Uncommon protein-coding variants associated with suicide attempt in a diverse sample of US Army soldiers.

BACKGROUND: Suicide is a societal and public health concern of global scale. Identifying genetic risk factors for suicide attempt can characterize underlying biology and enable early interventions to prevent deaths. Recent studies have described common genetic variants for suicide-related behaviors. Here, we advance this search for genetic risk by analyzing the association between suicide attempt and uncommon variation, exome-wide in a large, ancestrally diverse sample.

METHODS: We sequenced whole genomes of 13,584 soldiers from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS), including 979 with a history of suicide attempt. Uncommon, non-silent protein coding variants were analyzed exome-wide for association with suicide attempt by gene-collapsed and single variant analyses.

RESULTS: We identified 19 genes with variants enriched in individuals with suicide attempt, either through gene-collapsed or single variant analysis (Bonferroni PAdjusted < 0.05). These genes were CIB2, MLF1, HERC1, YWHAE, RCN2, VWA5B1, ATAD3A, NACA, EP400, ZNF585A, LYST, RC3H2, PSD3, STARD9, SGMS1, ACTR6, RGS7BP, DIRAS and KRTAP10-1. Most genes had variants across multiple genomic ancestry groups. Seventeen of these genes were expressed in healthy brain tissue, with seven genes expressed at highest levels in brain vs. other tissues. Brains from individuals deceased from suicide aberrantly expressed RGS7BP (PAdjusted =0.035) in addition to nominally significant genes including YWHAE, DIRAS2 and ACTR6, all of which have reported associations with other mental disorders.

CONCLUSIONS: These results advance the molecular characterization of suicide attempt behavior and support the utility of whole genome sequencing for complementing the findings of GWAS in suicide research.