Serotonin transporter variants play a role in anxiety sensitivity in South African adolescents

Anxiety sensitivity (AS) has predictive potential for the development of anxiety disorders. We investigated the role that gene-environment (G × E) interactions, focussing on childhood trauma (CT) and selected SLC6A4 variants, play in modulating levels of AS in a South African adolescent population.

All adolescents (n = 951) completed measures for AS and CT. Six SLC6A4 polymorphisms were genotyped. G × E influences on AS levels were assessed using multiple linear regression models. Relevant confounders were included in all analyses.

Xhosa (n = 634) and Coloured (n = 317) participants were analysed independently of one another. The 5-HTTLPR-rs25531 L-G haplotype associated with reduced AS among Xhosa adolescents (P = 0.010). In addition, the rs1042173 CC-genotype protected against increased levels of AS in Xhosa participants who had experienced increased levels of CT (P = 0.038). Coloured males homozygous for the S-allele had significantly increased levels of AS compared to Coloured males with at least one L-allele (P = 0.016).

This is the first study to be conducted on AS in adolescents from two ethnically diverse populations. Results indicate that the L-G haplotype confers protection against high AS levels in a Xhosa population. Furthermore, increased CT was found to protect against high levels of AS in Xhosa rs1042173 CC-carriers.