A central question in post traumatic stress disorder (PTSD) research is why some individuals are at a greater risk of developing the disorder than others who face similar levels of trauma exposure.

Rebekah G. Bradley, PhD, Emory University School of Medicine, Atlanta, studied the role the variations of the gene (polymorphisms) FKBP5 has in predicting PTSD symptoms in a sample of highly traumatized, low-income men and women living in an urban area. They wanted to know whether these genetic variations interact with increasing levels of both child abuse and other types of trauma exposure to be a predictor of PTSD symptoms during adulthood.

Psychological risk factors in 900 general medical clinic patients–with significant levels of childhood abuse and other types of trauma–were examined with both a survey and genetic testing (single-neucleotide polymorphism [SNP] genotyping).

Although genetic variations of FKBP5 SNPs did not directly predict PTSD symptoms with patients who did not suffer child abuse, there were 4 variations in FKBP5 that significantly interact with those patients who suffered child-abuse to predict adult PTSD symptom .