Identification of a functional 339 bp insertion polymorphism in the schizophrenia-associated locus at 10q24.32.

Genome-wide association studies (GWAS) have identified multiple single nucleotide polymorphisms (SNPs) or small indels robustly associated with schizophrenia; however, the functional risk variations remain largely unknown. We investigated the 10q24.32 locus and discovered a 339 bp insertion polymorphism (rs71389983) in complete linkage disequilibrium (LD) with the schizophrenia GWAS risk variant rs7914558. The presence of the insertion at rs71389983 strongly repressed transcriptional activities in luciferase assays. This polymorphism may be a target for future mechanistic research. Our study also underlines the importance and necessity of considering previously underestimated polymorphisms in future genetic studies of schizophrenia.