The study of genetic variants that contribute to autism has been greatly facilitated by repositories of DNA collected from people with the disorder and their families in clinical settings. Epidemiologic studies take this a step further by collecting data from entire communities; these types of studies provide a more comprehensive description of autism's clinical symptoms and genetic variation than those that only include children who have already been diagnosed. Large-scale population studies are particularly valuable, as they allow researchers to conduct risk assessments for a broad range of people.
Young Shin Kim, of Yale University, and her colleagues are currently undertaking such an effort in Cheonan, South Korea. Their study will take advantage of the ongoing Korean Environmental Studies I and II, which have obtained blood or saliva samples from 10,000 6- to 12-year-old Korean children. Kim's team plans to collect autism phenotype data — from standard behavioral measures such as the Social Responsiveness Scale and Autism Spectrum Screening Questionnaire — as well as DNA from biological samples from all 10,000 children.
In a relatively short time — the project is expected to take 18 to 24 months — the researchers will have assembled a huge repository of autism-related data from a genetically homogeneous cohort; Koreans originate from a single population, and marriage to people of other ethnicities is uncommon. The researchers believe this consistency boosts the statistical power of their data and provides a unique resource for discovering both common and rare genetic variants that cause or increase the risk of autism, understanding how these genes underlie the disorder's clinical traits, assessing the distribution of these traits and variants, and uncovering gene-environment interactions that lead to development of the disorder.