Association of Gene-Gene Interactions with Venous Thromboembolism (VTE): A Pathway-Directed Candidate-Gene Case-Control Study.

Abstract 480 Background: While interaction between Factor V Leiden and other VTE risk exposures (i.e., oral contraceptives, hormone therapy, pregnancy, cancer, minor trauma) compound VTE risk, whether other gene-environment interactions are associated with VTE is largely unknown. Objective: To test gene-environment interactions for an association with VTE. Methods: Cases (n=1488) were Mayo Clinic European-American patients of non-Hispanic ancestry with objectively-diagnosed VTE in the absence of active cancer, venous catheter or antiphospholipid antibodies. Controls (n=1439) were Mayo Clinic outpatients without VTE who were frequency-matched on case age, gender, race, MI/stroke status and state of residence. We selected candidate genes relevant to the anticoagulant, procoagulant, fibrinolytic and innate immunity pathways, focusing on platelet, monocyte, neutrophil and endothelial cell agonists, receptors, ligands, signal transduction and adhesion molecules, granule contents and effectors; plasma proteases and inhibitors; matrix metalloproteases; inflammatory cytokines and receptors; estrogen, progesterone and androgen receptors; co-regulators and enzymes related to estrogen metabolism; important enzymes for catechol, homocysteine, thromboxane A2 and prostacyclin biosynthesis and metabolism; and HMG CoA reductase. For these genes (n=750), we selected all non-synonymous coding single nucleotide polymorphisms ( SNPs ) with minor allele frequency ≥0.5%; the remaining SNPs were selected using an LD tagging algorithm (Carlson et al. AJHG 2004); 479 ancestry-informative markers were also included (total n=13,241 SNPs). Leukocyte genomic DNA was genotyped using a custom Illumina Infinium iSelect platform, including appropriate controls. We tested all pairwise interactions between 12,483 SNPs (12296 autosomal, 187 chromosome X) that passed quality control and each of seven exposures (ever “stress”[defined as ever hospitalized, ever surgery, ever trauma, ever transfemoral procedure or ever leg paresis], ever surgery, ever neurosurgery, ever orthopedic surgery; and among women, ever pregnant, ≥3 pregnancies and ever oral contraceptives/hormone therapy), adjusted for age, gender, MI/stroke status and state of residence, using logistic regression. False discovery rates (q-value) were calculated to estimate the expected fraction of false positive associations due to multiple statistical tests. Results: The mean ± SD case and control ages were 55.3 ± 16.4 and 56.5 ± 15.9 years, respectively, and 51% were female. Analysis of ancestry-informative markers revealed no evidence of population stratification. Among the seven models, a significant interaction (q≤0.05) was found between ever surgery and two genes located on chromosome 1: USF1 (rs2516840, OR=2.1, p=2.0E-06; q=0.02), and F11R (rs790055 & rs790056; OR∼2.29, p∼4E-06; q=0.02); the two F11R SNPs are in complete linkage dysequilibrium ( LD ), and the USF1 SNP is in moderate LD with the F11R SNPs (r2∼0.6). USF1 encodes for upstream transcription factor 1 which regulates many genes involved in lipid and glucose homeostasis. F11R encodes for the platelet F11 receptor (JAM [junctional adhesion molecule], a cell adhesion molecule important for platelet adhesion to cytokine-stimulated endothelial cells. Conclusion: Interaction between surgery and SNPs within USF1 and F11R are associated with significantly increased risks for VTE. These potential associations require confirmation in future replication studies. Disclosures: No relevant conflicts of interest to declare.