Should all the symptoms of autism be present at the same age?

No: The synptoms are many and every child is uniquely different. Neonatal jaundice and/or "colic" and ear infections are potential warning symptoms of add. Adhd and autism. These early symptoms, if present, are the very first indications of "oxidative stress" and nutrient supplements should be started then, even if it is only a potential indication of worse thngs to come.

Autistic Spectrum: Disorder begins before age, but many toddlers have deficits in social communication ; social reciprocity with less obvious stereotypies (non-functional, repetitive movements) ; they're too young to have narrow, restricted ateas of interest. Careful observation reveals repetitive, sensorimotor acts like banging ; dropping toys or lining up objects. The diagnosis requires deficits in all 3 areas.