PTPRC and Bloom syndrome: As summarized in Figure 1A, significantly lower CD34+/CD45−/dim and CD34+/CD45−/dim/CD133+ CPC levels were observed in BS patients with respect to controls (245 ± 92 vs. 637 ± 96, p < 0.0001; 80 ± 28 vs. 536 ± 88, p < 0.0001, respectively).