APOE-I3 but not APOE-NL shows AEI in Specimen #31. The upper portion shows each APOE isoform and the placement of the SNP used to evaluate its AEI. The middle portion shows representative electropherograms for assessing AEI in APOE-I3 (A) and APOE-NL (B). The lower portion represents quantitative results for genomic DNA, which shows equal representation of each allele, and for cDNA, which shows unequal allelic expression for APOE-I3 but not APOE-NL. Electropherograms were analyzed for AEI by extrapolating the curves to baseline (dashed lines) and then estimating relative allelic areas. These data were normalized relative to standard curves generated from mixtures of allelic clones (Figure 3).