Risk Factors for Autism
Autism is a complex disorder that is not completely understood. There are many areas of active research trying to discover what factors may put a child at risk for autism.
The main risk factor for autism is heredity. Autism spectrum disorders are thought to be caused by multiple genes.
Autism is a multifactorial condition, which means that more than one thing is responsible, probably many different things. Autism is also a spectrum disorder, meaning that there is wide variation in how severely people with autism are affected. The term autism spectrum disorder is often used, or ASD.
The main risk factor for autism is heredity. Autism spectrum disorders are thought to be caused by multiple genes. Research is ongoing, looking for the genes. Because multiple genes are involved, and because other factors may play a role, family members with the same genes do not show the exact same symptoms. With autism, it may “run in the family,” but every case will be different, and many people will not be affected.
If one child in a family has a condition anywhere on the autism spectrum, the chances of a sibling having autism are approximately 5 to 6%. If two children have autism, the risk for another child is even higher. If one of two identical twins has ASD, the other twin has an 80 to 90% of developing autism. Male children are much more likely to be affected than female children by a ratio of at least 4 to 1.