Positional and Functional Candidate Genes

Candidate genes are suspected to be directly linked to autism and related pervasive developmental disorders. The researchers work toward either ruling out the candidate gene or finding the specific link between the gene and autism.

According th the website Exploring Autism, candidate genes can be separated into two major groups: positional and functional.

• Positional candidate genes are suspect because they are located in a certain area of a chromosome that is thought to be linked to autistic disorder.
• Functional candidate genes are suspect because researchers have made other discoveries that trace back to the specific function of those genes. If a certain gene makes a chemical that is either lacking or in excess in cases of autism then that gene is considered a functional candidate gene.