Identifying subtypes for autism and narrowing down the heterogeneity of symptoms has been considered the holy grail of autism research. If one person with autism is not like another person with autism, can they at least be put into groups to speed up studies into causes, intervention and services? And how? This podcast explains two different studies that used the same statistical method but different children with autism to identify different groups. One of the things that helped define these groups was verbal ability and IQ. For the first time, comorbid symptoms like medical issues and psychiatric diagnoses are being taken into account. Already, this approach is helping scientists better understand why fever improves symptoms in some people with autism.
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.
This week I am in Minneapolis at an incredibly important meeting of Medical Examiners to pitch them the importance of collecting brain tissue for Autism BrainNet. While I was here I noticed a new study on the blogs that is important for families to hear about. It focused on a known environmental exposure in established genetic groups. The authors of the study, led by Dr. Sara Webb at University of Washington, showed that an environmental exposure can modify symptoms in genetically susceptible narrow subgroups. This is the sort of research that will better describe how environmental exposures are affecting autism risk. Thank you to Dr. Sara Webb for your perspectives and interpretation of the data!