Causes Of Autistic Spectrum Disorders Research Articles

Looking beyond risk: A study of lay epidemiology of childhood disorders

Davison, Frankel, and Davey Smith (1989) conceptualised lay epidemiology as the process of interpreting health risks through considering non-traditional sources of information drawn from personal networks and from the public arena. We analysed 100 unsolicited letters received by professional epidemiologists studying the causes of autistic spectrum disorders (ASD). The correspondents sourced their ideas from an interaction between personal, social, media, and scientific sources, as well as conducting their own studies. Thus their correspondence represented a form of lay epidemiology in action, and as such provides a useful pointer to how ‘lay expertise’ may be harnessed in practice. The vast majority of the letters put forward theories and hypotheses about hazards related to early twenty-first century society, either medical technologies, unavoidable by-products of technology, or risks created by modern lifestyles. Given the conclusions of previous studies a surprisingly small minority put forward causes related to vaccines. This disparity is discussed. The findings shed light on the nature of public trust of institutions involved in the definition of risk. They underline the strength of public concern not just about vaccines, but more widely about risks of modern society and technology causing childhood disorders.

Familial deletion within NLGN4 associated with autism and Tourette syndrome

Neuroligin 4 (NLGN4) is a member of a cell adhesion protein family that appears to play a role in the maturation and function of neuronal synapses. Mutations in the X-linked NLGN4 gene are a potential cause of autistic spectrum disorders, and mutations have been reported in several patients with autism, Asperger syndrome, and mental retardation. We describe here a family with a wide variation in neuropsychiatric illness associated with a deletion of exons 4, 5, and 6 of NLGN4. The proband is an autistic boy with a motor tic. His brother has Tourette syndrome and attention deficit hyperactivity disorder. Their mother, a carrier, has a learning disorder, anxiety, and depression. This family demonstrates that NLGN4 mutations can be associated with a wide spectrum of neuropsychiatric conditions and that carriers may be affected with milder symptoms.

Thimerosal-containing vaccines and autistic spectrum disorder: a critical review of published original data.

The issue of thimerosal-containing vaccines as a possible cause of autistic spectrum disorders (ASD) and neurodevelopmental disorders (NDDs) has been a controversial topic since 1999. Although most practitioners are familiar with the controversy, many are not familiar with the type or quality of evidence in published articles that have addressed this issue. To assess the quality of evidence assessing a potential association between thimerosal-containing vaccines and autism and evaluate whether that evidence suggests accepting or rejecting the hypothesis, we systematically reviewed published articles that report original data pertinent to the potential association between thimerosal-containing vaccines and ASD/NDDs. Articles for analysis were identified in the National Library of Medicine's Medline database using a PubMed search of the English-language literature for articles published between 1966 and 2004, using keywords thimerosal, thiomersal, mercury, methylmercury, or ethylmercury alone and combined with keywords autistic disorder, autistic spectrum disorder, and neurodevelopment. In addition, we used the "related links" option in PubMed and reviewed the reference sections in the identified articles. All original articles that evaluated an association between thimerosal-containing vaccines and ASD/NDDs or pharmacokinetics of ethylmercury in vaccines were included. Twelve publications that met the selection criteria were identified by the literature search: 10 epidemiologic studies and 2 pharmacokinetic studies of ethylmercury. The design and quality of the studies showed significant variation. The preponderance of epidemiologic evidence does not support an association between thimerosal-containing vaccines and ASD. Epidemiologic studies that support an association are of poor quality and cannot be interpreted. Pharmacokinetic studies suggest that the half-life of ethylmercury is significantly shorter when compared with methylmercury. Studies do not demonstrate a link between thimerosal-containing vaccines and ASD, and the pharmacokinetics of ethylmercury make such an association less likely. Epidemiologic studies that support a link demonstrated significant design flaws that invalidate their conclusions. Evidence does not support a change in the standard of practice with regard to administration of thimerosal-containing vaccines in areas of the world where they are used.