Autism spectrum disorder encompasses many disorders with a range of symptoms and severity. The autism spectrum is a scale with classical autism being the most severe and Asperger syndrome, disintegrative disorder, and pervasive developmental disorder being more mild. Autism occurs equally among all ethnic and socioeconomic groups. However, boys are four times more …show more content…
Children often have trouble with socializing and communicating. The main symptom of autism is difficulty socializing. Beginning very early in life, babies may focus on only one item while excluding others or be unresponsive to social interaction. As children with autism get older they may have trouble understanding voice or facial expressions. This makes it difficult for them to know how to respond in social situations. They may avoid eye contact or not respond to their name. It is also difficult for them to understand how others are feeling. Autism may cause repetitive and self-harming behavior (“Autism Fact …show more content…
Researchers have found many genes that are associated with autism. Other researchers have found irregularities in certain parts of the brain. There are even others that have found abnormal serotonin levels in brains of those with autism. That research suggests that there may be a disruption in fetal brain development that is possibly caused by defects in genes that control brain growth. This could be caused by environmental factors that disrupt gene regulation. There does seem to be a genetic predisposition to autism based on family and twin studies. When one twin has autism there is a 90 percent chance the other twin has this disorder. In family studies when one sibling has autism there is a 1 in 20 chance that another sibling will have this disorder (“Autism Fact