We designed a study to identify loci associated with inter-individual variation in peripheral blood absolute lymphocyte counts, an immunological quantitative trait, which is correlated with asthma in the Hutterites (25). Our approach was to integrate gene expression profiling with GWAS data (Fig. 1; see Supplementary Material, Table S1 for summary of results). Specifically, we conducted a GWAS for peripheral blood lymphocyte counts in Hutterites, and characterized genome-wide gene expression levels in LCLs from an overlapping sample of Hutterites, chosen from the tails of the lymphocyte count distribution in this population.
