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Updated: Jun 19, 2026

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Epistatic effect of IL1A and IL4RA genes on the risk of atopy
Kati Adjers1, Tanja Pessi, Jussi Karjalainen
1Department of Microbiology and Immunology, Medical School, University of Tampere, Finland.
Background:
Several studies have demonstrated a linkage or association of the atopic phenotype with T-cell cytokine genes involved in the regulation of the TH1/TH2 balance (eg, IL4, IL13, and their common receptor, IL4RA). We have recently shown that polymorphism of the pro-inflammatory cytokine IL1A gene is strongly associated with atopy.
Objective:
We now examined whether the polymorphisms of IL1A (G/T at +4845) and IL4RA (T/C at +22446) would show an epistatic effect on the risk of atopy.
Methods:
Skin prick tests and gene polymorphism analyses were performed in a population-based sample of asthmatic and nonasthmatic subjects.
Results:
Our results showed that in the nonasthmatic group the previously described elevated risk of atopy in noncarriers of allele T of IL1A (ie, having the genotype GG) was restricted to individuals who were also noncarriers of allele C of IL4RA (genotype TT). This finding applies to the general population of Finland, where 3.3% of adults are asthmatic.
Conclusion:
These data suggest that the IL1A and IL4RA genes show an epistatic effect on the risk of atopy.
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