what makes a child autistic

Autism spectrum disorder (ASD) is a developmental disability caused by differences in the brain. The exact cause of ASD is not known, but scientists believe it is caused by both genetic and environmental factors. Some children with ASD have a known genetic difference, such as a mutation in a specific gene. Changes in certain genes increase the risk that a child will develop autism, and if a parent carries one or more of these gene changes, they may get passed to a child (even if the parent does not have autism) . Other times, these genetic changes arise spontaneously in an early embryo or the sperm and/or egg that combine to create the embryo. However, the majority of these gene changes do not cause autism by themselves. Environmental factors, such as pregnancy and birth complications, may also increase the risk of ASD. Vaccines do not cause autism. Signs of autism in children include lack of eye contact, no response to name being called, lack of babbling between 6-12 months, lack of pointing for communication by 12 months, not saying any words by 18 months, and loss of language at any age.