A genome-wide association study suggests the HLA Class II region as the major susceptibility locus for IgA vasculitis López-Mejías, Raquel Carmona López, Francisco David Castañeda, Santos Genre, Fernanda Remuzgo-Martínez, Sara Sevilla-Pérez, Belén Ortego-Centeno, Norberto Llorca, Javier Ubilla, Begoña Mijares, Verónica Pina, Trinitario Miranda-Filloy, José A. Navas Parejo, Antonio Argila, Diego de Aragües, Maximiliano Rubio, Esteban León Luque, Manuel Blanco-Madrigal, Juan María Galíndez-Aguirregoikoa, Eva Jayne, David Blanco, Ricardo Martín, Javier González-Gay, Miguel A. Vasculitis Genome-wide association study (GWAS) Human leukocyte antigen (HLA) Henoch-Schonlein purpura The genetic component of Immunoglobulin-A (IgA) vasculitis is still far to be elucidated. To increase the current knowledge on the genetic component of this vasculitis we performed the first genome-wide association study (GWAS) on this condition. 308 IgA vasculitis patients and 1,018 healthy controls from Spain were genotyped by Illumina HumanCore BeadChips. Imputation of GWAS data was performed using the 1000 Genomes Project Phase III dataset as reference panel. After quality control filters and GWAS imputation, 285 patients and 1,006 controls remained in the datasets and were included in further analysis. Additionally, the human leukocyte antigen (HLA) region was comprehensively studied by imputing classical alleles and polymorphic amino acid positions. A linkage disequilibrium block of polymorphisms located in the HLA class II region surpassed the genome-wide level of significance (OR = 0.56, 95% CI = 0.46–0.68). Although no polymorphic amino acid positions were associated at the genome-wide level of significance, P-values of potential relevance were observed for the positions 13 and 11 of HLA-DRB1 (P = 6.67E-05, P = 1.88E-05, respectively). Outside the HLA, potential associations were detected, but none of them were close to the statistical significance. In conclusion, our study suggests that IgA vasculitis is an archetypal HLA class II disease. 2018-02-15T10:35:58Z 2018-02-15T10:35:58Z 2017-07-11 journal article López-Mejías, R.; et al. A genome-wide association study suggests the HLA Class II region as the major susceptibility locus for IgA vasculitis. Scientific Reports, 7: 5088 (2017). [http://hdl.handle.net/10481/49560] 2045-2322 http://hdl.handle.net/10481/49560 10.1038/s41598-017-03915-2 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Nature