Fragile sites at 16q22 are not at the breakpoint of the chromosomal rearrangement in AMMoL.

There is much speculation about fragile sites on human chromosomes predisposing to specific chromosome rearrangements seen in cancer. Acute myelomonocytic leukemia is characterized by neoplastic chromosome rearrangements involving band 16q22 in patients who carry the rare fragile site at 16q22. This specific leukemic breakpoint is within the metallothionein gene cluster, which is here shown to be proximal to the rare fragile site (FRA16B) and to a common fragile site (FRA16C) in this region. Hence neither of these fragile sites are at the breakpoint in this leukemic chromosomal rearrangement.