RATIONALE: Ambient air pollution (AAP) is linked to asthma outcomes, but predicting individual risk remains challenging. Understanding genetic contributors to AAP sensitivity may help overcome this gap. OBJECTIVES: To determine if single nucleotide polymorphisms (SNPs) are associated with AAP sensitivity in children with asthma. METHODS: We complete a GWAS in pediatric patients with asthma frequently exposed to AAP, comparing patients with exacerbations following spikes in AAP to patients without this temporal association and calculate a polygenic risk score (PRS) for PM MEASUREMENTS AND RESULTS: We included 6023 patients in the GWAS, restricted to the African ancestry cohort due to the association between AAP exposure and race. Three loci reached genome-wide significance, including rs111970601, associated with CO sensitivity (odds ratio [OR] 6.58
P = 1.63 × 10