Identification of functional SNP rs2038479 in a novel, lineage-specific promoter. (A) Relative DNM3 transcript levels in PLTs from persons homozygous for the major or minor allele of variant rs2038479. Quantitative real-time RT-PCR results with a probe specific for the novel exon 2B-exon 3 boundary (left) versus the annotated exon 2-exon 3 boundary (right) (n = 24/23, unpaired t test, including Welch correction for unequal variances). (B) Relative transcript abundance of tissues as measured by quantitative PCR. MK indicates MK; EB, erythroblast; and CB, cerebellum. n = 3. Error bars represent SD, relative to EB = 1. (C) Quantitative PCR comparison of 2 major DNM3 transcripts during MK maturation (n = 3). Error bars represent SD, relative to annotated transcript day 0 = 1. (D) In vitro dual Luciferase reporter assay of promoter activity of the region 5′ of alternative exon 2B, including variant rs2038479 compared with the consensus promoter 5′ of exon 1. Left: Megakaryocytic CHRF cells. Right: Medulloblastoma cells 1603MED, relative to empty firefly vector = 100%. Error bars represent SD. The significance of the effect of the variant at the alternative promoter (P = .002) was determined using a linear mixed model based on 3 independent experiments with 3 replicates per experiment.