Der(16)t(1;16)(q11;q11) in myelodysplastic syndromes: a new non-random abnormality characterized by cytogenic and fluorescence in situ hybridization studies.

The der(16)t(1;16)(q11;q11) is a frequent recurrent rearrangement in solid tumours such as breast carcinomas and Ewings sarcomas. Recently, this abnormality was described also in multiple myeloma. We identified a der(16)t(1;16)(q11;q11) in three patients with myelodysplastic syndrome, either during preleukaemic phase (n = 2) or at the time of blastic transformation (n = 1).

Der(16)t(1;16)(q10;p10) in multiple myeloma: a new non-random abnormality that is frequently associated with Burkitt's-type translocations.

Aneuploidy is a frequent feature in multiple myeloma. Cytogenetic analyses have shown that a 14q+ chromosome resulting from either a t(8;14)(q24;q32) or a t(11;14)(q13;q32) was the most consistent abnormality but no specific chromosomal aberration has been identified in this disease. Bone marrow cells from 121 consecutive patients with multiple myeloma were analyzed cytogenetically by standard banding techniques including RHG, GTG and CBG banding.

New case of t(3;17)(q26;q22) as an additional change in a Philadelphia-positive chronic myelogenous leukemia in acceleration.

A new case of t(3;17)(q26;q22) was observed in a Philadelphia-positive (Ph+) chronic myelogenous leukemia in acceleration 1 month before occurrence of the blastic phase. Abnormal megakaryocytopoiesis and thrombopenia were noted, but blast cells did not express platelet markers. The same translocation was previously reported in three myeloproliferative disorders in acceleration or in the process of becoming acute.

[X maternal mosaicism and genetic counseling].

Among number of women having consulted for repeated miscarriages about sixty have a gonosomic mosaicism involving chromosome X for which abnormal clones (monosomy and/or excess) are always the minority. A retrospective study of the obstetrical follow up these patients have shown that 23% of them will give birth to a child with a chromosomic abnormality (21 trisomy, 13 trisomy, 45,X, 45,X/46,X iso X (q), 48,XXXX, 49 XXXXXY, del 5 p-). The hypothesis of a tendency toward non-disjunction is pushing for an prenatal diagnosis for patients with X mosaicism.