No association between war-related trauma or PTSD symptom severity and epigenome-wide DNA methylation in Burundian refugees

Background: War-related trauma is associated with varying posttraumatic stress disorder (PTSD) prevalence rates in refugees. In PTSD development, differential DNA methylation (DNAm) levels associated with trauma exposure might be involved in risk versus resilience processes. Studies investigating DNAm profiles related to trauma exposure and PTSD among refugees remain sparse.

Objective: The present epigenome-wide association study investigated associations between war-related trauma, PTSD, and altered DNAm patterns in Burundian refugee families with 110 children and their 207 female and male caregivers.

Method: War-related trauma load and PTSD symptom severity were assessed in structured clinical interviews with standardised instruments. Epigenome-wide DNAm levels were quantified from buccal epithelia using the Illumina EPIC beadchip.

Results: Controlling for biological confounders, no significant epigenome-wide DNAm alterations associated with trauma exposure or PTSD were identified in children or caregivers (FDRs > .05). Co-methylated positions derived as modules from weighted gene correlation network analyses were not significantly associated with either war-related trauma experience in children or caregivers or with PTSD.

Conclusions: These results do not provide evidence for altered DNAm patterns associated with exposure to war-related trauma or PTSD.

HIGHLIGHTS

• The study examines an understudied population in epigenome-wide association studies.
• Burundian refugees’ war-trauma, PTSD, and DNA methylation were studied.
• Epigenome-wide DNA methylation was not significantly associated with war-trauma or PTSD in the conflict-affected sample.