The causes of ASD are not known. Research suggests that both genes and environment play important roles. ASD occurs in people of all races, nations and socioeconomic statuses.
Researchers have identified a number of genes associated with the disorder, and studies of people with ASD have found irregularities in several regions of the brain. Other studies have suggested that abnormal levels of serotonin or other neurotransmitters in the brain are associated with ASD.
All of these findings are preliminary and require further study.
Parental practices do not cause ASD. Statistics-wise, boys are much more likely to be diagnosed with ASD than girls.
