Causes for Autism

Children With Developmental Challenges 3(2+1)

Lesson 25 : Pervasive Developmental Disorders -Autism

Causes for Autism

The major causes for Autism in children include

  1. Genetic Susceptibility (Family Studies): Leo Kauner in 1943, while studying autism, noticed common traits among parents of autistic children:
    • Serious-minded
    • Perfectionist
    • Lack of interest in forming relationships

  2. Environmental Exposure: Speculated that neurotoxins interact with genes (at crucial time in development), but we are far from knowing exactly what neurotoxins come into play.


    • Up to 50 known agents produce developmental toxicity in humans E.g. alcohol, cocaine, organic mercury compounds, pharmaceuticals like thalidomide and valproic acid – antiseizure medication
    • Exposed pregnant mother to toxins Up to 1,000 agents produce developmental toxicity in animals.Probably more, with undetectable results to a lab experimenter. Lead, Mercury, pesticides, polychlorinated biphenyls (PCBs) shown to disturb the processes of neurogenesis and migration, as well as general immune functioning
    • Many chemicals in use for industrial or agricultural purposes have not been tested for neuro-developmental toxicity.

  3. Stages of Development
    • Neurodevelopment begins in the early embryonic stage and continues on through postnatal and even adolescence to a degree. Autistic children seem to be most prone during embryonic stages to the affects of neurotoxicity.
    • Processes of neuro-development:
      1. Neurogenesis
      2. Proliferation
      3. Migration
      4. Differentiation
      5. Synapse formation
      6. Myelination
    • Each process is susceptible to alteration via environmental agent interaction
      Day 20-25 of gestation, brain thought to be most susceptible to thalidomide (possible cause of ASD).
Last modified: Friday, 25 May 2012, 12:48 PM