This week a bunch of new studies came out that focused on changes in probability of having a child with autism after folic acid consumption during pregnancy. Moderate consumption folic acid and slightly elevated levels of plasma folate during pregnancy has now been shown in at least half a dozen scientific studies to reduce the chance of that child to be later diagnosed with autism. This is not a prevention effect, but a reduction in probability. There are enough studies on this question for a Chinese group to have organized them, put their data together, reanalyze them together and conclude that this is a real thing. If this was an effect seen after say, drinking battery acid, maybe it might require more consideration to recommend to the community. However, taking folic acid during pregnancy is something medical doctors are recommending pregnant women do anyway.
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.
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.
Scientists have studied males compared to females with autism, but rarely has there been studies about what clinicians see as differences in these two groups. Given that they provide insight on diagnosis, needs and access to services, it is kind of important to talk to them, and a study out this week in the journal Autism did just that. You can find the full text here:
Also, scientists are starting to understand the role of exposures in parents and how they affect diagnosis of autism in their children, but this week a new wrench was thrown into the wheel: researchers in the UK found that grandparental exposures play a role in autism diagnosis too. Luckily, this too is open access and you can read it for yourself. It was covered in the media and we have perspective from a parent included.
I discuss this second project with Jill Escher, founder of the Escher Fund for Autism and co-funder of the study.
As always, good news and bad news in autism this week. First the good news: an intervention given between 9-14 months of age in children with a high probability of having an autism diagnosis improved autism symptoms at 3 years of age. Now the bad: mothers who experience severe childhood abuse are more likely to have a child with an autism diagnosis. Why? A new study explains it might have a lot to do with autism traits in the parents. We would love to hear your thoughts on the results, please provide them in the comment section.
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)
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
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.
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.