Autism study identifies extensive gene pattern

A large, complex gene network in people with autism has been identified by researchers at the University of Oxford.

The study found that autism-related genes were linked in an extensive network, showing how different genes can affect interconnected biological pathways.

Medical Research Council scientists looked at certain genes related to autistic spectrum disorders (ASD) in 181 people. Those with ASD tend to have a different number of these genes than those without autism — this is known as a copy number variation (CNV).

The researchers found that 187 genes affected by CNVs were connected in a single, large network of interrelated biological processes. Almost half (45 percent) of those tested were shown to have one or more of these CNVs.

The study highlights how the different gene variations related to autism could result in the same group of conditions. Many of these genes encode proteins involved in signalling between nerve cells, suggesting that abnormal brain signalling causes some of the symptoms of ASD.

It is estimated around one percent of the population have an autistic spectrum disorder, which can affect behaviour, social interaction and communication. While many different genes have been associated with the condition, only one in five ASD cases has a known genetic cause.

Dr Caleb Webber, who led the study, said: 'Think of a pipe that carries water. At some points along the pipe there are genes that act as taps to let more water into the pipe. At other points genes act as holes to let some of the water out. We found that in individuals with autism the mutations in all these different types of genes act in the same way to affect water flow'.

'This indicates the 'tap' genes are duplicated in some individuals with autism which increases flow into the pipe, while in other individuals with autism the 'hole' genes are deleted which decreases the amount of water leaving the pipe. Both of these events cause the same thing - too much water flowing through the pipe'.

'Knowing not just which 'pipes' in the cell are affected in autism but also in what way they are affected helps us to know in which way we have to change the flow to restore the balance', Webber explained.