Future Prospects in Respiratory Syncytial Virus Genetics

Host genes, together with viral and environmental factors, determine the susceptibility, severity and course of respiratory syncytial virus infections. The course of infection is influenced by several frequently occurring gene variants that especially appear to influence the innate immune system and the regulation of the T helper (Th) type 1/Th2 cytokine pathways. Naturally occurring polymorphisms in certain genes have been associated with a severe course of respiratory syncytial virus infection. Genetic association between interleukin (IL)-4, IL-4Rα and IL-10 polymorphisms and respiratory syncytial virus bronchiolitis differ between children younger and older than 6 months, indicating a different pathogenesis in these subsets of patients. Knowledge of host genetic variants adds to our understanding of pathogenesis, and may identify critical steps to which prevention and therapy may be directed.