Unsupervised Modeling And Genome-Wide Association Identify Novel Features Of Allergic March Trajectories

Abstract [from journal]

Background: The allergic march refers to the natural history of allergic conditions during infancy and childhood. However, population-level disease incidence patterns do not necessarily reflect the development of allergic disease in individuals. A better understanding of the factors that predispose to different allergic trajectories is needed.

Objective: Determine the demographic and genetic features that associate with the major allergic march trajectories.

Methods: Presence or absence of common allergic conditions (atopic dermatitis, AD; IgE-mediated food allergy, IgE-FA; asthma; and allergic rhinitis, AR) was ascertained in a pediatric primary care birth cohort of 158,510 subjects. Hierarchical clustering and decision tree modeling was used to associate demographic features with allergic outcomes. Genome-wide association study (GWAS) tested for risk loci associated with specific allergic trajectories.

Results: We found an association between self-identified "Black" race and progression from AD to asthma. Conversely, "Asian or Pacific Islander" race associated with AD to IgE-FA, and "White" race associated with AD to AR. GWAS of trajectory groups identified risk loci associated with progression from AD to Asthma (rs60242841), and AD to AR (rs9565267, rs151041509, rs78171803). Consistent with our epidemiologic associations, rs60242841 is more common in individuals of African ancestry (AA) than European ancestry (EA), while rs9565267 and rs151041509 are more common in EA than AA individuals.

Conclusion: We identify novel associations between race and progression along distinct allergic trajectories. Ancestral genetic differences may contribute to these associations. These results uncover important health disparities, refine the concept of the allergic march, and represent a step towards developing individualized medical approaches for these conditions.