Certain mothers who smoke while pregnant are at high risk of passing along genetic damage to their babies, according to study results presented by University of Pittsburgh scientists at the annual American Association for Cancer Research meeting in New Orleans.
"This type of damage is dangerous for pregnant women, and we believe it could also put newborns at an increased risk of cancer," said Marjorie Romkes, Ph.D., assistant professor of environmental and occupational health at the University of Pittsburgh Graduate School of Public Health.
Dr. Romkes is a member of a team of scientists who monitored 290 smoking expectant mothers and nonsmoking pregnant women in an ongoing study evaluating a number of biomarkers of tobacco exposure, genetic susceptibility to cancer and early biological effects of cancer-causing agents. They studied the incidence of mutations in the gene for glycophorin A (GPA), a molecule found in the membrane of red blood cells. Changes in the GPA gene are considered a measure of genetic damage in non-reproductive cells of the body. The scientists also studied various metabolic enzymes that process chemicals found in tobacco smoke.
"We found 18 expectant mothers who had very high frequencies of GPA mutations. A baby born to one of these mothers who was a heavy smoker also had these mutations," said Dr. Romkes. "In addition, among these women with significantly elevated GPA mutation frequencies, each mother was a carrier of at least two 'at-risk' enzyme genotypes."
"At-risk" genotypes are defined as variations in the genes coding for metabolic enzymes, resulting in increased activation or decreased detoxification of cancer-causing toxins.
The researchers also found that as women smoked more heavily, the levels
of some of these enzymes (CYP1A1 and CYP2E1) increased. CYP1A1 and CYP2E1
transform substances in tobacco smoke into dangerous carcinogens that cause
Contact: Lauren Ward
University of Pittsburgh Medical Center