Characterization of mutations in GATA1. (A) DHPLC analysis of PCR products of GATA1 exon 2 from DS patients with TMD. The patients' numbers correspond to the numbers in Table 2. Aberrant chromatogram is seen in all patients. (B) The scatter of mutations in exon 2. Arrows indicate the positions of the different mutations found in the patients screened. Arrows placed above the bar represent insertions/deletions; arrows below the bar represent point mutations. Red arrows indicate DS AMKL patients; blue arrows, DS patients with congenital TMD; green arrows, AMKL with acquired trisomy 21. (C) Sequencing of RT-PCR fragments of GATA1 amplified from bone marrow cells of patient 19 at diagnosis and remission. The mutation 392delCC is clearly seen in the sample taken at diagnosis, but the sample taken at remission is normal. (D) Different types of mutations in exon2 of GATA1.