The epidemiology of autism spectrum disorders.
Autism spectrum disorders (ASDs) are complex, lifelong, neurodevelopmental conditions of largely unknown cause. They are much more common than previously believed, second in frequency only to mental retardation among the serious developmental disorders. Although a heritable component has been demonstrated in ASD etiology, putative risk genes have yet to be identified. Environmental risk factors may also play a role, perhaps via complex gene-environment interactions, but no specific exposures with significant population effects are known. A number of endogenous biomarkers associated with autism risk have been investigated, and these may help identify significant biologic pathways that, in turn, will aid in the discovery of specific genes and exposures. Future epidemiologic research should focus on expanding population-based descriptive data on ASDs, exploring candidate risk factors in large well-designed studies incorporating both genetic and environmental exposure data and addressing possible etiologic heterogeneity in studies that can stratify case groups and consider alternate endophenotypes.
Newschaffer
Craig J
CJ
Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, PA 19102, USA. cnewscha@drexel.edu
Croen
Lisa A
LA
Daniels
Julie
J
Giarelli
Ellen
E
Grether
Judith K
JK
Levy
Susan E
SE
Mandell
David S
DS
Miller
Lisa A
LA
Pinto-Martin
Jennifer
J
Reaven
Judy
J
Reynolds
Ann M
AM
Rice
Catherine E
CE
Schendel
Diana
D
Windham
Gayle C
GC
D001321:Autistic Disorder / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000150:complications; D013723:Teratogens / Q000633:toxicity
D013723:Teratogens