Brief Report: Relationship Between Non-verbal IQ and Gender in Autism

  • Ryan Banach
  • Ann Thompson
  • Peter Szatmari
  • Jeremy Goldberg
  • Lawrence Tuff
  • Lonnie Zwaigenbaum
  • William Mahoney
Brief Report


It has been proposed that females at risk for autism are protected in some way, so that only those with the greatest genetic liability are affected. Consequently, affected male siblings of females with autism should be more impaired than affected male siblings of male probands. One hundred and ninety-four (194) families with a single child with autism (simplex, SPX) and 154 families with more than one child with autism (multiplex, MPX) were examined on measures of severity, including non-verbal IQ. Among SPX families, girls had lower IQ than boys, but no such differences were seen among MPX families. Similarly, the affected brothers of girls with autism were no different from affected brothers of male probands. These data suggest that MPX and SPX families differ with respect to the relationship between gender and IQ.


Autism IQ Gender Genetic 


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Ryan Banach
    • 1
  • Ann Thompson
    • 2
  • Peter Szatmari
    • 2
    • 5
  • Jeremy Goldberg
    • 2
  • Lawrence Tuff
    • 2
  • Lonnie Zwaigenbaum
    • 3
  • William Mahoney
    • 4
  1. 1.Department of Family MedicineMcMaster UniversityHamiltonCanada
  2. 2.Department of Psychiatry and Behavioural NeurosciencesMcMaster UniversityHamiltonCanada
  3. 3.Department of PediatricsUniversity of AlbertaEdmontonCanada
  4. 4.Department of PediatricsMcMaster UniversityHamiltonCanada
  5. 5.Offord Centre for Child StudiesMcMaster UniversityHamiltonCanada

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