A Genome-Wide Association Study of Respiratory Syncytial Virus Infection Severity in Infants

Abstract

Background Respiratory syncytial virus (RSV) is a significant cause of infant morbidity and mortality worldwide; however, understanding the genetic risk factors of severe RSV is incomplete. Neutrophils and monocytes have been previously identified as major cell subsets involved in airway inflammation, however the pathophysiology of these events is also not fully characterised. Given that the majority of children experience at least one RSV infection by the age of two years, but not all develop severe disease, we used genomic and transcriptomic data to explore potential mechanistic biomarkers of disease severity. Methods We conducted a genome-wide association study (GWAS) to investigate the genetic factors underlying RSV severity, assessed by the ReSVinet scale, in a cohort of 251 infants aged from 1 week old to 1 year of age. Genotyping data was collected from multiple European study sites as part of the RESCEU Consortium. Data and were analysed following quality control and genotype imputation using the TOPMed server. Generalised linear regression models were employed to assess the impact of genotype on RSV severity. Matrix eQTL in R was used to model the impact of candidate SNPs genotype on gene expression as measured by microarray. Results While no SNPs reached the genome-wide statistical significance threshold (p < 5 × 10−8), we identified 816 candidate SNPs with a p-value of < 1 × 10−4 and 75 SNPs with a p-value of < 1 × 10−5. Subsequent functional annotation of candidate SNPs highlighted variants previously identified in GWAS studies of inflammatory diseases, and genes relevant to neutrophil trafficking and cytoskeletal functions, including LSP1 and RAB27A. Furthermore, the eQTL analysis revealed that SNPs within the RAB27A locus significantly altered gene expression (FDR p < 0.05). Conclusions These findings may provide insights into genetic mechanisms driving severe RSV infection, offering biologically relevant information for future investigations.