The Roles of Environmental Risks and GEX in Increasing ASD Prevalence

Studies of ASD have reported progressively higher prevalence estimates. Evidence suggests that most of the increase is attributable to the combination of greater public awareness, a broadening of the ASD diagnostic criteria, lower age at diagnosis, diagnostic substitution and better case ascertainment. If increased prevalence is even partially attributable to a true increase in incidence, such a rise is likely to be attributable to increased exposure to environmental factors that may enhance expression of genetic vulnerability factors to produce ASD symptoms and disorder.

This project addresses these issues by measuring ASD cumulative incidence in a very large total population sample and assessing the role of environmental factors and genome-environment interactions (GmXE) in ASD incidence and etiology. Detecting the etiologic substrates of ASD is challenging because of difficulties largely arising from the complexity of ASD genetics, including GmXE, insufficient sample sizes (given genetic and phenotypic heterogeneity), and the use of mainly clinical samples that may reflect biased selection. This project is designed to overcome these obstacles.Focus areas of this project are: 1) ASD Incidence; 2) Environmental Impact on ASD Incidence and Phenotype; 3) GmXE and Biobank. Most importantly, this project is community based. Relationships have been built with city and school administrators. Public lectures on ASD have been provided for teachers and community members. Private, one-on-one sessions have been held to provide parents who completed confirmative diagnostic assessments with more information regarding the meaning of their diagnoses, etiology, natural course, prognosis, and treatment.

Mental health related disorders have been hidden and stigmatized in Korea, but this project continues to show school and city officials that early assessment and intervention can enhance the success of children. With project support, a city has successfully launched a public program, "Sound Schools Project," which screens children as they enter the school system. Children who screen positive are now able to receive comprehensive psychiatric evaluations and intervention services, all without charge. Leveraging established infrastructure and research design in the community, we continue to examine the 7-year cumulative incidence of ASD in a prospective design for successive birth cohorts since 2007. Additionally, a genetic epidemiological study of ASD is underway with an epidemiologically-ascertained Korean ASD cohort.