Hematologic abnormalities and GATA1 mutation analysis by Ss/DHPLC in neonates with DS. (A) Percentage of blasts on blood films from the first week of life in 200 neonates with DS, 17 with TAM (red circles) and 183 without TAM (black circles). (B) Photomicrographs of typical blast cells in a neonate with TAM (top) and in a DS neonate without TAM (bottom). (C) GATA1 mutation analysis in TAM by Ss and DHPLC. (Ci,ii) Mutation analysis of sample DST11. The mutation is detected by both Ss and DHPLC. (Ci) Sanger sequence trace. The arrow points the start of a double sequence trace indicative of an acquired GATA1 mutation. (Cii) DHPLC trace from the same sample (red line, mutant; black line, normal). (Ciii,iv) Mutation analysis of sample DST9. The mutation is detected by DHPLC but not by Ss. (Ciii) Sequence trace. (Civ) DHPLC trace from the same sample (red line, mutant; black line, normal). (D,F,H) Scatter graphs of hematocrit (D), platelet counts (F), and leukocytes (H) in 200 DS neonates in the first week of life, 17 with TAM (red circles) and 183 without TAM (black circles). The horizontal lines show the upper and/or lower limits of the normal neonatal laboratory range (see supplemental Methods). (E,G,I) Photomicrographs of erythrocyte (E), platelet (G), and leukocyte (I) morphologic abnormalities in neonates with DS. (E) Top left: macrocytes (black arrowheads); top right: target cells (white arrowheads); bottom left: dyserythropoietic erythroblasts (fine black arrow); bottom right: basophilic stippling (gray arrow). (G) Examples of giant platelets (GP) (black arrowhead) and megakaryoblasts (white arrowhead), megakaryocyte fragments (MK fragment), and circulating megakaryocytes (MKs) in blood films from DS neonates without TAM (top row) and with TAM (bottom row). (I) Top left: hypogranular neutrophil; top right: pseudo-Pelger neutrophil; bottom left: monocyte with stellate nucleus; bottom right, dysplastic basophil. Scale bars indicate 10 μm. WBC, white blood cell.