Some children show ASD symptoms within the first 12 months of life. In others, symptoms may not show up until 24 months or later. Some children with ASD gain new skills and meet developmental milestones, until around 18 to 24 months of age and then they stop gaining new skills, or they lose the skills they once had.

What is the number one cause of autism?

We know that theres no one cause of autism. Research suggests that autism develops from a combination of genetic and nongenetic, or environmental, influences. These influences appear to increase the risk that a child will develop autism.