A Novel Approach to Link Genetics and Human MRI Identifies AKAP7-Dependent Subicular/Prefrontal Functional Connectivity as Altered in Suicidality.

Abstract

Background: Brain imaging and genetics are fields acquiring data at increasing speed, but more information does not always result in a better understanding of the underlying biology. We developed the ProcessGeneLists (PGL) approach to use genetics and mRNA gene expression data to generate regions of interest for imaging studies.

Methods: We applied PGL to past suicide attempt (ATT): We averaged the mRNA expression levels of genes (n = 130) possibly associated with ATT (p ≤ 10^-3 in a published genome-wide association study, GWAS) in each brain region studied in the Human Allen Brain Atlas (6 ex-vivo brains, 158 to 946 regions/brain have mRNA expression data) and compared that to the averaged mRNA expression levels of all other genes in each region in each brain in the atlas.

Results: PGL revealed 8 regions where "attempt-related genes" were differentially expressed (Wilcoxon test with Bonferroni correction 8.88^-11 = -6) and dorsolateral prefrontal cortex (dlPFC p_FWE < 0.05) in ATT. We genotyped one single nucleotide polymorphism (SNP) in each of the five genes (within 130 from GWAS) with most important subicular expression. AKAP7 (A-Kinase Anchoring Protein 7, important in hippocampal memory processes) showed an interaction between genotype, ATT, and subiculum/dlPFC RSFC.

Conclusion: PGL uncovered a brain function/genotype interaction in ATT by using published GWAS data to inform imaging studies. This could inform individualized therapies in the future.