Big data reveals more suspect autism genes

Researchers have isolated 18 new genes believed to increase risk for Autism Spectrum Disorder (ASD), a finding that may pave the way for earlier diagnosis and possible future drug treatments for the disorder.

The study, published this week in Nature Neuroscience, used a technique called whole genome sequencing (WGS) to map the genomes of 5193 people with ASD.

WGS goes beyond traditional analyses that look at the roughly 1% of DNA that makes up our genes to take in the remaining “noncoding” or “junk” DNA once thought to have little biological function.

The study, led by Ryan Yuen of the Hospital for Sick Children in Toronto, Canada, used a cloud-based “big data” approach to link genetic variations with participants’ clinical data.

Researchers identified 18 genes that increased susceptibility to ASD, noting people with mutations in those genes had reduced “adaptive functioning”, including the ability to communicate and socialise.

“Detection of the mutation would lead to prioritisation of these individuals for comprehensive clinical assessment and referral for earlier intervention and could end long-sought questions of causation,” the authors write.

But the study also found increased variations in the noncoding DNA of people with ASD, including so-called “copy number variations” where stretches of DNA are repeated. The finding highlights the promise of big data to link fine-grained genetic changes with real world illness, something the emerging discipline of precision medicine will harness to better target treatments.

Commenting on the study, Dr Jake Gratten from the Institute for Molecular Bioscience at the University of Queensland said, “whole genome sequencing holds real promise for understanding the genetics of ASD, but establishing the role of noncoding variation in the disorder is an enormous challenge.”

“This study is a good first step but we’re not there yet – much larger studies will be needed,” he said. ASD affects around 1% of the population, and is characterised by impaired social and emotional communication, something poignantly depicted by John Elder Robeson in his 2016 memoir Switched On.

But the study findings went beyond autism, isolating ASD-linked genetic changes that increase risk for heart problems and diabetes, raising the possibility of preventative screening for participants and relatives.

The authors note that 80% of the 61 ASD-risk genes already discovered by the project, a collaboration between advocacy group Autism Speaks and Verily Life Sciences, and known as MSSNG, are potential research targets for new drug treatments.

But the uncomfortable nexus between scientific advances and public policy is also highlighted this week in an editorial in the New England Journal of Medicine. Health policy researchers David Mandell and Colleen Barry argue that planned Trump administration rollbacks threaten services to people with autism.

Any repeal of the Affordable Care Act (“Obamacare”) they write, could include cuts to the public insurer Medicaid and subsequent limits on physical, occupational and language therapy for up to 250,000 children with autism.

The authors also warn that comments made by US Attorney General Jeff Sessions bode ill for the Individuals with Disabilities Education Act (IDEA), legislation that guarantees free education for children with disabilities such as autism. Sessions has reportedly said the laws “may be the single most irritating problem for teachers throughout America today.”

The authors also voice concern the Trump administration’s embrace of debunked links between vaccination and autism are a major distraction from these “growing threats to essential policies that support the health and well-being of people with autism or other disabilities”.

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