Son was just diagnosed with autism. 2 of his cousins also have (from 2 different siblings of mine). what are the chances this is genetic?

Likely: There is no known single cause for autism, but it is generally accepted that it is caused by abnormalities in brain structure or function. Brain scans show differences in the shape and structure of the brain in children with autism versus in neurotypical children. Genetics appear to play a strong role in autism but no one gene has been identified yet. .

Current standard of : practice is to obtain a Chromosomal Microarray and a DNA Probe for Fragile X in all children with Developmental Delays &/or Autistic Spectrum Disorder. These require a blood sample or the kids' pediatricians can contact Lineagen Lab ( in which I have no financial interest) at (801) 931-6224 to obtain a kit for buccal swab testing. A clinical genetics evaluation would be needed for positive results.