What Causes Autism?

[Lawrence Sheen]

As the public has become increasingly aware of the incidences of ASDs,
many parents are left wondering what causes this disorder.
No Single Cause
Researchers still do not know a lot about what causes ASDs, although
they have learned a great deal about the symptoms these disorders
cause. While the Centers for Disease Control and Prevention reports
that, for most affected people, there is no single known cause,
genetics and the environment are contributing factors.
Genetics The CDC reports that, among identical twins, if one twin has
autism, the other will be affected around 75% of the time. In non-
identical twins, the rate at which the other child is affected drops
to 3%. Siblings of a child with ASD have a 2% to 8% chance of being
affected by an ASD. Because there appears to be a pattern of ASDs in
many families, there is support for the genetic basis of this
disorder. No one gene has been identified as a cause, however.
Researchers are working on isolating irregular segments of genetic
code that may be present in children with autism. Research indicates
that some children are born with a susceptibility to autism, but so
far no one "trigger" for development has been identified.
ASDs do tend to appear more frequently in people with certain other
medical conditions like untreated phenylketonuria, fragile X syndrome,
congenital rubella syndrome, and tuberous sclerosis. Environmental
Factors
According to The Autism Society, research indicates that environmental
toxins are contributing to the rise in ASD occurrances. Heavy metals
such as mercury are more prevalent in our environment now than they
have been in the past, and build-up of these toxins can lead to
nervous system and brain damage and developmental delays.
While there are theories that vaccines, particularly those with
mercury content, cause autism, research has not made a conclusive
connection between vaccines and ASDs. What Else Parents Should Know
Autism is a treatable disorder, but it is a complex one, both in terms
of causes and manifestations of the disorder. Be sure that you check
with your pediatrician at your child's regular visits to determine
that he is meeting developmental milestones at the appropriate times.
If you have a family history of autism, your child may need to be
monitored more closely.