258314 Environmental exposures during pregnancy in Mexican-American women and their effects on epigenetics in newborns

Monday, October 29, 2012 : 4:30 PM - 4:50 PM

Nina Holland, PhD , School of Public Health, University of California Berkeley, Berkeley, CA
Paul Yousefi, MPH , School of Public Health, University of California Berkeley, Berkeley, CA
Karen Huen, MPH, PhD , School of Public Health, University of California Berkeley, Berkeley, CA
Raul Aguilar, PhD , School of Public Health, University of California Berkeley, Berkeley, CA
Vitaly Volberg, MPH , School of Public Health, University of California Berkeley, Berkeley, CA
Lisa Barcellos, PhD , School of Public Health, University of California Berkeley, Berkeley, CA
Hong Quach , School of Public Health, University of California Berkeley, Berkeley, CA
Asa Bradman, PhD , Center for Environmental Research and Children's Health, University of California Berkeley, Berkeley, CA
Brenda Eskenazi, PhD , Center for Environmental Research and Children's Health, University of California Berkeley, Berkeley, CA
     
Epigenetic changes, particularly DNA methylation, play a significant role in mediating effects of environmental exposures on human health and are hypothesized to be major contributing factors to early-life origins of adult disease. The CHAMACOS longitudinal birth cohort study investigates exposure to pesticides and other environmental pollutants in low-income Mexican-American farmworker families; mothers and their children (N=537) were followed from early pregnancy to 9 years of age. We have previously found that trans-placental exposures to several of these pollutants are associated with adverse birth outcomes including shorter gestational duration as well as abnormal reflexes in children at different ages, higher risk of attention disorders, and decreased IQ at age 7. Little is known about DNA methylation and other epigenetic markers in children, and their relationship with maternal exposures during different stages of pregnancy. Global and site-specific DNA methylation was assessed in DNA isolated from cord blood and peripheral blood (clots) of 9 year old CHAMACOS children. We simultaneously interrogated methylation at 485,577 CpG sites from over 20,000 genes across the methylome using the Illumina BeadChip platform. After adjusting for multiple testing, we found that approximately 15.5% of all investigated CpG sites were differentially methylated between children at birth and 9 years of age. More than 2% of CpG sites investigated, in >1,900 genes, showed significant differences in methylation by sex, including 731 CpG sites located in autosomes. Candidate genes and pathways involved in age and sex differentiation, and in response to environmental exposures during pregnancy, have been identified for future analyses of their effects on birth outcomes and other adverse health effects. Unlike genetics, epigenetic mechanisms could be reversible and an enhanced understanding of their role may lead to better protection of pregnant women and children, and improved public health.

Learning Areas:
Environmental health sciences

Learning Objectives:
Demonstrate how epigenetic mechanisms can be used to explain how environmental exposures during pregnancy can affect children's health

Keywords: Environmental Health, Maternal and Child Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have been the principal or co-investigator on multiple federally funded grants. I am also the director of the Children's Environmental Health Laboratory and School of Public Health Biorepository at UC Berkeley. My research involves the role of genetics and epigenetics in susceptibility to environmental exposures.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

Back to: 3423.0: Environmental exposures and biological variability: Defining the exposome in public health research