Bayesian Inference Associates Rare <i>KDR</i> Variants With Specific Phenotypes in Pulmonary Arterial Hypertension
Emilia M. Swietlik, Daniel Greene, Na Zhu, Karyn Mégy, Marcella Cogliano, Smitha Rajaram, Divya Pandya, Tobias Tilly, Katie A. Lutz, Carrie L. Welch, Michael W. Pauciulo, Laura Southgate, Jennifer M. Martin, Carmen Treacy, Christopher J. Penkett, Jonathan Stephens, Harm Jan Bogaard, Colin Church, Gerry Coghlan, Anna W. Coleman, Robin Condliffe, Christina A. Eichstaedt, Mélanie Eyries, Henning Gall, Stefano Ghio, Barbara Girerd, Ekkehard Grünig, Simon Holden, Luke Howard, Marc Humbert, David G. Kiely, Gábor Kovács, Jim Lordan, Rajiv D. Machado, Robert V. MacKenzie Ross, Colm McCabe, Shahin Moledina, David Montani, Horst Olschewski, Joanna Pepke‐Żaba, Laura Price, Christopher J. Rhodes, Werner Seeger, Florent Soubrier, Jay Suntharalingam, Mark Toshner, Anton Vonk Noordegraaf, John Wharton, James M. Wild, Stephen J. Wort, Allan Lawrie, Martin R. Wilkins, Richard C. Trembath, Yufeng Shen, Wendy K. Chung, Andrew J. Swift, William C. Nichols, Nicholas W. Morrell, Stefan Gräf, Stephen Abbs, Lara Abulhoul, Julian Adlard, Munaza Ahmed, Timothy J. Aitman, Hana Alachkar, David Allsup, Philip Ancliff, Richard Antrobus, Ruth Armstrong, Gavin Arno, Sofie Ashford, William J. Astle, Anthony Attwood, Paul Aurora, Christian Babbs, Chiara Bacchelli, Tamam Bakchoul, Siddharth Banka, Tadbir K. Bariana, Julian Barwell, Joana Batista, Helen Baxendale, Phil Beales, David Bennett, Agnieszka Bierżyńska, Tina Biss, Maria Bitner‐Glindzicz, Graeme C. Black, Marta Bleda, Iulia Blesneac, Detlef Böckenhauer, Sara Boyce, John R. Bradley, Gerome Breen, Paul Brennan, Carole Brewer, Matthew Brown, Andrew C. Browning, Michael J. Browning, Rachel Buchan
Abstract
Background: Approximately 25% of patients with pulmonary arterial hypertension (PAH) have been found to harbor rare mutations in disease-causing genes. To identify missing heritability in PAH, we integrated deep phenotyping with whole-genome sequencing data using Bayesian statistics. Methods: We analyzed 13 037 participants enrolled in the NBR study (NIHR BioResource—Rare Diseases), of which 1148 were recruited to the PAH domain. To test for genetic associations between genes and selected phenotypes of pulmonary hypertension, we used the Bayesian rare variant association method BeviMed. Results: Heterozygous, high impact, likely loss-of-function variants in the kinase insert domain receptor ( KDR ) gene were strongly associated with significantly reduced transfer coefficient for carbon monoxide (posterior probability=0.989) and older age at diagnosis (posterior probability=0.912). We also provide evidence for familial segregation of a rare nonsense KDR variant with these phenotypes. On computed tomographic imaging of the lungs, a range of parenchymal abnormalities were observed in the 5 patients harboring these predicted deleterious variants in KDR . Four additional PAH cases with rare likely loss-of-function variants in KDR were independently identified in the US PAH Biobank cohort with similar phenotypic characteristics. Conclusions: The Bayesian inference approach allowed us to independently validate KDR , which encodes for the VEGFR2 (vascular endothelial growth factor receptor 2), as a novel PAH candidate gene. Furthermore, this approach specifically associated high impact likely loss-of-function variants in the genetically constrained gene with distinct phenotypes. These findings provide evidence for KDR being a clinically actionable PAH gene and further support the central role of the vascular endothelium in the pathobiology of PAH.