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.
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.
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.
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.