ISODICENTRIC (X)(Q13) IN HEMATOLOGICAL MALIGNANCIES - PRESENTATION OF5 NEW CASES, APPLICATION OF FLUORESCENCE IN-SITU HYBRIDIZATION (FISH)AND REVIEW OF THE LITERATURE

Idic(X)(q13) represents a rare but recurrent chromosomal abnormality i n haematological malignancies. We present five new cases characterized by this particular aberration and review the literature on this subje ct, The patients were elderly females with a diagnosis of refractory a naemia (1/5), refractory anaemia with ringed sideroblasts (2/5), chron ic myelomonocytic leukaemia (1/5), and Philadelphia chromosome-negativ e chronic myeloid leukaemia (1/5), Three out of the five patients demo nstrated an increased proportion of bone marrow ringed sideroblasts. A fter a follow-up period of 30-57 months all patients but one are alive . Idic(X)(q13) always occurred as the sole chromosomal abnormality, ei ther in one or in two copies. We confirmed the dicentric nature of the aberration by fluorescence in situ hybridization (FISH) on metaphases as well as interphase nuclei using an X-chromosome-specific alpha-sat ellite probe, and performed chromosome painting to visualize possible additional chromosomal changes involving the X chromosomes. Our findin gs and the data of 17 previously published cases indicate that idic(X) (q13): (1) may play a significant pathogenetic role in haematological malignancies affecting exclusively females and deriving predominantly from early progenitor cells; (2) is frequently associated with a patho logical iron accumulation; (3) indicates a variable prognosis.