dup(10q) lacking alpha-satellite DNA in bone marrow cells of a patient with acute myeloid leukemia.

A marker chromosome was identified in leukemic cells on an AML patient. The G-banding pattern resembled on i(10q), but its centromeric position was not clear; in some cells it had a telocentric shape, in others a metacentric or acentric shape. The origin of the marker chromosome was confirmed by FISH, using chromosome-10-specific painting. To determine the centromeric position, C-banding and alpha-satellite probes were applied in FISH, and none of them gave a positive signal. Despite the absence of the centromeric alpha-satellite sequences and the constricted feature of the centromere, the essential centromeric activity was retained in this chromosome, namely, the separation of sister chromatids in anaphase.