A gene known to be involved in the development of post-traumatic stress disorder has been discovered by researchers.
Investigators at Boston University School of Medicine (BUSM) and Veterans Affairs (VA) Boston Healthcare System, which reported the first positive results of a genome-wide association study (GWAS) of PTSD, suggested that variations in the retinoid-related orphan receptor alpha (RORA) gene are linked to the development of PTSD.
PTSD is a psychiatric disorder defined by serious changes in cognitive, emotional, behavioural and psychological functioning that can occur in response to a psychologically traumatic event.
Previous GWAS studies have linked the RORA gene to other psychiatric conditions, including attention-deficit hyperactivity disorder, bipolar disorder, autism and depression.
"Like PTSD, all of these conditions have been linked to alterations in brain functioning, so it is particularly interesting that one of the primary functions of RORA is to protect brain cells from the damaging effects of oxidative stress, hypoxia and inflammation," said the study's principal investigator Mark W. Miller, PhD, associate professor at BUSM and a clinical research psychologist in the National Center for PTSD at VA Boston Healthcare System.
Participants in the study were approximately 500 male and female veterans and their intimate partners, all of whom had experienced trauma and approximately half of whom had PTSD. The majority of the veterans had been exposed to trauma related to their military experience whereas their intimate partners had experienced trauma related to other experiences, such as sexual or physical assault, serious accidents, or the sudden death of a loved one.
Each participant was interviewed by a trained clinician, and DNA was extracted from samples of their blood.
The DNA analysis examined approximately 1.5 million genetic markers for signs of association with PTSD and revealed a highly significant association with a variant (rs8042149) in the RORA gene. The researchers then looked for evidence of replication using data from the Detroit Neighborhood Health Study where they also found a significant, though weaker, association between RORA and PTSD.
"These results suggest that individuals with the RORA risk variant are more likely to develop PTSD following trauma exposure and point to a new avenue for research on how the brain responds to trauma," said Miller.
The findings have been published online in Molecular Psychiatry.