t(7;12)(q36;p13), a new recurrent translocation involving ETV6 in infant leukemia

The ETV6 gene is rearranged as a result of translocations involving a wide variety of chromosomal partners. To date, 12 partner genes for ETV6 have been cloned, and a further 23 chromosomal regions have been described. We previously identified a cryptic t(7;12) with ETV6 involvement in two cases of infant leukemia. The finding of a third case of t(7;12), also in an infant, prompted a more focussed search based on the common features found in these patients and those reported in the literature. The selection criteria were age at diagnosis < 20 months and the presence of +19 and/or +8 in the karyotype; cases with abnormalities of 7q and/or 12p were also considered. FISH studies using whole chromosome paints and probes for the ETV6 gene revealed a t(7;12) in 10 out of 23 cases studied. Seven of these had evidence of ETV6 rearrangement. Of those with ETV6 involvement, six had a 7q36 and one a 7q22 breakpoint. Importantly, in three cases the 7q36 breakpoint was within the same PAC, suggesting the existence of a new nonrandom translocation. However, in at least one patient the 7q36 breakpoint was different. The identification of the 7q partner genes will determine whether it is the disruption of ETV6 alone, or the formation of fusion genes, that is important for leukemogenesis in these patients. As both 7q36 and 7q22 are critical regions of gene loss in del(7q) leukemias, the identification of partner genes from these regions may also be important in understanding the pathogenesis of these diseases.     

The t(1; 12)(p36;q13) in a Renal Oncocytoma

A new chromosome rearrangement, t(1;12)(p36;q13). is added to the cytogenetic changes found in renal oncocytomas. The breakpoint in 12q is cytogenetically different from those of the MAR region, and molecularly HMGlC located in 12q 15 on the basis of 3′ RACE experiments does not seem to be directly involved. Genes Chrornosorn Cancer l7:/36–/39 (1996). © 1996 Wiley-Lia, Inc.     

46，XX，t（7；13）（p13；q12）一例

患者女，33岁，因习惯性流产就诊。患者表型、智力均正常，月经正常，妇科检查：子宫、附件正常。外周血染色体分析其核型为：46，Xx，t（7；13）（7qter→7p13：：13q12→13qter；13pte→＋13q12；：7p13→7pter）。其夫核型正常。父母非近亲结婚，其母无不良生育史，其妹流产2次，第3次生育一表型正常男孩。父、母、妹均未作染色体检查。     

Inheritance and phenotypic expression of a t(7;9)(q36;q34)mat

We describe a subtle familial chromosome rearrangement which involves 7q36 and 9q34. The clinical manifestations of 3 apparently balanced individuals with presumed identical translocation breakpoints are presented. In addition, the phenotypes of 2 cytogenetically unbalanced sibs in the same nuclear family are compared.     

Activation of HLXB9 by juxtaposition with MYB via formation of t(6;7)(q23;q36) in an AML-M4 cell line (GDM-1)

Mutation or dysregulation of related homeobox genes occurs in leukemia. Using RT-PCR, we screened members of the EHG family of homeobox genes, comprising EN1 (at 2q14), GBX2 (at 2q36), and EN2, GBX1, and HLXB9 (at 7q36), for dysregulation in acute myeloid leukemia (AML) cell lines indicated by chromosomal breakpoints at these sites. Only one EHG-family gene was expressed, HLXB9, in cell line GDM-1 (AML-M4). Karyotypic analysis of GDM-1 revealed a unique t(6;7)(q23;q35), also present in the patient. Fluorescence in situ hybridization analysis showed chromosomal breakpoints close to the region upstream of HLXB9, at 7q36, a region rearranged in certain AML patients, and at 6q23 upstream of MYB, a gene activated in leukemia. Detailed expression analysis suggested ectopic activation of HLXB9 occurred via juxtaposition with regions upstream of MYB, which was highly expressed in GDM-1. Our data identified a cell line model for a novel leukemic translocation involving MYB with HLXB9, further implicating HLXB9 in leukemogenesis.     

Translocation (2;8)(p12;q24) associated with a cryptic t(12;21)(p13;q22) TEL/AML1 gene rearrangement in a child with acute lymphoblastic leukemia

We report a case of childhood acute lymphoblastic leukemia with the simultaneous occurrence of a t(2;8)(p12;q24) typically associated with mature B cell or Burkitt leukemia, and a t(12;21)(p13;q22) exclusively associated with pre-B cell ALL. The lymphoblasts were characterized as L2 morphology by the French-American-British classification. However, there were atypical morphologic findings for L2 ALL, including vacuolization in some cells. The lymphoblasts were periodic acid-Schiff positive and myeloperoxidase negative. Immunophenotypic analysis revealed that the majority of lymphoblasts were TdT+, CD10+, CD19+, CD20-, and cytoplasmic mu+. These features were consistent with an immature pre-B cell leukemia phenotype with some characteristics of a mature B-cell leukemia. A t(2;8)(p12;q24)(p12;q24), characteristic of mature B-cell leukemia or Burkitt type leukemia, was detected by conventional cytogenetics with no other cytogenetic abnormalities. However, diagnostic peripheral blood and bone marrow specimens demonstrated simultaneous occurrence of a cryptic t(12;21)(p13;q22) by both FISH and RT-PCR. The simultaneous occurrence of these translocations in a pediatric patient have implications for the pathogenesis of leukemias with t(2;8)(p12;q24) as well as t(12;21)(p12;q22). Analysis of additional cases of leukemia with translocations involving the MYC locus on 8q24 will be required to determine the frequency of association with the cryptic t(12;21)(p13;22), and the prognostic significance of the simultaneous occurrence of the translocations.     

t(6;12)(q23;q13) and t(10;16)(q22;p11) in a phyllodes tumor of breast.

Cytogenetic analysis of short-term cultures from a phyllodes tumor showed clonal chromosome changes including t(6;12)(q23;q13) and t(10;16)(q22;p11). This is the first reported karyotype in this tumor type. We discuss the breakpoints of these translocations in relation to the involvement of possible candidate genes.     

Reciprocal translocation t(3;12)(q27;q13) in lipoma

A reciprocal translocation, t(3;12)(q27;q13), was found as the sole karyotypic abnormality in an intramuscular lipoma. The morphology of the derivative 3q+ was strongly reminiscent of the large ring marker we have previously described in three other lipomas, indicating a pathway through which the rings may have arisen. These data, combined with the previous preliminary report by Turc-Carel et al. of a similar t(3;12) in another lipoma strongly suggest that this rearrangement may be a characteristic cytogenetic marker in benign lipogenic tumors.     

t(5;12)(q13;p13) in acute myeloid leukemia with preceding granulocytic sarcoma

A 56-year-old woman was brought to the emergency room with gum swelling and pain. Biopsy of the gingiva revealed sheet-like proliferation of myeloperoxidase and CD45-positive large cells, and she was diagnosed with granulocytic sarcoma. Two years later, bone marrow involvement of granulocytic sarcoma was suspected. Her chromosome study repeatedly revealed a 46,XX,t(5;12)(q13;p13) karyotype. Case reports of t(5;12)(q13;p13) are extremely rare in the literature. To our knowledge, this is the first report of t(5;12)(q13;p13) in a patient with acute myelogenous leukemia with preceding granulocytic sarcoma.     

Nonrandom t(1;22)(p12-p13;q13) in acute megakaryocytic malignant proliferation

A case of acute megakaryocytic leukemia (M7) and one of acute myeloid hemopathy affecting megakaryocytic and erythrocytic cell lineages in infants are reported. Both patients had t(1;22)(p12-p13;q13). This translocation was previously observed in a congenital M7 leukemia. These studies suggest that t(1;22) translocation can be nonrandom in M7.     

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.     

Chromosomal translocation t(1;13)(p36;q14) in a case of rhabdomyosarcoma.

Cytogenetic studies of a rhabdomyosarcoma of mixed embryonal and alveolar histology in an 11-month-old male revealed a single structural abnormality, t(1;13)(p36;q14). This abnormality may define a subset of patients with a variant of the t(2;13)(q35;q14) translocation frequently seen in alveolar rhabdomyosarcoma.     

B-cell lineage acute lymphoblastic leukemia with i(7q) and t(9;9)(p22;p24)

A 61-year-old Japanese male with acute lymphoblastic leukemia (ALL) is reported. Surface marker examinations revealed that the leukemic cells were of a B-cell lineage; the cells had common ALL antigens, Ia-like antigens, and B1 and B4 antigens. Chromosome analysis showed abnormalities of t(9;9)(p22;p24), as well as an isochromosome for the long arm of chromosome 7. The heritable fragile site at 9p was not detected in the peripheral blood cells of this patient at remission phase.     

46,X,t(Y;9)(p11;q12)一例

患者男,30岁,结婚6年,性生活正常,未采取任何避孕措施,至今未孕。双乳房呈正常男性型,外生殖器未见明显异常。一般情况好,外观、表型正常,无面部或肢体的明显不对称,第二性征及外生殖器发育正常。辅助检查:(1)超声检查:右侧睾丸大小39mm×22mm×30mm,体积14.2mL,左侧睾丸39.7mm×29.3mm×19.9mm,体积12.1mL,双侧睾丸大小形态正常,左侧精索静脉轻度曲张。(2)精液分析:精液总量为4.0mL,pH7.5,液化时间30min,精子密度:106/mL,活动率22.43%,其中a级为2.8%、b级为5.61%、c级14.02%、d级77.57%,畸形率为78%。(3)细胞遗传学分析:染色体检查核型为…