Yes, another type of mutation in autism was revealed this week. Those that are evident after the sperm and egg meet to form the zygote but still very early, during embryonic development. Because it occurs after the original zygote is formed, the mutation is not found in every cell or every region of the body, called post-zygotic. A collaboration of three major genetic consortia studied and collaborated on these types of mutations and revealed that they consist of about 7.5% of all de novo mutations in people with autism. They affect autism risk genes and selectively target brain regions associated with autism. Learn more about what this means for family planning and cognitive ability in people with autism.
In order to ensure that researchers have enough brain tissue to understand autism spectrum disorders, the education and outreach campaign is being expanded past families to doctors and professionals that have access to tissue. One of these groups is neuropathologists. At their annual meeting this past week in Los Angeles, and entire afternoon was spent dedicated to autism and the features of autism in the brain. A summary of the presentations is included in this podcast. Speakers emphasized that the way the brain works in childhood is not the same way it works in adulthood, and a study out of UCSD showed that the genes that are affected in children with autism are different than those in adults with autism. The mechanisms of genes controlling the developing brain vs. those which affect ongoing maintenance are different. This calls to make sure scientists understand all ages of people with autism, because as the brain changes, so do the needs of people with ASD.
Lots of people tend to think of the genetics of disorders or disease about one mutation or genetic variation that is inherited from the mother or the father, that causes a trait directly. Unfortunately, the genetics of autism isn’t that simple or scientists would have found “the gene” by now. In fact, there are different types of genetic influences in autism. A new study in Nature Genetics led by Elise Robinson shows how common variation influences autism risk, as well as intellectual function in autism, compared to de novo mutations. There is a short primer at the beginning of the podcast about old-school genetic thinking and why it doesn’t apply to ASD. Below is the picture mentioned.
This week’s International Meeting for Autism Research was filled with important presentations on the multiple causes of autism, interventions, diagnosis, neurobiology, services, family and self-advocate perspectives, the list goes on and on. There is a great recap on www.spectrumnews.org. An underlying theme ran through the presentations. That is, that the previous “well, we don’t see differences because there is lots of heterogeneity in autism” explanation isn’t cutting it anymore. We know people with autism are different, and parents, self-advocates and researchers are starting to deal with it by stratifying groups by their genetic backgrounds. While not a complete solution to this challenge, research at IMFAR shows that identifying different subgroups based on genetics is helping to explain symptoms.
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 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.
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.
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 December 13, 2016, Dr. Matthew Anderson from Beth Isreal Deaconess Medical Center presented a 45 minute webinar on recent findings in autism thanks to studying the brains of people with autism. It covers genetics, neuropathology and immunology. It’s a great chance to hear a quick recap of findings from an Autism BrainNet node director. Please click above to watch the 45 minute presentation and questions from the audience. Most importantly, anyone can be a part of this important research by registering to learn more about the Autism BrainNet at www.takesbrains.org.
A gene that controls electrical activity in the brain, SCN2A, has been linked to autism for awhile. But recently, a new study from China shows that mutations of this gene are seen in about 1% of people with autism. This may put it into the category of the rare mutations that have a major contribution to autism symptoms. In addition to autism, mutations of these gene are associated with seizures and epilepsy. Because of the relatively high rates of mutations of this gene in autism and epilepsy, an amazing group of motivated families formed an organization to help support and awareness for this gene mutation. This week’s podcast includes a message from one of the leaders of this foundation: FamileSCN2A who are dedicated to help their children with the knowledge about their child’s genetic makeup.