…..may be overestimating the risk of drowning and suffocation in those with ASD. The study claims a higher rate of drowning and other accidental deaths in people with autism, which is true, but the magnitude of the effect they found was astronomical and misleading given the methodology. They counted people with autism off of information on their death certificate. Not everyone with autism has this code listed on their death certificate – so likely this number is underestimated and the risk of drowning overestimated. The shocking results call for things like swimming lessons in those with autism and other drastic safety measures. People with autism ARE at a higher risk of drowning and we should all pay attention. Ways to prevent accidental death in people with autism are needed and the overall message should be the same. But the numbers themselves are probably a little off.
Last week, another Baby Siblings Research Consortium Project (BSRC) published an intriguing finding which also has the bonus of being a replication. Mark Shen, PhD, from the University of North Carolina at Chapel Hill found higher levels of extra axial fluid in the brains of infants who went on to later be diagnosed with autism, and even higher levels in those with severe autism symptoms. Extra-axial fluid is also called cerebrospinal fluid, the fluid that holds the brain steady in your head. Other functions of extra-axial fluid and what this means on how it may contribute to autism risk are described in the podcast. He not only explains the findings, but conveys what families should know about them and how they can help with early identification of ASD.
On March 13th, Dr. Mark Zylka from UNC gave a 60 minute overview of how researchers are using autism-relevant genetic mutations in cells to start to understand the interactions between genetics and thousands of environmental factors on gene expression. He pointed out the convergence of pathways in how genes and these environmental factors worked in the brain, and they included: neuroinflammation, early brain development, turning neurons on and off, and cell signaling. Dr. Valerie Hu from George Washington University commented on the important impact of these results and perspective from her lab studying epigenetically modified genes, like RORA, which also may be sensitive to common chemicals found in our environment. The entire webinar, including the questions that they were able to answer from participants, is found here.
On Monday, the much anticipated MSSNG study which analyzed the entire DNA sequence of over 5000 people with autism was published. The press release can be found here. In it, the researchers found even more genes of interest to autism. Also, those with more of a specific type of mutation, copy number variations, had worse autism symptoms. But of course, the story gets more complicated than just more mutations – worse behavior. An analysis from a different group of individuals reinforced the role of copy number variations in symptoms, but when they matched the groups according to IQ, the autism symptom profiles were different. This shows that adaptive behavior and IQ are important to consider when considering how genetics influence autism symptoms. Finally, another study shows how important measuring genetics is to understanding environmental factors associated with autism. Michela Traglia reports that increases in PBDEs in moms of kids affected with autism can be explained by mutations in the gene that breaks down these chemicals. It’s important to study genetics of autism, but also crucial to know the genetics of the entire family as well.
The brain is developing even after birth. So interventions that are given very early have the best chance of remolding and rewiring a brain with autism to prevent autism related disabilities. This week, a group from the University of London, Duke University and University of Washington measured brain activity during tasks that required social attention following 2 months of very very very early intervention. They found that the way the brain responded to social stimuli was more like those without an autism diagnosis. This study shows a biological marker of brain function is altered after behavioral interventions that are intended to do just that – change the way the brain functions.
Last month, UC Davis researcher Cyndi Schumann used resources for the Autism BrainNet to look at what causes differences in the rates of diagnosis between males and females. Consistent with other studies on this topic, males and females don’t show differences in the rates of autism genes, but rather in the way that the brain controls other genes that code for things like neuroinflammation and development. Clearly more studies are necessary but it is consistent with the Female Protective Effect in autism. The full text can be found here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5294827/
And also, there was a study on genital herpes and autism that CNN got totally wrong.
This week the Infant Brain Imaging Study, or IBIS, published it’s 2nd study on the emergence of changes in the brains of individuals with autism. While red flags for autism can be seen early, a diagnosis of autism is not typically made until after 24 months of age. Using a baby sibling research design, scientists showed increases in the size of certain areas of the brain between 6-12 months. This opens up opportunities for even earlier diagnosis of ASD in the future. Also, a group at Stanford shows the emergence and disappearance of co-morbid symptoms in autism, such as epilepsy, schizophrenia and ADHD, which are dependent on sex and age. Together, these studies show that autism begins very very early and symptoms and behavioral and biological features change over time.
This week two studies which examined infants and younger children that will significantly advance understanding of causes and services for people with autism were published. After a commentary about the confirmation of Betsy DeVos, the study that used a practical methodology to improve autism screening in pediatrics clinic from researchers at Duke University was presented. After that, some early results from the EARLI study which examined pregnancies in families where an older sibling was diagnosed was presented. In this study, Bo Park and her colleagues at Drexel University, Johns Hopkins University, University of California at Davis and Kaiser Permanente show that testosterone levels in pregnancy aren’t related to later autism symptoms unless the older sibling affected is a girl. These findings can illustrate why girls are less likely to be diagnosed with autism compared to boys. The study is open access and can be downloaded here, thanks to the journal Molecular Autism: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5282802/pdf/13229_2017_Article_118.pdf
Individual research studies are great. But even better is when someone takes these studies and puts them together to see if one study shows the same thing another does, and if they do is the effect size consistent? Sometimes you can only do this by going old school and pooling the data from the individual studies. This is especially helpful in determining the effectiveness of different interventions. This week, Dr. Matthew Lerner and his colleagues at Stony Brook University published a meta analysis of group social skills interventions. They put together well-designed studies and asked: do they work? Are they better than getting nothing at all? To find out, listen to this week’s ASF podcast.
With hundreds of genes, thousands of environmental factors, and now sex being variables in determining risk for autism, where should science start? Over the decades researchers have been able to start narrowing down the combinations based on specific behaviors of interest, genes, and mechanisms which may narrow down which gene, which environmental factor and which sex. Dr. Sara Schaafsma and Dr. Donald Pfaff from Rockefeller University combined the three, and found that epigenetic changes in an autism risk gene called contact in associated protein like 2 contributed to elevation of risk for autism behaviors following maternal infection. In other words, being male and having the mutation produced small changes, increased by the environmental factor. In another separate study, Dr. Keith Dunaway and Dr. Janine LaSalle at UC Davis used brain tissue to look at a rare variant for autism on chromosome 15. Typically, mutations of this area of the genome are thought to cause autism. However, the effects of these mutations are also increased when environmental factors are present, leading to more de novo mutations. These are all examples of scientific breakthroughs that are helping better understand what causes autism. Even when it looks like one thing, it’s multiple things.