RT Journal Article SR Electronic T1 Genetic variants associated with severe pneumonia in A/H1N1 influenza infection JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 604 OP 610 DO 10.1183/09031936.00020611 VO 39 IS 3 A1 J. Zúñiga A1 I. Buendía-Roldán A1 Y. Zhao A1 L. Jiménez A1 D. Torres A1 J. Romo A1 G. Ramírez A1 A. Cruz A1 G. Vargas-Alarcon A1 C-C. Sheu A1 F. Chen A1 L. Su A1 A.M. Tager A1 A. Pardo A1 M. Selman A1 D.C. Christiani YR 2012 UL http://erj.ersjournals.com/content/39/3/604.abstract AB The A/H1N1 influenza strain isolated in Mexico in 2009 caused severe pulmonary illness in a small number of exposed individuals. Our objective was to determine the influence of genetic factors on their susceptibility. We carried out a case–control association study genotyping 91 patients with confirmed severe pneumonia from A/H1N1 infection and 98 exposed but asymptomatic household contacts, using the HumanCVD BeadChip (Illumina, San Diego, CA, USA). Four risk single-nucleotide polymorphisms were significantly (p<0.0001) associated with severe pneumonia: rs1801274 (Fc fragment of immunoglobulin G, low-affinity IIA, receptor (FCGR2A) gene, chromosome 1; OR 2.68, 95% CI 1.69–4.25); rs9856661 (gene unknown, chromosome 3; OR 2.62, 95% CI 1.64–4.18); rs8070740 (RPA interacting protein (RPAIN) gene, chromosome 17; OR 2.67, 95% CI 1.63–4.39); and rs3786054 (complement component 1, q subcomponent binding protein (C1QBP) gene, chromosome 17; OR 3.13, 95% CI 1.89–5.17). All SNP associations remained significant after adjustment for sex and comorbidities. The SNPs on chromosome 17 were in linkage disequilibrium. These findings revealed that gene polymorphisms located in chromosomes 1 and 17 might influence susceptibility to development of severe pneumonia in A/H1N1 infection. Two of these SNPs are mapped within genes (FCGR2A, C1QBP) involved in the handling of immune complexes and complement activation, respectively, suggesting that these genes may confer risk due to increased activation of host immunity.