BABIES BORN OF MOTHERS FACING STRESS CONDITIONS LIKE ICE STORMS CAN HAVE CHANGED GENES

The health impacts of these changes is not very  clear, but the changes in the family of genes related to immunity and sugar metabolism detected in these babies, now teenagers, may put them at a greater risk to develop asthma, diabetes or obesity.

Canadian researchers report that the number of days an expectant mother was deprived of electricity during Quebec's Ice Storm (1998) predicts the epigenetic profile of her child. Scientists from the Douglas Mental Health University Institute and McGill University have detected a distinctive signature in the DNA of children born in the aftermath of the massive Quebec ice storm.

Five months after the event, researchers recruited women who had been pregnant during the disaster and assessed their degrees of hardship and distress in a study called Project Ice Storm. Thirteen years later, the researchers found that DNA within the T cells of 36 children showed distinctive patterns in DNA methylation.

The scientists published their study (“DNA Methylation Signatures Triggered by Prenatal Maternal Stress Exposure to a Natural Disaster: Project Ice Storm”) in PLOS One.

“Prenatal maternal objective hardship was correlated with DNA methylation levels in 1,675 CGs affiliated with 957 genes predominantly related to immune function; maternal subjective distress was uncorrelated,” wrote the investigators. “DNA methylation changes in SCG5 and LTA, both highly correlated with maternal objective stress, were comparable in T cells, peripheral blood mononuclear cells (PBMCs), and saliva cells.”

The team concluded for the first time that maternal hardship predicted the degree of methylation of DNA in the T cells. The epigenetic signature plays a role in the way the genes express themselves. This study is also the first to show that it is the objective stress exposure (such as days without electricity) and not the degree of emotional distress in pregnant women that causes long-lasting changes in the epigenome of their babies.