In the August/September 2017 issue, we interview Christopher Jackson and his wife Veronica Vazquez-Jackson about their son CJ, who was diagnosed with severe autism when he was 2 years old. Now 12, he still has trouble regulating himself and continues with occupational therapy, but his parents are optimistic about his future. 

An array of genetic factors has been associated with autism spectrum disorder, as researchers apply recent advances in genetic analysis to zero in on the genes—and the complex interactions of those genes—that may be implicated in autism.

Studies of identical twins, who share 100 percent of their genetic makeup, show that they are more likely to share an ASD diagnosis than fraternal twins or siblings, who share roughly 50 percent of their genetic makeup. This suggests a strong link between genetic factors and ASD, and that a shared environment—in utero and in the home—may play less of a role. 

In addition, first-degree relatives—parents, siblings, and children—of people diagnosed with ASD show higher rates of the disorder than the general population. Interestingly, even those who are not diagnosed with the condition often demonstrate higher rates of ASD-like symptoms, such as social and language challenges and repetitive and restrictive behaviors.

Developmental genetic disorders such as Fragile X syndrome, tuberous sclerosis, and Down syndrome increase the likelihood of an ASD diagnosis.

Unlike simple hereditary traits such as fair skin or freckles, the disorder is thought to result from what is called complex genetics, in which a number of autism-susceptible genetic factors combine. This might explain why, for instance, some identical twins do not share a diagnosis, and why neurotypical children of parents with ASD may demonstrate some behaviors associated with autism.