While the causes of autism spectrum disorders (ASDs) remain unknown, experts believe they have pinpointed factors that may place people more at risk of developing autism.
Genetics can place an individual at risk for developing some form of autism. According to the Autism Society, if a person has a brother, sister, twin, or parent with an ASD, that person is more likely to also have an ASD.
Some medical conditions have been connected to a higher risk of having autism. These include genetic disorders such as fragile X syndrome and tuberous sclerosis. Though the link between tuberous sclerosis and ASD is unclear, studies have shown that ASD rates are much higher among children with tuberous sclerosis than those who do not have the disease.
Some key risk-related statistics provided by the Centers for Disease Control and Prevention (CDC) include:
- Most scientists agree that genes are one of the risk factors that can make a person more likely to develop ASD.
- Children who have a sibling with ASD are at a higher risk of also having ASD.
- When taken during pregnancy, the prescription drugs valproic acid and thalidomide have been linked with a higher risk of ASD.
- There is some evidence that the critical period for developing ASD occurs before, during, and immediately after birth.
- Children born to older parents are at greater risk for having ASD.
Exposure to Certain Drugs
The CDC states that some drugs, like thalidomide and valproic acid, have also been implicated in causing higher risk of ASDs if they are taken while a woman is pregnant.
Exposure to heavy metals and other toxins in the environment is also suspected of increasing the risk of ASDs.