The Transcription Factor Song

Very rarely are scientists able to look at single genes within the brains of people across neuropsychiatric disorders and understand how the genes in each of these cells influence expression of proteins and interactions of different cells with each other. Recently, a collaboration called PsychENCODE released a series of papers that investigated what genes are expressed in what cells in autism in different situations, how cells that communicate interact with more support or glial cells, and what mechanisms are in place to identify ways in which the broad environment (chemicals, contextual factors, illness) may influence gene expression leading to disorders like autism, schizophrenia and bipolar disorder. This podcast summarizes these papers as they are related to autism – ore at least tries to.

https://www.psychencode.org/phase-ii

Little Brains Answer Big Questions

This week we talk to Sergiu Pasca from Stanford University. He has revolutionized the field of understanding the field of brain development in neurodevelopmental disorders and just published a new study which examined the genetic influence of brain assembly. The way he does this is quite remarkable. His lab uses assembloids, which are many many many stem cells which form into a tiny brain. He explains what an interneuron is, why it is important for brain function, and how genetics can influence how these neurons work. This way the development of the brain from the first cell can be tracked and even manipulated to understand what happens in autism, and what therapies might be the most helpful to target these interneurons. Thank you Dr. Pasca.

Open access! https://pubmed.ncbi.nlm.nih.gov/37758944/

Environmental factors as both causes and interventions?

Environmental exposures, including toxic chemicals, can contribute to the causes of ASD. But how do other environmental factors, like behavioral supports, work in the brain to improve behaviors associated with ASD? For this, you need a broad interpretation of the term “environmental” and an animal model so you can see the mechanism involved. Studies show while environmental factors can contribute, they can also provide modifications in cellular and molecular function which support learning and improved developmental trajectory. Finally, on a different topic, are autistic adults more likely to be involved in a crime compared to other groups? No, they are not, but there are factors which affect the risk of being involved with the criminal justice system, at least in the UK. Read more in the studies below.

https://pubmed.ncbi.nlm.nih.gov/34972219/

https://pubmed.ncbi.nlm.nih.gov/35259351/

https://pubmed.ncbi.nlm.nih.gov/35261275/

Genes genes all in an order, the ones you have, the greater risk of disorder

This week, a special focus on genetics:  what type, where do they come from, what do these genes do and how do they influence risk of a wide array of psychiatric issues including autism.  The results come from the largest study to date of people with autism as well as those with ADHD, bipolar disorder and schizophrenia.  It’s also the largest study of the Female Protective Effect so far.  Even if genetics does not explain everything about ASD, genetics is important and you deserve to know why.  Below is a graphical abstract of what they found:

 

 

https://www.cell.com/action/showPdf?pii=S0092-8674%2819%2931398-4

https://www.ncbi.nlm.nih.gov/pubmed/31835028

 

What sperm tells scientists about the origins of ASD

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.

 

Reusing and recycling autism data from brain tissue

In a new study in animal models, researchers demonstrate how genetic variability in key risk genes leads to different brain development patterns.  Studying the brains of people with autism is challenging, since there are fewer resources to study.  However, scientists get creative and collaborative and re-analyze datasets previously published to look at different research questions.  That’s what happened this week in a collaboration between Brown University and UCLA, showing that as the activity of genes which controls the synapse goes down, so do genes affecting mitochondrial function.  Another brain tissue study showed that the stress of the endoplasmic reticulum, which is associated with the mitochondria, may be elevated.  Not all research data can be re-purposed again, which is why it is so important to study the brains of people with autism.  If you would like to learn more, go to www.takesbrains.org/signup

 

https://www.ncbi.nlm.nih.gov/pubmed/29859039

https://www.ncbi.nlm.nih.gov/pubmed/29761862

https://www.ncbi.nlm.nih.gov/pubmed/29901787

https://www.ncbi.nlm.nih.gov/pubmed/29926239

Chromosome 15-apallooza

One of areas of genetic interest of autism is a region of chromosome 15.  Only about 3% of people with autism have the mutation, but 80% of those with the mutation have autism.  It is so important that people with duplications of this area have formed their own advocacy group called the Dup15 Alliance.  I was honored to attend their family an scientific meeting and give a summary of what scientists have learned about autism through studying this chromosome, how kids with this mutation and autism are similar and different from those with autism but not the mutation, how the families are managing life threatening seizures, what the gene does, what the brains look like, and how mutations of this chromosome do in fact interact with the environment.  Thank you to the scientists who study this area and the very brave, selfless and amazing parents who I talked to.

Oops the media did it again…

Last week CNN.com reported on a study that showed slight improvement of autism symptoms in children that received a single infusion of their own umbilical cord blood.  While the study was interesting, the authors were the first to acknowledge the limitations, however, this did not stop the media from misrepresenting the results.  Details are explained in this podcast.  In addition, a big win this week for precision or personalized medicine:  different symptoms and different genetic mutations are linked to different outcomes from different anti-seizure medications.

Exploiting genetics to understand environmental risks for autism

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.