Genome-wide expression analysis in SCA28 lymphoblasts. (A) HeatMap representing 76 statistically significant probes differentially expressed in SCA28 patients (n = 4) vs controls (n = 6): 41 probes were up-regulated (Fold Change – FC = 2.5-10), and 35 down-regulated (FC = 0.1-0.3). Hierarchical clustering on the left shows that patients’ whole genome profiling clustered together with the exception of the patient P3F (mutation p.Gly671Arg), whose profile was slightly different. (B) Validation of gene expression levels by real time RT-PCR. Data obtained from microarray profiling (grey bars) were comparable to those obtained by RT-PCR on seven SCA28 lymphoblastoid cell lines (black bars with standard error). On the Y-axis, fold change as multiple of the mean value in controls (arbitrarily set to one). On the X-axis, genes tested. (C) Differentially expressed genes clustered in five major functional categories based on function: (1) regulation of cell proliferation; (2) regulation of programmed cell death; (3) response to oxidative stress; (4) cell adhesion, and (5) chemical homeostasis. Numbers in red and green boxes indicate the transcripts up- and down-regulated, respectively. Grey wedge indicate the remaining categories (26 genes downregulated, and 16 gene upregulated).