MONOSOMY-X AS A RECURRING SOLE CYTOGENETIC ABNORMALITY ASSOCIATED WITH MYELODYSPLASTIC DISEASES

Solitary loss of the X chromosome is associated with Turner syndrome a nd not hematological disorders. We describe five patients with non-con stitutional loss of the X chromosome as the sole cytogenetic abnormali ty in their bone marrow. Three of the five patients had myelodysplasti c syndrome (MDS), one case had AML M-6 with evidence suggestive of an evolving MDS, and the last patient had a dysplastic marrow. A review o f the literature identified sporadic reports of an association of mono somy X and several hematologic disorders, as well as a few solid tumor s. In this series of patients, monosomy Xas a sole non-constitutional cytogenetic abnormality in bone marrow is associated with myelodysplas tic diseases. In addition, fluorescence in situ hybridization analysis with an X centromere probe indicated that monosomy X was present in e rythroid precursors, myeloblasts, promyelocytes, myelocytes, metamyelo cytes, granulocytes, and monocytes, while mature lymphocytes presented with two copies of the X chromosome. The molecular cytogenetic eviden ce supports the diagnosis of a myelodysplastic disorder in these cases and documents the potential role of FISN in hematological diseases. ( C) Elsevier Science Inc., 1997.