor in autism spectrum disorders (ASDs): fathers were four times more likely than mothers to transmit tiny, spontaneous mutations to their children with the disorders. Moreover, the number of such transmitted genetic glitches increased with paternal age. The discovery may help to explain earlier evidence linking autism risk to older fathers.

The results are among several from a trio of new studies, supported in part by the National Institutes of Health, finding that such sequence changes in parts of genes that code for proteins play a significant role in ASDs. One of the studies determined that having such glitches boosts a child’s risk of developing autism five to 20 fold.

Taken together, the three studies represent the largest effort of its kind, drawing upon samples from 549 families to maximize statistical power. They reveal sporadic mutations widely distributed across the genome, sometimes conferring risk and sometimes not. While the changes identified don’t account for most cases of illness, they are providing clues to the biology of what are likely multiple syndromes along the autism spectrum.

“These results confirm that it’s not necessarily the size of a genetic anomaly that confers risk, but its location – specifically in biochemical pathways involved in brain development and neural connections. Ultimately, it’s this kind of knowledge that will yield potential targets for new treatments,” explained Thomas, R. Insel, M.D., director of the NIH’s National Institute of Mental Health (NIMH), which funded one of the studies and fostered development of the Autism Sequencing Consortium, of which all three groups are members.

Multi-site research teams led by Mark Daly, Ph.D., of the Harvard/MIT Broad Institute, Cambridge, Mass., Matthew State, M.D., Ph.D., of Yale University, New Haven, Conn., and Evan Eichler, Ph.D., of the University of Washington, Seattle, report on their findings online April 4, 2012 in the journal Nature.

The study by Daly and colleagues was supported by NIMH – including funding under the American Recovery and Reinvestment Act. The State and Eichler studies were primarily supported by the Simons Foundation Autism Research Initiative. The studies also acknowledge the NIH’s National Human Genome Research Institute, National Heart Lung and Blood Institute, and National Institute on Child Health and Human Development and other NIH components.

All three teams sequenced the protein coding parts of genes in parents and an affected child – mostly in families with only one member touched by autism. One study also included comparisons with healthy siblings. Although these protein-coding areas represent only about 1.5 percent of the genome, they harbor 85 percent of disease-causing mutations. This strategy optimized the odds for detecting the few spontaneous errors in genetic transmission that confer autism risk from the “background noise” generated by the many more benign mutations.

Like larger deletions and duplications of genetic material previously implicated in autism and schizophrenia, the tiny point mutations identified in the current studies are typically not inherited in the conventional sense – they are not part of parents’ DNA, but become part of the child’s DNA. Most people have many such glitches and suffer no ill effects from them. But evidence is building that such mutations can increase risk for autism if they occur in pathways that disrupt brain development.

State’s team found that 14 percent of people with autism studied had suspect mutations – five times the normal rate. Eichler and colleagues traced 39 percent of such mutations likely to confer risk to a biological pathway known to be important for communications in the brain.

Although Daly and colleagues found evidence for only a modest role of the chance mutations in autism, those pinpointed were biologically related to each other and to genes previously implicated in autism.

The Eichler team turned up clues to how environmental factors might influence genetics. The high turnover in a male’s sperm cells across the lifespan increases the chance for errors to occur in the genetic translation process. These can be passed-on to the offspring’s DNA, even though they are not present in the father’s DNA. This risk may worsen with aging. The researchers discovered a four-fold marked paternal bias in the origins of 51 spontaneous mutations in coding areas of genes that was positively correlated with increasing age of the father. So such spontaneous mutations could account for findings of an earlier study that found fathers of boys with autism were six times – and of girls 17 times – more likely to be in their 40’s than their 20’s.

“We now have a path forward to capture a great part of the genetic variability in autism – even to the point of being able to predict how many mutations in coding regions of a gene would be needed to account for illness,” said Thomas Lehner, Ph.D., chief of the NIMH Genomics Research Branch, which funded the Daly study and helped to create the Autism Sequencing Consortium. “These studies begin to tell a more comprehensive story about the molecular underpinnings of autism that integrates previously disparate pieces of evidence.”

References

Sanders SJ, Murtha MT, Gupta AR, Murdoch JD, Raubeson MJ, Willsey AJ, Ercan-Sencicek AG, DiLullo NM, Parikshak NN, Stein JL, Walker MF, Ober GT, Teran NA, Song Y, El-Fishawy P, Murtha RC, Choi M, Overton JD, Bjornson RD, Carriero NJ, Meyer KA, Bilguvar K, Mane SM, Sestan N, Lifton RP, GĂ¼nel M, Roeder K, Geschwind DH, Devlin B, State MW. De novo mutations revealed by whole-exome sequencing are strongly associated with autism. April 5, 2012. Nature.

O’Roak BJ, Vives L, Girirajan S, Karakoc E, Krumm N, Coe BP, Levy R, Ko A, Lee C, Smith JD, Turner EH, Stanaway IB, Vernot B, Malig M, Baker C, Reilly B, Akey JM, Borenstein E, Rieder MJ, Nickerson DA, Bernier R, Shendure J, Eichler EE. Sporadic autism exomes reveal a highly interconnected protein network of de novo mutations. Nature. April 5, 2012.

Neale BM, Kou Y, Liu L, Ma’ayan A, Samocha KE, Sabo A, Lin CF, Stevens C, Wang LS, Makarov V, Polak P, Yoon S, Maguire J, Crawford EL, Campbell NG, Geller ET, Valladares O, Schafer C, Liu H, Zhao T, Cai G, Lihm J, Dannenfelser R, Jabado O, Peralta Z, Nagaswamy U, Muzny D, Reid JG, Newsham I, Wu Y, Lewis L, Han Y, Voight BF, Lim E, Rossin E, Kirby A, Flannick J, Fromer M, Shair K, Fennell T, Garimella K, Banks E, Poplin R, Gabriel S, DePristo M, Wimbish JR, Boone BE, Levy SE, Betancur C, Sunyaev S, Boerwinkle E, Buxbaum JD, Cook EH, Devlin B, Gibbs RA, Roeder K, Schellenberg GD, Sutcliffe JS, Daly MJ. Patterns and rates of exonic de novo mutations in autism spectrum disorders. Nature. April 5, 2012.

###

The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.