We tested for the association between nine SNPs in TGFB1 and indicators of asthma severity (lung function, airway responsiveness, and disease exacerbations) in two cohorts: 416 Costa Rican parent-child trios and 465 families of non-Hispanic white children in the Childhood Asthma Management Program (CAMP).
IL4-RA Q551R and TGF-beta1C-509T are single nucleotide polymorphism loci with significant association to childhood asthma, but they do not have synergistic effects.