2 Posttraumatic Stress Symptoms in a Prospective Gene Open Access

Quinn, Jeffrey Francis (2011)

Permanent URL: https://etd.library.emory.edu/concern/etds/cr56n1053?locale=en


On February 18th, 2008 a lone gunman opened fire in a lecture hall at Northern Illinois

University (NIU) killing five and wounding 17 students before taking his own life. As
part of an ongoing study at that university a large number of female students had
completed several trauma related questionnaires before the shooting (n=1045). Follow-up
surveys were launched 17 days after the shooting, and at several time points afterwards,
providing a unique before and after perspective on these individuals' psychological
response to the event. Of the individuals that completed the follow up surveys (n=691)
we obtained salivary samples and successfully extracted DNA for 235. We examined this
cohort two loci previous linked to PTSD, the serotonin transporter SLC6A4, and the
PAC-1 receptor ADCYAP1R1. At SLC6A4, all individuals were genotyped at rs25531,
for the VNTR STin2, and for the length polymorphism 5-HTTLPR. At ADCYAP1R1 we
genotyped all individuals at rs2267735. Using the Distressing Events Questionnaire as
our PTSD measure, we demonstrated that the change in PTSD symptom severity from
pre- to post-shooting was significantly associated with rs2267735, rs25531 and the 5-
HTTLPR/rs25531 multi-marker genotype (p < 0.05). These associations remained
significant after controlling for level of shooting exposure, which was assessed during the
follow up survey. These results demonstrate gene by environment interactions can be
predictive for differential PTSD symptom severity. When examined in a relatively
homogenous sample with shared trauma and known prior levels of child and adult
trauma, these loci may serve as useful predictors of risk for PTSD-related symptoms in
the weeks and months following the trauma.

Table of Contents


Table of Contents
Introduction - 1
Methods - 11
Results - 17
Discussion - 22
References - 27
Tables/Figures - 31

Table 1 - 31

Table 2 - 32

Table 3 - 33

Table 4 - 34

Table 5 - 35

Figure 1 - 36

Figure 2 - 37

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