Genetic Architecture of Abdominal Aortic Aneurysm in the Million Veteran Program
Authors: Derek Klarin, Shefali Setia Verma, Renae Judy, Ozan Dikilitas, Brooke N. Wolford, Ishan Paranjpe, Michael G. Levin, Cuiping Pan, Catherine Tcheandjieu, Joshua M. Spin, Julie Lynch, Themistocles L. Assimes, Linn Åldstedt Nyrønning, Erney Mattsson, Todd L. Edwards, Josh Denny, Eric Larson, Ming Ta Michael Lee, David Carrell, Yanfei Zhang, Gail P. Jarvik, Ali G. Gharavi, John Harley, Frank Mentch, Jennifer A. Pacheco, Hakon Hakonarson, Anne Heidi Skogholt, Laurent Thomas, Maiken Elvestad Gabrielsen, Kristian Hveem, Jonas Bille Nielsen, Wei Zhou, Lars Fritsche, Jie Huang, Pradeep Natarajan, Yan V. Sun, Scott L. DuVall, Daniel J. Rader, Kelly Cho, Kyong-Mi Chang, Peter W.F. Wilson, Christopher J. O’Donnell, Sekar Kathiresan, Salvatore T. Scali, Scott A. Berceli, Cristen Willer, Gregory T. Jones, Matthew J. Bown, Girish Nadkarni, Iftikhar J. Kullo, Marylyn Ritchie, Scott M. Damrauer, Philip S. Tsao, J. Michael Gaziano, Rachel Ramoni, Jean Beckham, Jim Breeling, Kyong-Mi Chang, Grant Huang, Sumitra Muralidhar, Christopher J. O’Donnell, J.P. Casas Romero, Philip S. Tsao, Sumitra Muralidhar, Jennifer Moser, Stacey B. Whitbourne, Jessica V. Brewer, John Concato, Stuart Warren, Dean P. Argyres, Philip S. Tsao, J. Michael Gaziano, Brady Stephens, Mary T. Brophy, Donald E. Humphries, Nhan Do, Shahpoor Shayan, Xuan-Mai T. Nguyen, Christopher J. O’Donnell, Saiju Pyarajan, Philip S. Tsao, Kelly Cho, Saiju Pyarajan, Elizabeth Hauser, Yan Sun, Hongyu Zhao, Peter Wilson, Rachel McArdle, Louis Dellitalia, John Harley, Clement J. Zablocki, Jeffrey Whittle, Jean Beckham, John Wells, Salvador Gutierrez, Gretchen Gibson, Laurence Kaminsky, Gerardo Villareal, Scott Kinlay, Junzhe Xu, Mark Hamner, Kathlyn Sue Haddock, Sujata Bhushan, Pran Iruvanti, Michael Godschalk, Zuhair Ballas, Malcolm Buford, Stephen Mastorides, Jon Klein, Nora Ratcliffe, Hermes Florez, Alan Swann, Maureen Murdoch, Peruvemba Sriram, Shing Shing Yeh, Ronald Washburn, Darshana Jhala, Samuel Aguayo, David Cohen, Satish Sharma, John Callaghan, Kris Ann Oursler, Mary Whooley, Sunil Ahuja, Amparo Gutierrez, Ronald Schifman, Jennifer Greco, Michael Rauchman, Richard Servatius, Mary Oehlert, Agnes Wallbom, Ronald Fernando, Timothy Morgan, Todd Stapley, Scott Sherman, Gwenevere Anderson, Philip Tsao, Elif Sonel, Edward Boyko, Laurence Meyer, Samir Gupta, Joseph Fayad, Adriana Hung, Jack Lichy, Robin Hurley, Brooks Robey, Robert Striker
Journal: Circulation (2020)

Abdominal aortic aneurysm (AAA) is an important cause of cardiovascular mortality; however, its genetic determinants remain incompletely defined. In total, 10 previously identified risk loci explain a small fraction of AAA heritability.We performed a genome-wide association study in the Million Veteran Program testing ≈18 million DNA sequence variants with AAA (7642 cases and 172 172 controls) in veterans of European ancestry with independent replication in up to 4972 cases and 99 858 controls. We then used mendelian randomization to examine the causal effects of blood pressure on AAA. We examined the association of AAA risk variants with aneurysms in the lower extremity, cerebral, and iliac arterial beds, and derived a genome-wide polygenic risk score (PRS) to identify a subset of the population at greater risk for disease.Through a genome-wide association study, we identified 14 novel loci, bringing the total number of known significant AAA loci to 24. In our mendelian randomization analysis, we demonstrate that a genetic increase of 10 mm Hg in diastolic blood pressure (odds ratio, 1.43 [95% CI, 1.24-1.66]; P=1.6×10-6), as opposed to systolic blood pressure (odds ratio, 1.06 [95% CI, 0.97-1.15]; P=0.2), likely has a causal relationship with AAA development. We observed that 19 of 24 AAA risk variants associate with aneurysms in at least 1 other vascular territory. A 29-variant PRS was strongly associated with AAA (odds ratioPRS, 1.26 [95% CI, 1.18-1.36]; PPRS=2.7×10-11 per SD increase in PRS), independent of family history and smoking risk factors (odds ratioPRS+family history+smoking, 1.24 [95% CI, 1.14-1.35]; PPRS=1.27×10-6). Using this PRS, we identified a subset of the population with AAA prevalence greater than that observed in screening trials informing current guidelines.We identify novel AAA genetic associations with therapeutic implications and identify a subset of the population at significantly increased genetic risk of AAA independent of family history. Our data suggest that extending current screening guidelines to include testing to identify those with high polygenic AAA risk, once the cost of genotyping becomes comparable with that of screening ultrasound, would significantly increase the yield of current screening at reasonable cost.