The largest study on autism spectrum disorders (ASD) to date has identified 102 genes involved in the disorder, including 37 new genes that had not been recognised before. Published in Cell, the findings help researchers better understand the causes of the disorder, and could possible help in developing new drug therapies for children with severe impairments.

Autism spectrum disorder is a complex neurodevelopmental disorder that causes social, communication and behavioural challenges that exists on a spectrum. Not all children are affected equally, where some may have milder problems with communicating and socialising and others may be more profoundly affected with repetitive, obsessive behaviours. Some may have intellectual disabilities, and others could have average or above-average IQs.

Current therapies work for some individuals affected, but not for others. For those profoundly affected by the disorder, understanding the underlying causal genetics could help in developing precision treatments to target those pathways that may playing a role in developing the disorder.

It’s believed that genetics combined with environmental exposures can lead to ASD. Genetics has the most influence, with a recent study estimating that around 80% of ASD risk is caused by genetics. Using a large group can help to identify exactly which genes are at play, since not every person with ASD will have the same genes.

Before this study, 65 genes were identified in association with ASD. This new, largest exome sequencing study of ASD to date managed to find more due to the large number of participants. 35,584 individuals were involved, including nearly 12,000 individuals with ASD and the rest being parents, unaffected siblings or other individuals without ASD.

Some genes have high risk variations in developing ASD, but around 80% of people will not have these and instead will have small variations in multiple genes. Most of the high-risk genes include those involved in early brain development and have roles in regulating other gene activity or communication between brain cells. The identified risk genes showed that ASD isn’t only related to one major type of brain cell, as the genes are active in both “excitatory” and “inhibitory” neurons and are involved in many different pathways.

Future research with these findings could eventually lead to new therapies. New biological processes and pathways involved in ASD are always being identified and this research could lead to new potential targets for treatment and allow more personalised health care to be developed, helping those who are affected.