(HealthDay News) -- Symptoms of autism can be difficult to recognize in very young children, especially in mild cases or in instances when a child has other mental or physical conditions.

The U.S. National Institute of Neurological Disorders and Stroke mentions these possible early symptoms of autism:

• No pointing or babbling by age 1, or the absence of saying single words by age 16 months.
• No response to calling the child's name.
• Lack of early social or language skills.
• No eye contact with others.
• Obsessive organizing or lining up of objects.
• Not smiling.