Genetic determinants of severe respiratory syncytial virus infection and post-bronchiolitis wheeze: A systematic review

Severity of respiratory syncytial virus (RSV) infection is subject to individual variation, and, accordingly, genetic determinants play a role in the risk of developing RSV lower respiratory tract infection (LRTI) in previously healthy infants. A twin study showed that 22% of the individual susceptibility to RSV LRTI is attributable to genetic factors. About half of the infants with RSV LRTI will develop post-bronchiolitis wheeze (PBW). It is unknown whether RSV LRTI and PBW have similar etiology. This systematic review aims to provide insight into the genetic factors influencing susceptibility to RSV LRTI and PBW. Published genetic associations of RSV LRTI with both single nucleotide polymorphisms (SNPs) and haplotypes are shown. Particularly SNPs in innate immunity genes are associated with the pathogenesis of RSV LRTI. However, no genetic variants associated with RSV LRTI have been exactly replicated in other cohorts. A limited number of studies have reported associations between SNPs and PBW, especially in chemokine and Th2 related genes. In conclusion, although RSV LRTI and PBW show similarities in clinical presentation, different genetic factors are important for the development of these diseases in young children.