Every time you turn around there is another study contradicting the last on antidepressant use and autism risk. An answer on why there are differences across different studies may be found in a new analysis published by University of Washington and SSM Dean Medical Group in Wisconsin this week. They showed that autism severity (not risk) is increased only with both a likely gene disruption AND following antidepressant exposure in pregnancy together. This suggests a double hit model similar to other complex neuropsychiatric disorders like depression. It also suggests that findings from other chemicals, like PBDE’s, may be dependent on gene / environment interactions too. After all, a new systematic review showed PBDE’s during pregnancy are bad for the IQ of the child. This provides insight on ASD risk and subtype given the multitude of possible genetic / environmental combinations out there.
Advanced paternal age is one of the more replicated risk factors for autism – but maybe not autism as it as seen as a disorder. Recent studies by Mount Sinai School of Medicine and Kings College of London show in both animal models and in epidemiological studies that advanced age in fathers is associated with the “active but odd” phenotype and PDD NOS. In people, older (but not “old”) age in fathers led to increased IQ and social aloofness that led to higher academic achievement. Is this autism? Or just a subtype of autism where the outcomes are adaptive rather than maladaptive? There are lots of questions about the nature of autism in these findings.
Two studies of importance came out this week. The first looked at the interactive effects of genetic mutations called copy number variations and air pollution. Previously, ozone was not listed in the factors in air pollution that increased risk for autism. But combine it with copy number variations – now the two together dramatically increase risk. Ozone levels are something that can be reduced through legislation. Second, the role of internet addiction is generally not acknowledged or appreciated, but a recent study demonstrated that people with autism show triple the rate of internet addiction compared to those without autism. This is something that psychiatrists and psychologists should know about when they think about treatments and comorbidities of people with ASD.
On May 4th, Dr. Janine LaSalle from UC Davis and (the soon to be Dr.) Keith Dunaway presented on recent research investigating the role of environmental factors in individuals with Dup15 Syndrome. Individuals with a mutation on chromosome 15 are often diagnosed with autism and previously it had been assumed that these individuals were destined to have a diagnosis due to their genetics. Dr. LaSalle shows that many of the genes in a critical region of chromosome 15 are tied to turning genes on and off via a process called methylation. Environmental chemicals or other exposures may also work on these genes to turn on or off gene expression epigenetically. The first half of the webinar reviews crucial ideas in gene x environment interactions and epigenetics, the second half describes experiments using brain tissue of those with Dup15 Syndrome and autism, as well as cell lines, to understand the role of PCBs in gene expression.
On Thursday, March 30th the Autism Science Foundation held their 4th Annual Day of Learning in NYC. If you were not able to attend and can’t wait for the videos of the talks, this week’s podcast attempts to summarize what was presented.
A list of the talks are:
- Autism Research: Where Are We Now? – Dr. Wendy Chung (Simons Foundation)
- Housing Options for Adults with Autism – Amy Lutz (EASI Foundation)
- Improving Communication Between Parents of Children with Autism and Teachers – Dr. David Mandell (University of Pennsylvania)
- Developing Clinical Biomarkers – Dr. James McPartland – (Yale University)
- Understanding Modifiable Autism Risk Factors – Dr. Craig Newschaffer (Drexel University)
- Helping People with Autism Develop Practical Skills – Dr. Celine Saulnier (Emory University)
- New Technologies to Improve Autism Diagnosis – Dr. Robert Schultz (Children’s Hospital of Philadelphia)
- Understanding the Female Protective Effect – Dr. Donna Werling (University of California, San Francisco)
David Mandell’s presentation on parent/teacher communication was based, in part, on this publication: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676744/
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.
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
Happy New Year! Over the holiday break, a the largest study so far including the most number of countries analyzed the risk of having a c-section and autism. They found a consistent increase risk that wasn’t due to cause of the c-section or the age of the infant (preemie or term). So what is going on? This week’s podcast warns against the unintended consequences of linking c-sections to autism and offers an explanation of the findings in addition to what the study authors provide.
The year 2016 was eventful for many reasons. In this 20 minute podcast, we review some of the scientific discoveries that highlighted findings in causes, understanding, and treating ASD. Featured more this year is studies on the sibling of individuals with ASD, so we are calling 2016 “The Year of the Sibling” This review includes genetics, gene x environment interactions, diagnosis, the broader autism phenotype, and early interventions and the role of parent-delivered interventions in long term outcome. It also highlights the important role of studying brain tissue from individuals with autism to better understand people with autism across the lifespan, including those with known causes and unknown causes of ASD. We hope you find it informative – please send comments to firstname.lastname@example.org
On Tuesday November 15th, Tracy Bale from University of Pennsylvania provided an insightful analysis of sex differences in behavioral, physiological and molecular outcomes following prenatal stress. She outlined the potential epigenetic markers that may lead to resilience in female offspring which has direct implications for autism. However, prior to Dr. Bale’s presentation, Donna Werling from UCSF briefly outlined the genetic and behavioral data so far about females with autism and why there is a 4:1 ratio in males to females getting a diagnosis. This webinar is part of the Environmental Epigenetics of Autism Webinar Series co-organized by Autism Science Foundation, Autism Speaks and the Escher Family Fund for Autism.