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Using genomics for birth defects epidemiology: Can epigenetics cut the GxE gordian knot?


  • Jan M. Friedman

    Corresponding author
    1. Department of Medical Genetics, University of British Columbia, and Child and Family Research Institute, Vancouver, British Columbia, Canada
    • Child and Family Research Institute, Box 153, 4500 Oak Street, Vancouver, British Columbia, Canada V6H 3N1
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Most birth defects are etiologically complex disorders caused by combinations of genetic and environmental factors, but most studies of birth defect etiology have examined only genetic factors or only environmental factors and have not considered interactions among them. Genome-wide epigenetic studies, which use the same genomic technologies that have revolutionized our ability to identify genetic causes of disease, provide an attractive way to study gene-environment interactions. However, finding an association between epigenetic variation and an etiologically complex birth defect without knowledge of the genetic variation and environmental exposures affecting the individuals who were studied usually provides little or no information regarding the cause of the disorder. In order for genome-wide studies of epigenetic variation to contribute to our understanding of the causes of birth defects, these studies must be combined with studies of environmental exposures and studies of genetic variation in the same subjects. Under such circumstances, epigenetic studies may help to establish the molecular basis for gene-environment interactions. © Birth Defects Research (Part A), 2011. © 2011 Wiley Periodicals, Inc.