Aetiology of autism: findings and questions

J Intellect Disabil Res. 2005 Apr;49(Pt 4):231-8. doi: 10.1111/j.1365-2788.2005.00676.x.


Background: Although there is good evidence that autism is a multifactorial disorder, an adequate understanding of the genetic and non-genetic causes has yet to be achieved.

Methods: Empirical research findings and conceptual reviews are reviewed with respect to evidence on possible causal influences.

Results: Much the strongest evidence concerns the importance of susceptibility genes, but such genes have yet to be identified. Specific somatic conditions (such as tuberous sclerosis and the fragile X anomaly) account for a small proportion of cases. Over recent decades there has been a major rise in the rate of diagnosed autism. The main explanation for this rise is to be found in better ascertainment and a broadening of the diagnostic concept. Nevertheless, some degree of true rise cannot be firmly excluded. However, the epidemiological evidence on the main hypothesized environmental explanation, namely the measles-mumps-rubella vaccine, is consistently negative.

Conclusion: Progress on the elucidation of the causes of autism will be crucially dependent on the combination of epidemiology with more basic science laboratory studies.

MeSH terms

  • Anti-Infective Agents, Local / adverse effects
  • Autistic Disorder / etiology*
  • Autistic Disorder / genetics
  • Child
  • Chromosome Aberrations
  • Chromosomes, Human, X / genetics
  • Female
  • Fetal Diseases / microbiology
  • Genetic Predisposition to Disease
  • Humans
  • Measles-Mumps-Rubella Vaccine / adverse effects
  • Pregnancy
  • Pregnancy Complications
  • Prenatal Exposure Delayed Effects
  • Thimerosal / adverse effects


  • Anti-Infective Agents, Local
  • Measles-Mumps-Rubella Vaccine
  • Thimerosal