Tanima De1, Cristina Alarcon1, Wenndy Hernandez2, Ina Liko3, Larisa H Cavallari4, Julio D Duarte4, Minoli A Perera1. 1. Northwestern University, Department of Pharmacology, Chicago, Illinois. 2. University of Chicago, Section of Genetic Medicine, Department of Medicine, Chicago, Illinois. 3. University of Illinois College of Pharmacy, Department of Pharmacy Practice, Chicago. 4. University of Florida, College of Pharmacy, Center for Pharmacogenomics, Department of Pharmacotherapy and Translational Research, Gainesville.
Abstract
Importance: Major warfarin-related bleeding occurs more frequently in African Americans than in other populations. Identification of potential genetic factors related to this adverse event may help identify at-risk patients. Objective: To identify genetic factors associated with warfarin-related bleeding in patients of African descent at an international normalized ratio (INR) of less than 4. Design, Setting, and Participants: A case-control genome-wide association study involving patients of African descent taking warfarin was conducted in a discovery cohort (University of Chicago [2009-2011] and the University of Illinois at Chicago [2002-2011]), and associations were confirmed in a replication cohort (University of Chicago [2015-2016]). Potential population stratification was examined in the discovery cohort by principal component analysis. Odds ratios (ORs) and 95% CIs were computed for bleeding risk by logistic regression analysis. Summary statistics from the discovery and the replication cohorts were analyzed with a fixed effects meta-analysis. The potential influence of single-nucleotide polymorphisms (SNPs) on gene expression was studied by luciferase expression assays. Exposures: Single-nucleotide polymorphisms associated with warfarin-related bleeding. Main Outcomes and Measures: Major bleeding-defined as bleeding requiring hospitalization, causing a decrease in hemoglobin level of more than 2 g/dL, requiring blood transfusion, or any combination of the 3-while taking warfarin at an INR of less than 4. Results: The discovery cohort consisted of 31 cases (mean age, 60.1 years [SD, 14.9 years], 26 women [83.9%]) and 184 warfarin-treated controls (mean age, 57.1 years [SD, 15.7 years]) with no documented bleeding. The replication cohort consisted of 40 cases (mean age, 55.6 years [SD, 17.3 years], 27 women [67.5%]), and 148 warfarin-treated controls (mean age, 55.4 years [SD, 17.1 years]; 98 women [66.2%]) with no documented bleeding. In the discovery cohort, 4 SNPs in linkage disequilibrium on chromosome 6 (rs115112393, rs16871327, rs78132896, and rs114504854) were associated with warfarin-related bleeding but did not reach genome-wide significance. The SNP rs78132896 occurred in 11 cases (35.5%) and 9 controls (4.9%) in the discovery cohort (OR, 8.31; 95% CI, 3.2-21.5; P < 6.21 × 10-8), and the association was confirmed in the replication cohort (the SNP was present in 14 cases [35.0%] and 7 controls [4.8%]; OR, 8.24; 95% CI, 3.1-25.3, P = 5.64 × 10-5). Genome-wide significance of this SNP was achieved when the cohorts were combined via meta-analysis (OR, 8.27; 95% CI, 4.18-16.38; P = 2.05 × 10-11). These SNPs are found only in people of African descent. In vitro luciferase expression assays demonstrated that rs16871327 (enhancer SNP) and rs78132896 (promoter SNP) risk alleles together increased EPHA7 gene (Entrez Gene 2045) transcription by a mean of 14.95 (SD, 1.7) compared with wild-type alleles (mean, 9.56 [SD, 0.84]; difference, 5.39; 95% CI, 4.1-6.6; P < .001). Conclusions and Relevance: In this preliminary study involving patients of African descent taking warfarin, 4 single-nucleotide polymorphisms in linkage disequilibrium on chromosome 6 were associated with an increased risk of major bleeding at INR of less than 4. Validation of these findings in an independent prospective cohort is required.
Importance: Major warfarin-related bleeding occurs more frequently in African Americans than in other populations. Identification of potential genetic factors related to this adverse event may help identify at-risk patients. Objective: To identify genetic factors associated with warfarin-related bleeding in patients of African descent at an international normalized ratio (INR) of less than 4. Design, Setting, and Participants: A case-control genome-wide association study involving patients of African descent taking warfarin was conducted in a discovery cohort (University of Chicago [2009-2011] and the University of Illinois at Chicago [2002-2011]), and associations were confirmed in a replication cohort (University of Chicago [2015-2016]). Potential population stratification was examined in the discovery cohort by principal component analysis. Odds ratios (ORs) and 95% CIs were computed for bleeding risk by logistic regression analysis. Summary statistics from the discovery and the replication cohorts were analyzed with a fixed effects meta-analysis. The potential influence of single-nucleotide polymorphisms (SNPs) on gene expression was studied by luciferase expression assays. Exposures: Single-nucleotide polymorphisms associated with warfarin-related bleeding. Main Outcomes and Measures: Major bleeding-defined as bleeding requiring hospitalization, causing a decrease in hemoglobin level of more than 2 g/dL, requiring blood transfusion, or any combination of the 3-while taking warfarin at an INR of less than 4. Results: The discovery cohort consisted of 31 cases (mean age, 60.1 years [SD, 14.9 years], 26 women [83.9%]) and 184 warfarin-treated controls (mean age, 57.1 years [SD, 15.7 years]) with no documented bleeding. The replication cohort consisted of 40 cases (mean age, 55.6 years [SD, 17.3 years], 27 women [67.5%]), and 148 warfarin-treated controls (mean age, 55.4 years [SD, 17.1 years]; 98 women [66.2%]) with no documented bleeding. In the discovery cohort, 4 SNPs in linkage disequilibrium on chromosome 6 (rs115112393, rs16871327, rs78132896, and rs114504854) were associated with warfarin-related bleeding but did not reach genome-wide significance. The SNP rs78132896 occurred in 11 cases (35.5%) and 9 controls (4.9%) in the discovery cohort (OR, 8.31; 95% CI, 3.2-21.5; P < 6.21 × 10-8), and the association was confirmed in the replication cohort (the SNP was present in 14 cases [35.0%] and 7 controls [4.8%]; OR, 8.24; 95% CI, 3.1-25.3, P = 5.64 × 10-5). Genome-wide significance of this SNP was achieved when the cohorts were combined via meta-analysis (OR, 8.27; 95% CI, 4.18-16.38; P = 2.05 × 10-11). These SNPs are found only in people of African descent. In vitro luciferase expression assays demonstrated that rs16871327 (enhancer SNP) and rs78132896 (promoter SNP) risk alleles together increased EPHA7 gene (Entrez Gene 2045) transcription by a mean of 14.95 (SD, 1.7) compared with wild-type alleles (mean, 9.56 [SD, 0.84]; difference, 5.39; 95% CI, 4.1-6.6; P < .001). Conclusions and Relevance: In this preliminary study involving patients of African descent taking warfarin, 4 single-nucleotide polymorphisms in linkage disequilibrium on chromosome 6 were associated with an increased risk of major bleeding at INR of less than 4. Validation of these findings in an independent prospective cohort is required.
Authors: Nicolas Prévost; Donna S Woulfe; Hong Jiang; Timothy J Stalker; Patrizia Marchese; Zaverio M Ruggeri; Lawrence F Brass Journal: Proc Natl Acad Sci U S A Date: 2005-07-01 Impact factor: 11.205
Authors: Nita A Limdi; Todd M Brown; Aditi Shendre; Nianjun Liu; Charles E Hill; Timothy M Beasley Journal: Pharmacogenet Genomics Date: 2017-10 Impact factor: 2.089
Authors: Mia Wadelius; Leslie Y Chen; Jonatan D Lindh; Niclas Eriksson; Mohammed J R Ghori; Suzannah Bumpstead; Lennart Holm; Ralph McGinnis; Anders Rane; Panos Deloukas Journal: Blood Date: 2008-06-23 Impact factor: 22.113
Authors: Janine van Loon; Abbas Dehghan; Tang Weihong; Stella Trompet; Wendy L McArdle; Folkert W Asselbergs; Ming-Huei Chen; Lorna M Lopez; Jennifer E Huffman; Frank W G Leebeek; Saonli Basu; David J Stott; Ann Rumley; Ron T Gansevoort; Gail Davies; James J F Wilson; Jacqueline C M Witteman; Xiting Cao; Anton J M de Craen; Stephan J L Bakker; Bruce M Psaty; John M Starr; Albert Hofman; J Wouter Jukema; Ian J Deary; Caroline Hayward; Pim van der Harst; Gordon D O Lowe; Aaron R Folsom; David P Strachan; Nicolas Smith; Moniek P M de Maat; Christopher O'Donnell Journal: Eur J Hum Genet Date: 2015-10-21 Impact factor: 4.246
Authors: Judith Kooiman; Nadja van Hagen; Antonio Iglesias Del Sol; Erwin V Planken; Gregory Y H Lip; Felix J M van der Meer; Suzanne C Cannegieter; Frederikus A Klok; Menno V Huisman Journal: PLoS One Date: 2015-04-23 Impact factor: 3.240
Authors: Robert E Thurman; Eric Rynes; Richard Humbert; Jeff Vierstra; Matthew T Maurano; Eric Haugen; Nathan C Sheffield; Andrew B Stergachis; Hao Wang; Benjamin Vernot; Kavita Garg; Sam John; Richard Sandstrom; Daniel Bates; Lisa Boatman; Theresa K Canfield; Morgan Diegel; Douglas Dunn; Abigail K Ebersol; Tristan Frum; Erika Giste; Audra K Johnson; Ericka M Johnson; Tanya Kutyavin; Bryan Lajoie; Bum-Kyu Lee; Kristen Lee; Darin London; Dimitra Lotakis; Shane Neph; Fidencio Neri; Eric D Nguyen; Hongzhu Qu; Alex P Reynolds; Vaughn Roach; Alexias Safi; Minerva E Sanchez; Amartya Sanyal; Anthony Shafer; Jeremy M Simon; Lingyun Song; Shinny Vong; Molly Weaver; Yongqi Yan; Zhancheng Zhang; Zhuzhu Zhang; Boris Lenhard; Muneesh Tewari; Michael O Dorschner; R Scott Hansen; Patrick A Navas; George Stamatoyannopoulos; Vishwanath R Iyer; Jason D Lieb; Shamil R Sunyaev; Joshua M Akey; Peter J Sabo; Rajinder Kaul; Terrence S Furey; Job Dekker; Gregory E Crawford; John A Stamatoyannopoulos Journal: Nature Date: 2012-09-06 Impact factor: 49.962
Authors: Salina P Waddy; Allen J Solomon; Adan Z Becerra; Julia B Ward; Kevin E Chan; Chyng-Wen Fwu; Jenna M Norton; Paul W Eggers; Kevin C Abbott; Paul L Kimmel Journal: J Am Soc Nephrol Date: 2020-02-20 Impact factor: 10.121
Authors: Victoria M Pratt; Larisa H Cavallari; Andria L Del Tredici; Houda Hachad; Yuan Ji; Lisa V Kalman; Reynold C Ly; Ann M Moyer; Stuart A Scott; Michelle Whirl-Carrillo; Karen E Weck Journal: J Mol Diagn Date: 2020-05-04 Impact factor: 5.568
Authors: Dan M Roden; Howard L McLeod; Mary V Relling; Marc S Williams; George A Mensah; Josh F Peterson; Sara L Van Driest Journal: Lancet Date: 2019-08-05 Impact factor: 79.321
Authors: Tanima De; Honghong Zhang; Cristina Alarcon; Bianca Lec; Juan Avitia; Erin Smithberger; Chuyu Chen; Minnie Horvath; Sara Kwan; Mary Young; Sarbani Adhikari; John Kwon; Jennifer Pacheco; Gail Jarvik; Wei-Qi Wei; Frank Mentch; Hakon Hakonarson; Patrick Sleiman; Adam Gordon; John Harley; Jim Linneman; Scott Hebbring; Loukia Parisiadou; Minoli A Perera Journal: Pharmacogenet Genomics Date: 2022-01-01 Impact factor: 2.089