Meta-analysis Report
Basic Info
| Reference |
Gressier, F.,2013 PMID: 24222274
|
| Citation |
Gressier, F., et al. (2013). "The 5-HTTLPR polymorphism and posttraumatic stress disorder: a meta-analysis." J Trauma Stress 26(6): 645-653. |
| Objective |
Environmental and genetic factors contribute to the development of posttraumatic stress disorder (PTSD). Variation in the 5-HTTLPR polymorphism of the serotonin transporter gene has been hypothesized to affect risk for PTSD. With the aim of investigating this association, we conducted a meta-analysis to shed light on prior controversial results and increase statistical power to detect smaller effect sizes. |
| Study Type |
Candidate gene association study |
| Extract Database |
PubMed and ISI databases |
| Time Range |
until December 2012 |
Detail Info
| Samples |
Twelve studies have been included, all based on trauma-exposed samples. An electronic search of the literature was performed to identify association studies that have investigated the potential influence of the 5-HTTLPR polymorphism on PTSD. Studies were included if they (a) were published, (b) were written in English, (c) included a trauma-exposed population, (d) showed 5-HTTLPR genotypic frequencies, (e) and were case-control association studies that examined the association between the 5-HTTLPR polymorphism and PTSD diagnosis or were association studies that examined the 5-HTTLPR polymorphism in PTSD participants only. |
| Statistic Method |
Individual and pooled 95% con?dence intervals were calculated. A meta-analysis estimates a combined effect from a number of selected studies. The significance of the pooled effect size was determined using a z test. Moreover, data were analyzed using a random effect framework due to the assumption of between-study heterogeneity. Further more, meta-regression analyses of gender and age were performed using Biostat Comprehensive Meta-Analysis Version 2 software. |
| Basic Result |
Taking into account all studies, no association was found between 5-HTTLPR and PTSD (P-value= .10), with evidence of between-study heterogeneity, which could be partly explained by gender differences. In sensitivity analyses, we found an association between SS genotype and PTSD in high trauma-exposed participants (P-value< .001). To be a carrier of the SS genotype seems to represent a risk factor for PTSD in high trauma exposure. Further studies focusing on Gene x Environment interactions are needed to better understand the role of this polymorphism in PTSD. |
Genetic result reported by this study
Normal genetic result reported by this study (count: 1)
| Marker |
Phenotype |
Related Gene |
Statistical Values |
Author Comments |
Marker's Category |
|
5-HTTLPR
|
PTSD |
SLC6A4 |
Association between PTSD and SS genotype: z=1.64, P-value=.10, heterogeneity: X2=40.59, P-value<.001, I2=73. An analysis grouping SS and SL versus LL participants and considering allele frequencies (S vs. L), odds ratio (OR)=0.88, 95%CI=0.67-1.15, z=0.94, P-value=.35; and OR=1.08, 95%CI=0.88-1.32, z=0.72, P-value=.47; heterogeneity: X2= 21.39, P-value=.03, I2= 49, and X2= 28.94, P-value=.002, I2= 62, respectively. |
Random effects indicated no association between PTSD and SS ......
Random effects indicated no association between PTSD and SS genotype. However, there was evidence of high between-study heterogeneity. Egger's test indicated no evidence of publication bias. We explored gender and age as covariates with meta-regression, and found a gender-dependent association, but no influence of age. Consequently, gender explained part of the heterogeneity between studies. We also performed an analysis grouping SS and SL versus LL participants and considering allele frequencies (S vs. L). In both cases no association was found and a high between-study heterogeneity was identified.
More...
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Non-significant |
