Autism spectrum disorder (ASD) is subject to much misinterpretation and mystery. While it affects roughly 700,000 people in the UK alone - more than 1 in 100 - the exact cause is unknown. Scientists suspect ASD is a result of a combination and environmental and genetic factors and now, the world's largest autism database, Autism Speaks' MSSNG Project, has highlighted an additional 18 gene variations linked to its development. Read more: What is autism spectrum disorder? WIRED explains
Published in the journal Nature Neuroscience, the report finds that many of the 18 newly-identified autism genes are related to a small subset of pathways in the brain that affect how cells 'talk' to each other. The report also establishes a number of so-called 'copy number variations' and abnormalities that are particularly common in the genomes of people affected by autism. These copy variations can be found in areas of the genome once considered to be 'junk DNA'. These areas help to control when and where our genes switch on and off and appear to be crucial to brain development and function.
The omitted letters in the MSSNG Project's name stand for the gaps in our understanding of ASD. Since 2014, the collaborative project between Google and Autism Speaks has sequenced the DNA of more than 10,000 families affected by ASD. The goal is to identify subtypes of autism to one day create personalised treatments.
Traditional methods of genetic analysis for autism have focused on single variations in 1 per cent of DNA. MSSNG allows for analysis of 3 billion DNA base pairs within a person's genome.
The study's senior investigator, Stephen Scherer, Ph.D., said "the depth of the MSSNG database allowed us to identify resilient individuals who carry autism-associated gene variations without developing autism. We believe that this, too, is an important part of the neurodiversity story."
Studying the genetic sequences of different family members is an important part of appreciating the spectrum variations of autism. In one family member, the condition can present itself in severe ways while for another it may be unclear the individual is autistic at all. These variations not only make diagnosis difficult, they also leave worrisome blind spots in our understanding of how genetic variations present themselves within family dynamics.
A Newsweek report on the disorder recently explored the difficulty of treating the neuro-developmental condition, as "no single feature is present in all — or even a majority of — people with autism."
All data derived from MSSNG's project is available in an open-sourced Google cloud platform. More than 90 partners at academic and medical institutions are using the database, and healthcare professionals are encouraged to join MSSNG. In the next few weeks, the total number of sequenced autism genes collected by MSSNG is expected to rise to 7,000.
The importance of genetic sequencing for autism cannot be understated. Understanding the biological factors that contribute to subsets of the condition can lead to individual treatments, as is needed with a spectrum disorder. Understanding genetic variations can then, in turn, lead to improved understanding of future treatments.
Mathew Pletcher, Ph.D., Autism Speaks' vice president for genomic discovery, said that "in all, 80 per cent of the 61 gene variations discovered through MSSNG affect biochemical pathways that have clear potential as targets for future medicines."