Posted on

Beyond what scientists already know about environmental factors

Podcast: Play in new window | Download

Subscribe: RSS

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/

Posted on

What sperm tells scientists about the origins of ASD

Podcast: Play in new window | Download

Subscribe: RSS

Does autism begin at a diagnosis, or before a diagnosis?  How early do genetics influence outcome?  This podcast explores a new angle to this question using studies in sperm.  One type of major ASD relevant mutation is de-novo mutations, meaning they are seen in the person with ASD but neither biological parent.  So where do they come from?  They may come from germ cells of the embryo of the parent, which forms the sperm and the egg.  Researchers from UCSD looked at mutations in sperm vs. blood in fathers of those with de-novo mutations and found an enrichment of genetic mutations in sperm.  This means the window of susceptibility can include not just things that happen at conception, but before conception.  Below is a graphic taken from a commentary of this study in Nature by Eric Morrow which may be helpful.

 

Posted on

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

Podcast: Play in new window | Download

Subscribe: RSS

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

 

Posted on

The Benefits of Being and Older Father

Podcast: Play in new window | Download

Subscribe: RSS

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.

Posted on

Narrowing down gene and environment interactions in autism

Podcast: Play in new window | Download

Subscribe: RSS

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.

Posted on

Oxytocin: hitting a small nail with a giant sledgehammer?

Podcast: Play in new window | Download

Subscribe: RSS

This week’s podcast is inspired by a new study in PNAS thatlooked at the role of methylation of the oxytocin receptor in social behavior in people without autism.  Together with studies of the brains of people with autism, it suggests that filling the brains with oxytocin may not be the best approach for treating social impairments.  Instead, compounds that turn on or turn off the genes that control oxytocin may be more appropriate, and it also may help explain variability in why some people respond to oxytocin treatment, and why others do not.   Also, scientific technology has a new way of studying the influence of the environment on brain development.

Posted on

Moving away from genes OR environment towards genes AND environment

Podcast: Play in new window | Download

Subscribe: RSS

On Thursday October 1st, Autism Science Foundation, Autism Speaks and the Escher Fund for Autism co-organized an online symposium which examined the possibility that early mutations in cells that pass along genetic information from generation to generation (sperm and egg and cells that make the sperm an egg) has a role in the causes of autism.  This symposium is on the ASF podcast feed, but a quick summary is presented on this week’s podcast.  Jill Escher from the Escher Fund for Autism and Mat Pletcher from Autism Speaks provide their perspective.  Also, a quick rundown on the study that caused so much monkeying around in the press.

Posted on

Early Germline Events in the Heritable Etiology of ASDs

Podcast: Play in new window | Download

Subscribe: RSS

On October 1st, Autism Science Foundation, Autism Speaks and the Escher Fund for Autism co-organized a webinar entitled “Early Germline Events in the Heritable Etiology of ASDs”.  The goal was to bring together researchers who study the germline (the sperm and the egg and all cells which pass down genetic information) and those studying the genetics of autism to determine how “de novo” or “new” genetic mutations are happening and how environment plays a role in genetics of autism and vice versa, rather than separating the concepts out into “either/or” .  This is part of an ongoing online symposium series on the epigenetics of autism.  Dr. Amander Clark from UCLA and Dr. Ryan Yuen from SickKids Hospital presented and a panel of experts including Lisa Chadwick from NIEHS, Patrick Allard from UCLA, Stephan Sanders from UCSF and Janine LaSalle from UCDavis commented.  We hope you enjoy the 2 hour webinar.