RANTES (a chemoattract of mast cells, eosinophils, baseophils & T-cells) and IL-13 (an inducer of IgE, eosinophilia & bronchial hyperresponsiveness) are asthma & atopy mediators. Two RANTES – 403(GtoA) & -28(CtoG) SNPs and an -1055 IL-13(CtoT) SNP have been shown in Caucasians & Orientals as asthma & atopy risk factors. We studied these SNPs in African Americans with asthma/atopy.

We studied 61 patients (2–74 yr) and 129–157 controls for the -403 RANTES, -28 RANTES, and -1055 IL-13 SNPs. All patients were known to have asthma &/or atopy documented by positive SPT or RAST.

For the −403 RANTES SNP, GG genotype was detected in 26.2% of patients vs. 26.7% in controls, AA genotype in 18% vs. 18.3% in controls and GA genotype in 55.7% vs. 55% in controls. For the −28 RANTES SNP, CC genotype was detected in 96.7% vs. 100% in controls, CG genotype in 3.3% vs. 0% in controls and neither group had GG genotype. On the other hand, for the −1055 IL-13 SNP, CC genotype was detected in 21.3% vs. 39.5% in controls, TT genotype in 19.7% vs. 12.7% in controls, and CT genotype in 59.0% vs. 47.7% in controls.

African American asthmatics/atopics had higher (p 0.04) frequency of the TT mutant gene of the −1055 IL-13 SNP (odd ratio 2.9, 95% CI 1.0-8.0) and of its T mutant allele (p 0.02, odd ratio 1.7, 95% CI 1.1-2.6), which can be used as a predictor marker.