Asthma may be caused by changes in a baby’s DNA if their mother smokes during pregnancy, according to researchers.
A study at the University of Southern California in LA has suggested that a process called DNA methylation may take place while the baby is in the womb.
The process affects cell function and alters genes before the baby is born, the researchers told delegates at the American Thoracic Society conference in Denver.
Experts noticed DNA methylation-related changes in the AXL gene in children whose mothers smoked in pregnancy.
The AXL gene plays an important role in many human cancers and in the way the body fights infection.
“We found that children exposed to maternal smoking in utero had a 2.3% increase in DNA methylation in AXL,” said Carrie Breton, assistant professor of preventive medicine from the University of Southern California.
“These results confirm results from a prior study and present compelling evidence that environmental exposure to tobacco smoke during pregnancy may alter DNA methylation levels.”
Previous research has shown a link between grandmothers smoking and their grandchild’s risk of asthma.
In the latest study, the link between maternal smoking and asthma was stronger in girls than in boys.