More about the environmental influences in autism

New research points to a previously understudied but fascinating mechanism by which environmental factors may lead to autism: it’s called the “GABA/glutamate switch” which is a critical period in development when certain cells turn from turning on cell activity to turning them off. These environmental factors may delay this process leading to long term effects on the developing brain consistent with autism. While this data on the mechanism is brand new, the topic of the environment in autism was inspired by a recent effort at NIEHS which is developing an interactive database for people to access information about what environmental exposures have been studied and how in autism.

https://www.niehs.nih.gov/news/events/aware

https://www.pnas.org/doi/epub/10.1073/pnas.2406928121

A potential biomarker to AID, not MAKE, a diagnosis

The media has just called another biological marker a “diagnostic test”, when in this case, it was always intended to be an aid, not a test itself. It involves using baby hair strands to look a variation in metabolism of certain chemical elements across time. Remarkably, it showed similar results in autistic children in Japan, the US and Sweden. It’s not ready to be used as a diagnostic test, so what is it supposed to do? Listen to an interview with the inventor and researcher, Dr. Manish Arora from The Icahn School of Medicine at Mt. Sinai School here.

The full article (open access) can be found here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9740182/

What causes autism? Genetics or the Environment? Or maybe both?

Is it genes or is it the environment? or is it a combination? This question has plagued researchers and scientists and caused a lot of confusion in families about what caused their own or their child’s ASD. This week we review the mechanisms by which de-novo mutations could be the work of gene x environment interactions, and share new evidence of how SSRI’s do or don’t contribute to ASD through gene x environment interactions. We also want to recognize the valuable work of scientist Li-Ching Lee to these efforts. Dr. Lee recently passed away but will be sorely missed.

https://pubmed.ncbi.nlm.nih.gov/34002022/

https://pubmed.ncbi.nlm.nih.gov/34116791/

From being high to being aggressive

There are many many potential factors that influence a diagnosis of ASD that have been underexplored, and recreational drugs are one of them. Of course it would never explain all the cases of ASD, not one singular thing does, but does cannabis consumption during pregnancy lead to an increased probability of having a child with ASD? As it turns out, yes, a small increase, meaning it isn’t the only thing causing ASD but: JUST SAY NO if you are pregnant. On the other end of the spectrum is aggression, a completely horrible feature of some people with ASD. About 30% of people who are aggressive and have an ASD diagnosis are not responsive to any medications or therapies, which is horrifying. Researchers in Canada and Brazil have studied the brains of this group, with what is called “refractory aggression” to try to get to the mechanism.

https://pubmed.ncbi.nlm.nih.gov/32778828/

https://pubmed.ncbi.nlm.nih.gov/32762791/

Beyond what scientists already know about environmental factors

This week the ASF Podcast explores two ways to better understand the environmental influences in ASD diagnosis: 1. through potential cost savings of avoided cases of ASD due to reduced air pollution and 2. by studying pre-conception exposures going back as far as the grandparents exposure. These two concepts do not prove any one thing, including one environmental factor, causes ASD, however, using these approaches may improve understanding of ASD and allow for legislation that improves many health outcomes in children. Below are the two references:

https://pubmed.ncbi.nlm.nih.gov/32749866/

https://pubmed.ncbi.nlm.nih.gov/32704384/

Age of parents and ASD. It’s complicated.

Questions have loomed around the finding of an increased risk of parents having a child with ASD if they are under 20 or over 35. Of course not every parent who is really young or older will have a child on the spectrum and plenty of those between those ages also have children on the spectrum. Risk factors for ASD are not absolute, they are nuanced and work with other genetic and environmental factors. This week, Kristin Lyall from the AJ Drexel Autism Institute found that those with a strong genetic influence were not as sensitive to factors like parental age. This goes to show, yet again, that it isn’t about ONE risk factor, it’s about dozens working together. And for those 30 year old parents who had a child with autism – see, not every research finding applies to you directly.

https://www.ncbi.nlm.nih.gov/pubmed/32314879

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521130/

Genes and Environment, Genes and Environment. Go together like aging and retirement.

Twins with autism, where either one or both is diagnosed, is crucial to understand the role of genetics and the environment to both autism diagnoses and now, autism traits.  In a study this week, researchers using data from the California Twins Study examined the genetic and environmental influences of brain development in multiple regions and measures.  While estimates of genetic and environmental influences can only be modeled in twins, they can be experimentally tested in animal models.  Researchers at the University of Washington investigate what causes the link between air pollution in humans and autism by studying diesel fuel exhaust in pregnant mice.  Finally, across all of these disparate animal studies – does anything pull them together.  Are these models all one-offs or do they have anything in common?  It turns out disruption in normal brain activity is one thing that they have in common, and something that is at the common core of ASD neurobiology.

 

https://www.ncbi.nlm.nih.gov/pubmed/30659287

https://www.ncbi.nlm.nih.gov/pubmed/30668980

https://www.ncbi.nlm.nih.gov/pubmed/30679017

 

What are PCOS and DDT, and what do they have to do with autism?

Two new studies came out this week that implicates the role of the endocrine system in autism.  The endocrine system which regulates hormones in your body, also has a key role in brain development early on in fetal and child development.   PCOS is a metabolic condition and DDT is a toxic chemical banned years ago, but both are linked to the endocrine system, both are bad for many reasons, and both are linked to autism.  These studies provide evidence that we should #savetheEPA and be aware of medical and environmental factors which do not cause, but contribute to autism.  Also, PCOS is linked to autism in adult women, so ladies – if you show signs of PCOS, please talk to a doctor!

PCOS study:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6068102/  

DDT study:  https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.2018.17101129

PCOS blog:  https://www.rmanj.com/lifting-the-fog-on-polycystic-ovary-syndrome-pcos/

http://www.panna.org/resources/ddt-story

 

What is happening in research around employment for people with ASD?

This week, Melissa Scott from Curtin University, a partner in the international policy brief on employment for people with autism, discusses the first paper out of this collaboration:  a scoping review of the existing research out there on employment practices.  Surprisingly, there was one crucial element missing as a focus in all the intervention studies  –  the environment.  Dr. Scott discusses what else was learned from this scoping review, and how the findings can help people with autism not just obtain, but maintain employment, through constructive policy.   ASF is a proud partner on this policy brief, and Curtin University has been an amazing collaborator.

https://www.ncbi.nlm.nih.gov/pubmed/30073870

 

 

 

 

Ode to autism dads

On the heels of Father’s Day, this week’s podcast summarizes the last year or so of research which focuses on the fathers.  This includes genetics, parental stress and quality of life, and broader autism phenotype features.   Of note, two new studies that look at antidepressant exposure in father and probability of having a child with autism – a variation on studying maternal exposures.   For anyone interested, here is a list of references used:

 

https://www.ncbi.nlm.nih.gov/pubmed/28630308

https://www.ncbi.nlm.nih.gov/pubmed/28750543

https://www.ncbi.nlm.nih.gov/pubmed/29884724

https://www.ncbi.nlm.nih.gov/pubmed/25339495

https://www.ncbi.nlm.nih.gov/pubmed/29731598

https://www.ncbi.nlm.nih.gov/pubmed/29478155