In discussing the association of ASD with genetic changes, one should keep in mind the following:
- ASD is one of the most complex behavioral disorders and appears to have a strong genetic influence. However, it is unclear whether ASD can be explained by multigene interactions or by rare mutations. For each autistic individual, it is quite possible that mutations in more than one gene may be involved.
- There is accumulating evidence that ASD is caused by rare, inherited or spontaneous genetic mutations, such as copy number changes and single nucleotide alterations.
- FXS is the most commonly known single gene cause of ASD. Other genetic causes of ASD include deletions of chromosome 15q, tuberous sclerosis, and other rare genetic conditions.
- In many families, there appears to be a pattern of autism or related disabilities, further supporting the theory that the disorder has a genetic basis. While no one gene has been identified as causing autism, researchers are searching for irregular segments of the genetic code that children with autism may have inherited.
- Research identifying several genes that are related to ASD indicates that these genes may account for about 15% of the cases of ASD.
- The role of environmental factors in the development of autism is an important area of study. Although genetics may strongly influence the risk for developing ASD, genetics alone do not appear to account for all instances of autism.
