A team of researchers has discovered that high levels of lead in moms' blood not only affect the fetal cells of their unborn children, but also their grandchildren.
In the Wayne State University study led by Douglas Ruden, researchers revealed that lead exposure can cause specific changes in DNA methylation, which can be detected in dried blood spots beyond one generation.
The neonatal blood spots from both the mothers and children in this study were obtained from the Michigan Neonatal Biobank, a unique resource that has most of the neonatal dried blood spots from children born in Michigan since 1984.
According to Ruden, epigenetic effects of environmental exposures beyond one generation have not yet been demonstrated in humans prior to this study. He and his team tested the hypothesis that human fetal germ cell exposure to environmental toxins causes epigenetic changes in the newborn blood from a grandchild of an exposed pregnant woman.
The results suggest that lead exposure during pregnancy affects the DNA methylation status of the fetal germ cells, which leads to altered DNA methylation in grandchildren's neonatal dried blood spots, said Ruden, adding that this is the first demonstration that an environmental exposure in pregnant mothers can have an epigenetic effect on the DNA methylation pattern in the grandchildren.
The research team stated that this novel, two-generational study design might be able to identify the genes that may serve as possible candidate biomarkers for future transgenerational risk assessment studies.
The study is published online in Scientific Reports.
