No babbling by 12 months.

No pointing or gesturing by 12 months.

No single words by 16 months.

No two-word phrases by 24 months.

Loss of previously acquired developmental skills, especially language.

Your child does not respond to his/her name.

Lack of pretend, imitative, and functional play appropriate to your child’s developmental age.

Unable to develop peer relationships appropriate for your child’s developmental age.

Your child does not imitate others’ behaviors.

Your child is rigid in routines or has difficult transitions.

Your child engages in repetitive behavior.

Your child has unusual or exaggerated responses to sensory stimuli (for example, covering his/her ears or becoming upset with loud noises, cannot have tags in clothing, will avoid foods of certain textures).

Your child has trouble relating to others or does not have an interest in other people at all.

Your child avoids eye contact.

Your child wants to be alone.

Your child appears to be unaware when others talk to him/her but responds to other sounds.

Your child repeats or echoes words or phrases said to them or repeat words or phrases in place of normal language.

Any family, physician or teacher have concerns about your child’s development or behavior.