Relative expression of ABCA1 mRNA in leukocytes. (A) Quantitative analysis of ABCA1 mRNA using TaqMan technology and a fluorescent probe located in exon 3. Analysis was performed using the standard curve method. The control population is visualized by the box plots indicating the 10th and 90th percentile (error bars), the median (solid horizontal line), and the mean (dashed line). The relative amount of ABCA1 mRNA in each control is represented as x-fold expression of the SS patient (set as 1, dashed line). Measurements were performed in triplicate. Because ABCA1 mRNA expression did not differ between men and women, a mixed control population is shown. (B) Agarose gel electrophoresis (1.5% agarose gel) of RT-PCR products amplified from leukocyte RNA from the SS patient and 2 controls using primers spanning exon 1-6. The 2 bands correspond to the wild-type (746-bp) and the alternatively spliced (606-bp) transcript. Lane 1, 100-bp marker; lane 4: negative control. (C) Quantitative analysis of the 2 transcripts described in panel B using LightCycler technology. The SS proband showed reduced ABCA1 mRNA levels for both the appropriately spliced (exon 2-3-4) and the alternatively spliced (exon 2-4) transcript. The ratio of the 2 transcripts did not differ between the patient and the controls (column 3). Analyses were performed using the FitPoints calculation method as described in “Patients, materials, and methods.” The control population is visualized by the box plots (details are described in panel A).