The Quebec Ice Storm of 1998 was a devastating time that plunged more than 3 million Quebecers into frigid darkness without electricity for as long as 45 days. Now, more than 15 years later, researchers from McGill University and the Douglas Mental Health University are finding out that the length of time a pregnant woman went without electricity during this time predicts her child’s epigenetic profile.
Scientists have discovered a unique DNA ‘signature’ of children who were in the womb while the massive ice storm occurred. Five months following the disaster, women who were pregnant during the storm were recruited and their degrees of hardship and distress were assessed in a large study known as Project Ice Storm.
Part of the team of scientists who carried out this study were three researchers from McGill University: Lei Cao-Lei of the Psychological Research Division, Douglas Institute Research Center and Department of Psychiatry, along with Moshe Szyf of the Department of Pharmacology and Therapeutics, Sackler Program for Epigenetics and Developmental Psychobiology, and Suzanne King of the Psychological Research Division, Douglas Institute Research Center and Department of Psychiatry.
Thirteen years after the women had been recruited, these scientists found that the DNA in T cells – a type of cell crucial to the immune system – displayed distinct methylation patterns in 36 children whose mothers endured the Ice Storm while pregnant. This epigenetic signature influences whether or not certain genes are expressed. For the first time, it was found that maternal hardship could predict the amount of DNA methylation in the babies’ T cells. It’s also the first time a study has showed that enduring changes to the babies’ epigenome occurs due to a mother’s objective exposure to stress and not the level of emotional distress she experiences.
The researchers found that prenatal maternal objective hardship – for example, the amount of time a pregnant woman went without electricity, any injury she experienced as a result of the storm, the extent of damage that was done to her house – was correlated with DNA methylation levels in 1,675 CGs linked to 957 genes that are largely related to immune function. Specifically, they stated that “DNA methylation changes in SCG5 and LTA were both highly correlated with maternal objective stress” and that these methylation changes were comparable in cells such as T-cells, saliva cells, and peripheral blood mononuclear cells (PBMCs), which aim to help fight infection and adapt to intruders as part of the immune system.
The long term repercussions of the DNA methylation changes in these children are not entirely understood. However, the epigenetic signature which affects a group of genes related to sugar metabolism and immunity may put these teenagers at risk for developing health complications such as diabetes, obesity, or asthma. In June 2014, results from Project Ice Storm were reported in BioMed Research International and Psychiatry Research, demonstrating a connection between prenatal maternal stress (PNMS) and symptoms of asthma and autism, in these children.
Researchers involved in Project Ice Storm have been following a group of nearly 150 families in order to assess the effects the stressful ice storm has had on the children of women who were pregnant during or became pregnant shortly after the disaster. Project Ice Storm continues to study these Ice Storm Babies, who are now in their teenage years.
Source: Learn all about it and read more about their findings here: Lei Cao-Lei, Renaud Massart, Matthew J. Suderman, Ziv Machnes, Guillaume Elgbeili, David P. Laplante, Moshe Szyf, Suzanne King. DNA Methylation Signatures Triggered by Prenatal Maternal Stress Exposure to a Natural Disaster: Project Ice Storm. PLoS ONE. 2014.
Reference: DNA Signature Found in Ice Storm Babies. Douglas Mental Health University Institute. 2014.