Genetic Causes of Autism
There have been many speculations regarding the genetic causes of autism but a five-year long study by geneticist Stephen Scherer of the University of Toronto and the Hospital for Sick Children in Toronto has come out with some concrete results. The study was entitled 'Mapping autism risk loci using genetic linkage and chromosonal rearrangements' and presents evidence for the gentic causes of autism. The study says that autism has “numerous genetic origins rather than a single or a few primary causes.” The study is based on an analysis of DNA samples from 1,168 families which had two or more autistic children.
Genetic Causes of Autism
The study, published in 'Nature Genetics' magazine holds the neurexin-neuroligin link as “fundamentally important for glutamatergic synaptogenesis and thereby points to glutamate-related genes as promising candidates for contributing to ASDs.” The chemical, glutamate, is a neurotransmitter whihc helps memory formation and processing of information by the brain. A flaw in the genes responsible for the formation and working of this chemical may be one of the major genetic causes of autism.
Another support for the genetic causes of autism comes from a study involving identical twins whihc was conducted as the MRC Child Psychiatry Unit at the Institute of Psychiatry in London. The study found that there was a 60% chance of one of a pair of identical twins developing autism if the other one already had the disorder. What supports the claim of genetic causes of autism is the fact that the chances of the second twin developing autism when the first one had it, in the case of non-identical twins was not significantly higher.
A word of caution is necessary, though. Environmental factors are thought to play a role in developing autism too since not all identical twins develop autism if one has it. In summary, more research is required before it can be said that the genetic causes of autism overshadow the environmental factors.