Association of a Met88Val diazepam binding inhibitor (DBI) gene polymorphism and anxiety disorders with panic attacks.

Several lines of evidence suggest that anxiety disorders have a strong genetic component, but so far only few susceptibility genes have been identified. There is preclinical and clinical evidence for a dysregulation of the central gamma-aminobutyric acid (GABA)-ergic tone in the pathophysiology of anxiety disorders. Diazepam binding inhibitor (DBI) has been suggested to play a pivotal role in anxiety disorders through direct and indirect, i.e. via synthesis of neuroactive steroids, modulation of GABA(A) receptor function. These findings suggest that the DBI gene can be postulated as a candidate for a genetic association study in this disorder. Thus, single nucleotide polymorphisms (SNPs) of the DBI gene were investigated for putative disease associations in a German sample of anxiety disorder patients suffering from panic attacks and matched controls. We were able to detect a significant association between a non-synonymous coding variant of DBI with anxiety disorders with panic attacks. The rare allele of this polymorphism was more frequent in controls than in patients (OR=0.43; 95% CI: 0.19-0.95). In conclusion, these results suggest a central role of DBI genetic variants in the susceptibility for the development of anxiety disorders that are characterized by the occurrence of panic attacks.