Metaphase cells from patients with balanced reciprocal translocations involving CBFA2. Signals (green) fromCBFA2 probes that were split by the translocation are indicated on the der(21) (long arrow), the partner derivative (short arrow), and the normal 21 (arrowhead) chromosomes in all examples, except as noted. (A) Patient no. 1 with the t(17;21)(q11.2;q22) hybridized with the biotinylated clone wc-6. (B) Patient no. 2, t(5;21) with walking clone 7. (C) Patient no. 3, t(12;21) with wc-8. (D) Patient no. 5, t(15;21) with wc-5. (E) Patient no. 6, t(14;21) with AML21-telomeric cosmid contig. (F) Patient no. 7, t(1;21)(p36;q22) with wc-5. (G) Patient no. 4, t(17;21) with AML21-centromeric contig. The der(21) (long arrow) and normal 21 (arrowhead) were labeled. (H) Patient no. 4, t(17;21) with AML21-telomeric contig. The der(17) (short arrow) and normal 21 (arrowhead) were labeled.