NEW YORK, N.Y. (January 21, 2010) Two recent, separate publications identified regions with higher than expected numbers of autism cases or clusters in California. Using data collected by the California Department of Developmental Services (DDS) on 2.5 million births including almost 10,000 autism cases from 1996-2000, investigators at UC Davis uncovered several clusters of elevated risk for autism. Autism Speaks, the nation's largest autism science and advocacy organization, reviewed these studies and found that the majority of these clusters were found to be strongly associated with higher parental education and, to a lesser extent, with parents of older ages. It is thought that parents with higher levels of education may have better access to the regional diagnostic and service centers in California, as the DDS relies on parents actively seeking services. Thus the distribution of cases is likely influenced by proximity to specialty research and service centers.
However, demographic factors, alone, may not explain the increased numbers of cases in these clusters. The authors propose that other factors, including environmental exposures, may play a role but warrant further investigation to understand their contribution to autism etiology.
"Examination of clusters can help us understand the factors that have led to in increase in autism prevalence over time," said Autism Speaks' Chief Science Officer, Geraldine Dawson, Ph.D.
Similar to the UC Davis study, a second study using data collected by the California DDS, which was conducted by investigators from Columbia University identified a significant cluster of increased risk for autism as well as a set of lower risk clusters in and around Northern Los Angeles. However, rather than looking at incidence of cases by DDS Regional Center catchment area, Mazumdar et. al. examined more than 11,500 autism cases among four million births by place of birth. This approach was used to avoid
|Contact: Jane E. Rubinstein|