Translocation t(12;22)(q13;q13) is a nonrandom rearrangement in clear cell sarcoma.

Cytogenetic analyses of tumor cells from a case of clear cell sarcoma revealed a translocation between chromosomes 12 and 22 that was similar to the rearrangement described recently in three other cases. It is suggested that the translocation may be important in the pathogenesis of this rare tumor.     

t(12;22)(q13;q13) and trisomy 8 are nonrandom aberrations in clear-cell sarcoma.

We report a case of clear-cell sarcoma with a t(12;22)(q13;q13) and multiple copies of chromosome 8 in addition to other abnormalities. An identical or similar translocation has previously been reported in this type of tumor, suggesting that the t(12;22) is a primary cytogenetic change in the pathogenesis of a subset of clear-cell sarcomas. In addition, the presence of extra copies of chromosome 8, commonly noted in our case and others, suggests that it represents a nonrandom secondary change in these tumors.     

t(11;18)(q21;q21) is a recurrent chromosome abnormality in small lymphocytic lymphoma.

We have identified two cases of previously untreated, small lymphocytic lymphoma with extranodal involvement, which had a reciprocal translocation, t(11;18)(q21;q21), as the sole cytogenetic abnormality. These two cases are remarkably similar to two previously reported cases carrying this translocation with regard to clinical features, cytogenetic abnormality, histologic subtype, and immunophenotype. Molecular genetic analysis of these two cases revealed clonal gene rearrangement of the IGH locus but only germline configuration of the BCL2 oncogene at 18q21 when probes and conditions that usually identify BCL2 rearrangement in lymphomas were used. Lymphomas bearing an (11;18) rearrangement appear to make up a phenotypically identifiable subgroup. Identification of the genes at the translocation breakpoints will be important.     

Is t(6;20)(p21;q13) a characteristic chromosome change in endometrial polyps?

Cytogenetic analysis of an endometrial polyp showed the presence of a t(6;20)(p21;q13) together with an ins(16;1)(q22;q32q42). Since a 6;20-translocation has been previously found in another endometrial polyp, we think that t(6;20)(p21;q13) may be a characteristic chromosomal change in endometrial polyps.     

Translocation t(11;21)(q24;q11.2) is a new nonrandomly occurring chromosome change in myelodysplastic syndromes

An identical translocation, t(11;21)(q24;q11.2), has been observed in three patients with a myelodysplastic syndrome. In all cases, duplication of the 11q+ marker and loss of the normal chromosome 11 were observed either at diagnosis or during the evolution of the disease. This apparently characteristic chromosome abnormality has not been previously described.     

Translocation (10;17)(p15;q21) is a recurrent anomaly in acute myeloblastic leukemia

We report here two cases of patients with acute myeloblastic leukemia, type M1 (FAB classification), associated with a t(10;17)(p15;q21). Fluorescence in situ hybridization with the LSI PML/RARA dual-color probe showed the breakpoint to be distal to the RARA locus. Four other patients with this translocation have been reported, three of them having acute undifferentiated or poorly differentiated leukemia.     

Translocation t(13;17)(q12-14;p12-13) in two patients with lymphocytic lymphoma

Cytogenetic studies were performed at the time of diagnosis on two patients with diffuse small cell lymphocytic lymphoma. Both patients had a similar simple karyotype with a t(13;17)(q12-14;p12-13). These observations confirm the nonrandom involvement of band 13q13 in chronic lymphoproliferative diseases.     

Intravenous leiomyomatosis is characterized by a der(14)t(12;14)(q15;q24)

Intravenous leiomyomatosis (IVL) is a rare smooth-muscle proliferation that is of special interest because of its quasi-malignant behavior. Our finding of a specific chromosomal aberration, a der(14)t(12;14)(q15;q24), in a second case of IVL suggests that it may be characteristic of IVL. We propose that IVL arises from a uterine leiomyoma with a t(12;14)(q15;q24). The presence of an extra copy of 12q15-qter and/or loss of 14q24-qter may be a critical genetic event(s) leading to intravascular intrusion and proliferation.     

Recurrent trisomy 15 in a female carrier of der(15)t(Y;15)(q12;p13)

We report on a female carrier of der(15) t(Y;15)(q12;p13) who had two pregnancy losses with trisomy 15 and one with tetraploidy. Molecular analysis showed that both non-disjunction events resulting in the trisomy 15 pregnancies occurred in maternal meiosis I. This finding raises the possibility that there may be an increased risk for trisomy 15 in some carriers of unbalanced t(Y;15) which, if followed by trisomic zygote rescue, may lead to uniparental disomy (UPD).     

A novel der(12)t(7;12)(p15;q24.3) in a patient with childhood T-cell acute lymphoblastic leukemia

Approximately 35% of T-cell acute lymphoblastic leukemia (T-ALL) cases have chromosomal translocations as evaluated by conventional cytogenetic methods (G-banding). Some chromosomal translocations are associated with morphologically and immunophenotypically distinct leukemia subtypes and define patients with different clinical outcomes. Chromosomal translocations may deregulate gene expression, thus contributing to the development of neoplasia, either by placing a putative oncogene under the control of strong regulatory elements or by generating chimeric genes and oncogenic fusion proteins. We report here a novel der(12)t(7;12)(p15;q24.3) in a child with T-ALL. Cloning and characterization of the breakpoint region may contribute to the discovery of new genes that are important in T-ALL.     

Acute leukemia with t(1;3)(p36;q21), evolution to t(1;3)(p36;q21), t(14;17)(q32;q21), and loss of red cell A and Le(b) antigens.

At transformation of refractory anemia with ring sideroblasts to acute nonlymphocytic leukemia (ANLL) the bone marrow cells of a 75-year-old woman showed three different karyotypes, i.e., 46,XX,46,XX,t(1;3)(p36;q21) and 46,XX,t(1;3)(p36;q21),t(14;17)(q32;q21). She received no antileukemic therapy, and 1 year later, all her bone marrow cells were t(1;3)(p36;q21),t(14;17)(q32;q21). In association with the onset and first 11 months of ANLL, the platelet count increased 10-fold to a peak of 750 x 10(9)/L, providing further evidence that the t(1;3)(p36;q21) translocation causes stimulation of thrombopoiesis. Six months after transformation, her red cells showed reduced expression of A and Leb antigens. Serum alpha-n-3-acetylgalactosaminyl transferase (blood group A transferase) and red cell adenylate kinase were both reduced. The genes for both these substances are at 9q34, which suggests an abnormality here, although cytogenetically chromosome 9 appeared normal. This is the first case with t(1;3)(p36;q21) to show concurrent loss of red cell antigens and the first report detailing the course of untreated ANLL with t(1;3)(p36;q21).     

Pediatric acute myeloid leukemia with t(7;21)(p22;q22)

The t(7;21)(p22;q22) resulting in RUNX1‐USP42 fusion, is a rare but recurrent cytogenetic abnormality associated with acute myeloid leukemia (AML) and myelodysplastic syndromes. The prognostic significance of this translocation has not been well established due to the limited number of patients. Herein, we report three pediatric AML patients with t(7;21)(p22;q22). All three patients presented with pancytopenia or leukopenia at diagnosis, accompanied by abnormal immunophenotypic expression of CD7 and CD56 on leukemic blasts. One patient had t(7;21)(p22;q22) as the sole abnormality, whereas the other two patients had additional numerical and structural aberrations including loss of 5q material. Fluorescence in situ hybridization analysis on interphase cells or sequential examination of metaphases showed the RUNX1 rearrangement and confirmed translocation 7;21. Genomic SNP microarray analysis, performed on DNA extracted from the bone marrow from the patient with isolated t(7;21)(p22;q22), showed a 32.2 Mb copy neutral loss of heterozygosity (cnLOH) within the short arm of chromosome 11. After 2‐4 cycles of chemotherapy, all three patients underwent allogeneic hematopoietic stem cell transplantation (HSCT). One patient died due to complications related to viral reactivation and graft‐versus‐host disease. The other two patients achieved complete remission after HSCT. Our data displayed the accompanying cytogenetic abnormalities including del(5q) and cnLOH of 11p, the frequent pathological features shared with other reported cases, and clinical outcome in pediatric AML patients with t(7;21)(p22;q22). The heterogeneity in AML harboring similar cytogenetic alterations may be attributed to additional uncovered genetic lesions.     

Identification of a yeast artificial chromosome spanning the 8q12 translocation breakpoint in pleomorphic adenomas with t(3;8)(p21;q12)

A subgroup of pleomorphic adenomas of the salivary glands is characterized by translocations involving chromosome 8, with consistent breakpoints at 8q12. As part of a positional cloning effort to isolate the gene(s) affected by these translocations we now report the mapping of the 8q12 breakpoint in two primary pleomorphic adenomas with the recurrent t(3;8)(p21;q12). Yeast artificial chromosome (YAC) clones corresponding to eight different loci in 8q11-12 were isolated and mapped by fluorescence in situ hybridization (FISH). The t(3;8) breakpoint was mapped within a 1 Mb region flanked by MOS proximally and by the genetic marker D8S166 distally. One YAC within this region was shown to span the t(3;8) breakpoint in two tumors. This YAC will provide an excellent tool for isolating the gene(s) at the breakpoint(s) in adenomas with t(3;8). Genes Chromosom Cancer 17:166–171 (1996). © 1996 Wiley-Liss, Inc.