Here’s a game of join the dots. Hundreds of genes have been linked to autism, but to understand the roles they play – and the ones most likely to eventually lead to treatment – we need to work out how they are connected to one another.
Now Caleb Webber at the University of Oxford and his colleagues have done that, creating the largest interacting network yet of genes linked to autism.
The team looked at the DNA of 181 individuals with autism and found they often had either more or fewer copies of certain genes known to be important for the transmission of brain signals, a system thought to go awry with autism.
By feeding these genes into a computer model and tracing their interactions, they were able to build a web-like network, with genes in the centre having many connections and those at the edge just a few.
They found that many of the genes identified in the 181 people were connected to others that had previously been linked to autism.
By turning certain genes on or off in the model, the team found that extra or missing copies of genes in the centre of the network were much more likely to disrupt brain signalling – and therefore be influential in autism – than those on the edge.
In some cases, a single central gene had the same impact as a whole group of peripheral genes. The concept is similar to what happens in road networks, says Webber. Disrupting one main road can have the same effect as disrupting many back roads.
Peter White at the Children’s Hospital of Philadelphia welcomes a study that does not assume all genes play an equal role. But it also shows the complexity of autism genetics, he says. “In my view, this type of approach will increasingly be needed to explain autism spectrum disorders.”
Journal reference: PLoS Genetics, doi.org/ms4
(Article written by Douglas Heaven and first appeared in New Scientist Magazine).