Recent research has found that tiny changes in a common gene have a stong impact on the likelihood of developing autism and related conditions. The changes in the genes affect the way connections between brain cells are formed and maintained. Other genetic variants have been found in the past but they are relatively rare. In contrast if the newly discovered variant were corrected, cases of autism would be reduced by 15%.
Dr. Raynard King, of the US National Institute of Health, which funded the research, said “These findings establish that genetic factors play a strong role in autism spectrum disorder (ASD)”. It is hoped that the research will lead to better strategies for diagnosing and treating children with autism.
Two specific genes were pinpointed, which are found on chromosome 5. These control production of proteins which help cells to stick to each other and thus make nervous connections. One variant, linked to a gene called CDH10. was found to be present in over 65% of cases of autism.
Research also found that a group of about 30 other genes were also less strongly linked to ASD. These produce proteins which enable brain cells to migrate to correct places and to connect to neighbouring cells.
Commenting on these findings the lead researcher, Dr. Hakon Hakonarson, from the University of Pennsylvania, noted that “There are going to be many genes involved in causing autism”. He added that it is believed that each gene contributes a small amount of risk which then interacts with both other genes and environmental factors to trigger onset.
Professor Simon Baron-Cohen from the University of Cambridge said that 133 genes had now been identified and linked to autism and that more work was need to piece together the puzzle. He commented “The science of autism is accelerating in promising ways”.
The National Autistic Society also commented on the research findings. They said the exact causes of autism were unknown, although evidence suggests that genetic factors are responsible for some forms of autism. This is compounded by interaction of both the genes and environmental factors.
To read more about the research click on to the link below:
http://news.bbc.co.uk/1/hi/health/8020837.stm
Jane Gregory
Specialist Speech and Language Therapist
May 2009
