RT-PCR and Southern blot analysis of the TLS/FUS-ERG chimeric transcripts in patients with t(16; 21)-AML. M, Marker, φX174 HaeIII. The sizes of the transcripts are indicated. The hybridized products were located beneath the corresponding samples. (A) Consistent detection of the transcripts in patient 2. Three types of transcripts (types A, B, and C) were detectable in the samples at the stages of MDS (lane 1), diagnosis of AML (lane 2), CR (4, 7, and 9 months, respectively, after diagnosis of AML, lanes 4 through 6) and relapse (10.5 months after diagnosis, lane 7). A faint transcript of 211 bp (type B) was found in one sample in CR (3 months after diagnosis, lane 3). (B) RT-PCR analysis of the TLS/FUS-ERG gene in patients 8, 19, and 10. Three sized TLS/FUS-ERG chimeric transcripts (type A, B, and C) were noted in the positive control, UTP-12 (lane 1) and all of the sequential samples available at diagnosis (lane 2), CR (lane 3), and relapse (lane 4) in patient 8. A novel sized transcript (type D) was found in patient 19 at diagnosis (lane 5). The results of patient 10 are indicated in lanes 6 through 9: lane 6, at diagnosis; lanes 7 through 9, in CR 6, 11, and 15 months after diagnosis.