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.