Recurrent duplication of Xq27∼qter in hematological malignancies revealed by multicolor fluorescence in situ hybridization and multicolor banding

Multicolor fluorescence in situ hybridization (M-FISH) experiments were performed to determine the composition of abnormal complex karyotypes in 15 cases of hematological malignancy. Four cases were found to have unsuspected unbalanced X chromosome translocations, which resulted in the presence of extra X chromosome material. We determined the identity of the duplicated chromosome regions using the multicolor banding (mBAND) technique. Xq27∼qter was duplicated in three of the four male cases with an X chromosome abnormality (i.e., in one third of male cases and one fifth of all cases). These preliminary results may point to the existence of a recurrent chromosome abnormality, either translocation at a specific Xq27 locus or duplication of Xq27∼qter.