RFLP analysis of genomic DNA. (A) Genomic DNAs digested with Taq I were hybridized with probe M2G3. The restriction map generated from the sequence, dbj0˙00057, is shown on the top: B,BamHI; E, EcoRI; T, Taq I. The Taq I site eliminated by mutations at codon 177 is boxed. Lanes 1, 4, and 5, wild-type; lane 2, patient no. 1 (R177ter); lane 3, patient no. 5 (R177Q). (B) The gene dosage analysis by Southern blotting of theAML1 gene with the Ig heavy chain J region (J_H) gene as control. Genomic DNA was digested withBamHI and hybridized with probes M2G3 and J_H. Lane 1, patient no. 1; lane 2, HL60. (C) Genomic DNAs digested withPst I were hybridized with cDNA probe AP2 that covers exons 3 through 6. The restriction map, based on the same sequence as in (A), is shown on the top. P stands for Pst I sites, among which the one created by mutation C72ins is boxed. Lanes 1 through 3, wild-type; lane 4, patient no. 2. Note that two fragments were newly produced in lane 4 with a reciprocal partial attenuation of the 1.9-kb fragment from which they were derived.