The precise etiology of Asperger's syndrome is uncertain. While it is mostly inherited, the underlying genetics have yet to be discovered definitively. Environmental variables are thought to play a role as well. The symptoms generally appear by age four or five. Some researchers believe that many people are born with Asperger's, but that others develop it due to environmental factors. Those who are diagnosed later in life may not meet all of the criteria required for an official diagnosis. There is some evidence to support this idea. People who were born with Asperger's tend to share certain genetic markers. Also, children who are raised by parents who have the condition are more likely to be diagnosed with it themselves. This suggests that something in their environment must have made the difference. The cause of Asperger's is probably a combination of genetic and environmental factors. Some people are just born with it while others develop it over time. Children who are born with the condition tend to have some common genetic markers. If you are concerned that your child might have Asperger's, talk to his doctor. There are treatments available that can help make him able to function better at school and with friends.