Bronchiolitis is a major cause of hospitalization among infants. Severe bronchiolitis is associated withlater asthma, suggesting a common genetic predisposition. Genetic background of bronchiolitis is notwell characterized. To identify polymorphisms associated with bronchiolitis, we conducted a genomewideassociation study (GWAS) in which 5,300,000 single nucleotide polymorphisms (SNPs) were testedfor association in a Finnish–Swedish population of 217 children hospitalized for bronchiolitis and 778controls. The most promising SNPs (n = 77) were genotyped in a Dutch replication population of 416cases and 432 controls. Finally, we used a set of 202 Finnish bronchiolitis cases to further investigatecandidate SNPs. We did not detect genome-wide significant associations, but several suggestiveassociation signals (p were nominally associated (p (eQTL) for KCND3, previously shown to be associated with occupational asthma. In the additionalset of Finnish cases, the association for another SNP (rs9591920) within a noncoding RNA locus wasfurther strengthened. Our results provide a first genome-wide examination of the genetics underlyingbronchiolitis. These preliminary findings require further validation in a larger sample size.</p
