Table 2.
Review of published case-control candidate gene associations studies of PTSD by neurobiological system
| First author | Year | Trauma Exposed Controls? | Trauma Type | Gene Name (Symbol) | Finding |
|---|---|---|---|---|---|
| HPA Axis | |||||
| Bachman | 2005 | yes | Combat | Glucocorticoid Receptor (GCCR) | No significant association between GCCR polymorphisms and PTSD |
| Binder* | 2008 | Yes | Various | FKBP5 | 4 SNPs in FKBP5 significantly interacted with severity of child abuse in prediction of adult PTSD symptoms ps<.0004 |
| Lu | 2008 | No | Not specified | Cannabinoid Receptor Gene (CNR1) | Excess C-A and C-G variants in Caucasian parents of youth with ADHD who report PTSD |
| Locus Coeruleus/Noradrenergic System | |||||
| Lappalainen | 2002 | No | Combat | Neuropeptide Y (NPY) | No significant association between Leu7Pro polymorphism and PTSD |
| Mustapic | 2007 | Yes | Combat | Dopamine Beta-Hydroxylase (DBH) | No association of -1021C/T variant with PTSD; PTSD CC genotype cases had lower DBH activity than non-PTSD CC cases p<.001 |
| Limbic-frontal Neuro-circuitry of Fear | |||||
| Comings | 1991 | No | Combat | Dopamine Receptor D2 (DRD2) | Excess D2A1 allele in PTSD cases p=.007 |
| Comings | 1996 | Yes | Combat | Dopamine Receptor D2 (DRD2) | Excess D2A1 allele in PTSD cases p=.041 |
| 1996 | Yes | Combat | Dopamine Receptor D2 (DRD2) | Excess D2A1 allele in PTSD cases p=.002 | |
| Gelernter | 1999 | No | Combat | Dopamine Receptor D2 (DRD2) | No significant association between D2A1 allele/DRD2 haplotypes and PTSD |
| Young | 2002 | No | Combat | Dopamine Receptor D2 (DRD2) | Excess D2A1 allele only in PTSD cases with harmful drinking p<.001 |
| Voisey | 2008 | Yes | Combat | Dopamine Receptor D2 (DRD2) | Excess C allele in 957C>T in PTSD; no differences in Taq1A or -141delC |
| Segman | 2002 | Yes | Various | Dopamine Transporter (DAT1) | Excess 9-repeat allele in PTSD cases p=.012 |
| Lee | 2005 | No | Various | Serotonin Transporter (SLC6A4) | Excess s allele in PTSD cases p = .04 |
| Lee | 2007 | Yes | Not specified | Serotonin 2A receptor (5-HTR2A) | Excess GG genotype in female PTSD p = .04 |
| Zhang | 2006 | Not specified | Not specified | Brain Derived Neurotrophic Factor (BDNF) | No significant association between three BDNF variants and PTSD |
| Lee | 2006 | Yes | Not specified | Brain derived Neurotrophic Factor (BDNF) | No significant association between BDNF Val66Met and PTSD |
| Kilpatrick* | 2007 | Yes | Hurricane | Serotonin Transporter (SLC6A4) | Significant association between s/s genotype and PTSD in adults with high hurricane exposure and low social support |
| Amstadter* | 2009 | Yes | Hurricane; Various | Regulator of G-Protein Signaling 2 (RGS2) | Significant association between CC genotype and post-hurricane PTSD in adults with high hurricane exposure and low social support; significant association between CC genotype and lifetime PTSD in adults with prior trauma exposure and low social support |
*
= GxE study; PTSD = posttraumatic stress disorder; SNPs = single nucleotide polymorphisms; D2DA1 = Al one allele of DRD2 gene; s allele = short version (versus long) of the serotonin transporter promoter polymorphism.