Figure 2.

Linkage disequilibrium (LD) between variants at the 17q12–21.1 locus among African American SAPPHIRE (Study of Asthma Phenotypes and Pharmacogenomic Interactions by Race–Ethnicity) participants without asthma but (A) homozygous for European ancestry and (B) homozygous for African ancestry. The haplotype block containing the most significant association for early-onset asthma is noted (black circle) and (C) shown in greater detail. The degree of pairwise LD (r² × 100) between two markers is shown in each square; darker shaded squares and higher numbers (range, 0–100) denote higher LD.