The role of genetic variability in the SLC6A4, BDNF and GABRA6 genes in anxiety related traits

The aims of this study were to test the individual association of the 5-HTT, BDNF, and GABRA6 genes with anxiety-related traits and to explore putative GxG interactions in a healthy sample. Method: A sample of 937 individuals from the general population completed the TCI questionnaire; a subsample of 553 individuals also filled in a brief version of the NEO inventory. The whole sample was genotyped for the 5-HTTLPR polymorphism (5- HTT gene), the Val66Met polymorphism (BDNF gene) and the T1521C polymorphism (GABRA6 gene). Results: Individuals carrying the TTgenotype of the T1512C polymorphism presented slightly higher scores for Harm Avoidance ( HA ) than C allele carriers (F=2.96, p=0.051). In addition, there was a significant GxG interaction on HA between the 5-HTTLPR and Val66Met polymorphisms (F=3.4, p=0.009). Conclusion: GABRA6 emerges as a putative gene may be involved in the variability of HA. The effect of a significant GxG interaction between the 5-HTT and BDNF genes on HA could explain part of the genetic basis underlying anxiety-related traits.