Many studies have reported genetic associations between severe RSV bronchiolitis and SNPs in genes within plausible biological pathways, such as in innate host defense genes (SPA, SPD, TLR4, and VDR), cytokine or chemokine response genes (CCR5, IFN, IL6, IL10, TGFB1), and altered Th1/Th2 immune responses (IL4, IL13).
The common allelic variants of SP-A1, SP-A2, SP-B, SP-C, and SP-D genes are associated with respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), or respiratory syncytial virus (RSV) bronchiolitis.