Multiple independent GATA1 mutations are present. (A) Radiolabeled GATA1 exon 2 PCR products generated from genomic template of patient L07 and L15's neonatal blood spot (BG) and a healthy control (N) were separated on a polyacrylamide gel. The wild-type GATA1 product is marked (Wt). Patient L07 has a single wild-type-sized band and 2 extra bands (bands 1 and 2). L15 has only one wild-type-sized product (panel C, band 3). (B-C) Radiolabeled GATA1 exon 2 bands from patient L07 and L15's BG shown in panel A were excised, cloned, and sequenced. Sequence chromatograms of clones from patient L07 (B) and L15 (C) are shown. Mutant traces are illustrated, and wild-type (Wt) traces are depicted for comparison.