Autism research has hit a breakthrough point equivalent to the one that revolutionised the understanding and treatment of cancer 30 years ago, it has been claimed.
Three major studies have for the first time pinpointed genetic mechanisms underlying autistic disorders, including ones which are relatively common.
Scientists believe the findings could mark as big a transformation in tackling autism as occurred when researchers began to unravel the genetic causes of cancer.
Autism covers a group of conditions known as autism spectrum disorders (ASDs) which affect about one in 150 mostly male children.
They are marked by an impaired ability to communicate and interact socially, narrowly focused attention, and repetitive behaviour.
A complex genetic jigsaw is believed to underpin autism, but identifying the pieces has proved difficult.
Although a number of genetic variants have previously been implicated in ASDs, the connections have not been clear.
The new research, which involved screening the DNA of many thousands of volunteers, may at last have lifted the lid on the causes of autism, scientists believe.
It suggests that proteins called cell adhesion molecules, which play a vital role in shaping brain “wiring” and the way nerve cells communicate, play a key role in autism disorders.
New treatments could now be developed that target these proteins or the genes that provide the instructions for making them.
Two of the new studies were American-led and reported yesterday in an early online edition of the journal Nature. The third was conducted by British scientists at Oxford University and appears in the journal Molecular Psychiatry.
The largest investigation, conducted in the US, involved analysing the DNA of almost 13,000 people including many from families affected by autism.
Comparing the entire genetic code of these different individuals enabled scientists to focus on a “hotspot” on chromosome five — one of the coiled up “packets” of DNA within the nuclei of cells that contain the genes.
Children with autism were significantly more likely than their healthy counterparts to have variations in the genetic code in this chromosomal region. The hotspot is located between two genes, CDH9 and CDH10, that code for neuronal cell adhesion molecules.
PA