Analysis of VWF allelic expression. (A) Chromatogram comparison between F1 gDNA sequence (top) and F1 mRNA sequence (bottom) flanking the +1188 SNP. CASA/RkJ sequence encodes a T at this position, A/J a C. The F1 gDNA and mRNA show similar sized superimposed peaks of C and T at this position, consistent with similar mRNA expression from both alleles. (B) Primer extension analysis on gDNA (black symbols), mRNA (gray symbols), and mRNA amplified across an intron (open symbols) at SNP +774 (diamonds) and SNP +7970 (triangles). Symbols represent individual measurements, and all but one sample were assayed in duplicate.