Contrary to what is currently thought, environmental factors may play a larger role than shared genes in the development of autism, the study suggests. Antidepressants during pregnancy may be an example of an environmental trigger.
Other influences “environmental” include everything that is not in the genetic code. Research has suggested that a variety of possible factors, including maternal or paternal age advanced, the technology of assisted reproduction and artificial insemination, the mother’s infections during pregnancy, multiple births, prematurity, low birth weight and complications of childbirth may be among the environmental factors.
In the first study, researchers at Stanford University identified 192 twin pairs from a California state record. At least one twin had been diagnosed with an autism spectrum disorder, which researchers confirmed by tests and tests for each child.
The study included 54 pairs of identical twins (which means they share all genes) and 138 pairs of fraternal twins (who share half the genes).
It is not surprising that both identical twins were more likely to have autism and genes shared by all, and knew that genetics has to do with the development of autism. However, if a disorder was due entirely to genetics, both siblings in each pair of identical twins suffer it, which does not occur in autism.