Severe reduction of erythroid colonies in RPS19-deficient patients with DBA.

The bar graph shows the number of erythroid and myeloid progenitor colonies from bone marrow cells of RPS19-deficient patients with DBA and a healthy individual. CD34⁺ cells (10 000) from patients with DBA (Patients 1-4) and normal healthy donors were plated in methylcellulose in the presence of erythropoietin (CFU-Es and BFU-Es) or IL-3 and GM-CSF (CFU-M/GM). CFU-Es (hatched bars) were scored on day 7. The number of BFU-E (black bars) and CFU-M/GM (white bars) colonies were scored on day 14. The mean ± SEM for 3 experiments is shown. The frequency of erythroid colonies is significantly reduced in patients versus contols (P < .04, Wilcoxon rank sum test) but no difference was found with regard to CFU-M/GM colonies. One experiment with 3 independent plates is shown.