how does a kid get autism

Note: This article is part of a series on the history of autism treatment.

The topic of how a child develops Autism can be highly controversial. There are many different opinions in regards to how Autism is developed. It is essential to navigate the information based on the scientific evidence that is available.


Based on a study that was completed in 1977 on identical twins, a genetic link was found to contribute to Autism. The study found that when a one twin has the characteristics of Autism, the other twin is 80% likely to have the condition as well. It was also discovered through this study that there is a 40% likelihood for fraternal twins. These findings have lead researchers to believe that further research into the genetics of Autism is essential. Mutations occur during cell development and while most mutations that occur genetically are harmless, there are some mutations that can lead to symptoms of Autism. However, genetics alone cannot give us the answer to how Autism is developed.

Environmental Factors

Environmental factors do play a role in the diagnosis of Autism. Defining those factors and then studying them can present a challenge. One challenge can be equating environmental factors and vaccines. Another challenge can be assessing the many other factors occurring in the environment. Also, these factors cannot be determined through the same method as genetic testing. There must be other ways of testing the risks of environmental factors.

Maternal Immune Response

A study completed in 2015 suggests a link between viral infections during pregnancy and autism related symptoms. The study suggests that having a serious viral infection during pregnancy raises the risk for having a child with Autism. However, a small portion of women did not have children with Autism, despite having a serious viral infection. This suggests that there is a possible genetic component as well. Another study completed in Sweden on 2 million participants discovered that the likelihood of having a child with Autism after a serious viral infection increases by 37%. A Danish study of over 100,000 participants discovered that having a week long fever can triple the odds. This link is called the Maternal Immune Response.

Other Environmental Concerns

In the past decade, there have been many other studies designed to find a link between environment and Autism. Folic Acid, antidepressants, prematurity, parental age, parental weight, air pollutants, pesticides and many more factors have been indicated to possibly contribute to Autism. The consensus remains intact that the combination of genetics and environmental factors contribute to the Autism related symptoms. The environmental link has not been studied as extensively as genetics has been studied. This leaves room to learn much more about the environment and its effects on the development of Autism.


Researchers believe that progress has been hampered by the theory that childhood vaccines cause Autism. This is a theory that the scientific community thoroughly discredits. Since 2003, there have been 9 studies completed regarding vaccines and Autism. According to the reports from these studies, no links have been found to connect vaccines and Autism. The concern remains that the public’s view of vaccines has caused the scientific community to be skeptical regarding environmental factors. Those in the Autism research field have come against obstacles in discovering new risk factors when the public equates vaccines and environment.

Air Pollution

Air pollution has been a concern for a variety of health conditions. It has also been questioned as an environmental factor in the development of Autism. More than a half dozen studies completed in the US have found that exposure to air pollution in utero or in the first years of life raises a child’s risk for Autism. These findings were found in various areas of the US, not just one specific region with specific conditions. One study indicated that the risk increases if exposure occurs during the third trimester of pregnancy. However, other similar studies completed in Europe did not find a link between air pollution and Autism. Due to this discrepancy, a more consistent analysis procedure is needed in other countries and in the US. According to the information collected in current studies, there is not a definitive link between air pollution and Autism.

Coming to a Conclusion

When attempting to find a genetic link, a blood test is all that is required. However, there is still no ‘Autism gene’. As we have discussed, finding an environmental link to Autism is more complicated. The testing must be completed on a variety of factors to determine a causal link. The studies that would need to be done are time and cost intensive. The factors that have the most weight are the maternal immune response and air pollution, even though those links are not definitive. The various factors that could be linked with genetics still require more research. This research can aid the in merging of genetic and environmental factors and may lead to new hypotheses and finding answers with more clarity in the future of Autism research.