Data from 50 laboratories around the world has found that rare mutations in dozens of genes may be responsible for 30% or more cases of autism.
The mutations affect communication networks and vital biological mechanisms which change how or whether other genes are activated.
One hundred genes were identified by researchers, of which 60 were found to have a high chance of contributing to the risk of autism.
The majority of the mutations identified do not come from the parents but arise spontaneously in the sperm or egg just before conception.
The results come from two studies: one of over 2,500 families where a single child has autism but neither parent nor siblings have the condition and another using data through the Autism Sequencing Consortium (Iossifov et al., 2014; Rebeis et al., 2014).
Stephan Sanders, one of the study’s first authors said:
“Before these studies, only 11 autism genes had been identified with high confidence, and we have now more than quadrupled that number.”
Sanders estimates that this is just the tip of the iceberg — as many as 1,000 genes could ultimately be linked to the risk of a child developing autism.
While this might seem like bad news, Dr. Matthew W. State, a study co-author, said the outlook is not that poor:
“There has been a lot of concern that 1,000 genes means 1,000 different treatments, but I think the news is much brighter than that.
There is already strong evidence that these mutations converge on a much smaller number key biological functions.
We now need to focus on these points of convergence to begin to develop novel treatments.”
Dr. State continued:
“These genes carry really large effects.
That we now have a bounty of dozens of genes, and a clear path forward to find perhaps hundreds more, provides an incredible foundation for understanding the biology of autism and finding new treatments.”
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Image credit: Jose-Luis Olivares/MIT