Transancestral mapping and genetic load in systemic lupus erythematosus
Authors: Langefeld Carl D. , Ainsworth Hannah C. , Graham Deborah S. Cunninghame , Kelly Jennifer A. , Comeau Mary E. , Marion Miranda C. , Howard Timothy D. , Ramos Paula S. , Croker Jennifer A. , Morris David L. , Sandling Johanna K. , Almlöf Jonas Carlsson , Acevedo-Vásquez Eduardo M. , Alarcón Graciela S. , Babini Alejandra M. , Baca Vicente , Bengtsson Anders A. , Berbotto Guillermo A. , Bijl Marc , Brown Elizabeth E. , Brunner Hermine I. , Cardiel Mario H. , Catoggio Luis , Cervera Ricard , Cucho-Venegas Jorge M. , Dahlqvist Solbritt Rantapää , D’Alfonso Sandra , Da Silva Berta Martins , de la Rúa Figueroa Iñigo , Doria Andrea , Edberg Jeffrey C. , Endreffy Emőke , Esquivel-Valerio Jorge A. , Fortin Paul R. , Freedman Barry I. , Frostegård Johan , García Mercedes A. , de la Torre Ignacio García , Gilkeson Gary S. , Gladman Dafna D. , Gunnarsson Iva , Guthridge Joel M. , Huggins Jennifer L. , James Judith A. , Kallenberg Cees G. M. , Kamen Diane L. , Karp David R. , Kaufman Kenneth M. , Kottyan Leah C. , Kovács László , Laustrup Helle , Lauwerys Bernard R. , Li Quan-Zhen , Maradiaga-Ceceña Marco A. , Martín Javier , McCune Joseph M. , McWilliams David R. , Merrill Joan T. , Miranda Pedro , Moctezuma José F. , Nath Swapan K. , Niewold Timothy B. , Orozco Lorena , Ortego-Centeno Norberto , Petri Michelle , Pineau Christian A. , Pons-Estel Bernardo A. , Pope Janet , Raj Prithvi , Ramsey-Goldman Rosalind , Reveille John D. , Russell Laurie P. , Sabio José M. , Aguilar-Salinas Carlos A. , Scherbarth Hugo R. , Scorza Raffaella , Seldin Michael F. , Sjöwall Christopher , Svenungsson Elisabet , Thompson Susan D. , Toloza Sergio M. A. , Truedsson Lennart , Tusié-Luna Teresa , Vasconcelos Carlos , Vilá Luis M. , Wallace Daniel J. , Weisman Michael H. , Wither Joan E. , Bhangale Tushar , Oksenberg Jorge R. , Rioux John D. , Gregersen Peter K. , Syvänen Ann-Christine , Rönnblom Lars , Criswell Lindsey A. , Jacob Chaim O. , Sivils Kathy L. , Tsao Betty P. , Schanberg Laura E. , Behrens Timothy W. , Silverman Earl D. , Alarcón-Riquelme Marta E. , Kimberly Robert P. , Harley John B. , Wakeland Edward K. , Graham Robert R. , Gaffney Patrick M. , Vyse Timothy J. 
Published: July 2017

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions (P<5 × 10−8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.