Molecular assignment of a translocation breakpoint in acute myeloid leukemia with t(8;21)

An 8;21 translocation is a common chromosome abnormality associated with acute myeloblastic leukemia with maturation (M2 of French‐American‐British (FAB) classification). We have isolated chromosome 21 Not l linking clones; pulsed field gel electrophoresis analysis with one clone (LL263) detected an altered fragment of Not l‐digested leukemic cell DNA carrying t(8;21). The altered fragment was shown to be produced by the 8;21 translocation. The breakpoint in chromosome 21 was located about 13 kb to 100 kb proximal to the LL263 Nod site. Because the LL263 clone has a CpG island and is a short distance from the breakpoint, the clone itself may be considered as a candidate for part of the t(8;21 ) associated gene.