2Common Causes of Autism
There are many known underlying causes and risk factors of autism. These include;
Genetics
Scientists are studying twins to examine the influences of nature (genetics) and nutrition (environment) on given human quality. It is first important to understand that there are two types of twins. Identical twins share all or maximum of their genome and will share all of their environment if they grow up in the same household. Fraternal twins, like non-twin siblings, also share their entire environment but share only about half of their DNA.
Twin studies begin by identifying a particular population, say a city’s metropolitan area, and finding as many sets of twins as possible in the region that one or both of the twins are interested in – e.g., autism.
Researchers then look at the trait’s “concordance”— that is, the percentage probability that if one twin has autism, the other twin will have autism as well. If for identical twins, the concordance is higher than for fraternal twins, then we can say the difference is most probably due to the increased amount of genome shared by identical twins, and genetic influences on autism.
Recent twin studies have found that genetics play a significant role in the development of autism. The incidence of autism spectrum disorder is more than 90% in identical twins and 50% in fraternal or non-identical twins.
