Spontaneous expression of fra(11)(q23) in a patient with Ewing's sarcoma and t(11;22)(q23;q11)

Cytogenetic analysis of a Ewing's sarcoma revealed a 46,XX,t(8;18)(q11;q21.3), t(11;22)(q23–24;q11–12) chromosome pattern. Observation of t(11;22) is consistent with other reported cases of Ewing's sarcoma. One breakpoint in this translocation, 11q23, coincides with the location of a folate-sensitive fragile site. Examination of peripheral blood leukocyte chromosomes from the patient revealed a 46,XX chromosome pattern with spontaneous, fluorodeoxyuridine-, and Bactrim-induced expression of fra(11)(q23). This may be the first demonstration of constitutional fra(11)(q23) expression in a patient with a neoplasm that exhibits a chromosome rearrangement involving this breakpoint and the first observation of spontaneous expression of this fragile site. These results provide a basis for discussion of the relationship between fragile sites and chromosome rearrangements.     

The 11q23 breakpoint in acute leukemia with t(11;19)(q23;p13) is distal to those of t(4;11), t(6;11) and t(9;11).

Thirteen cosmid probes were mapped on the long arm of chromosome 11 between 11q22 and 11q24 by nonradioactive in situ hybridization. Starting with these localizations and those of other probes mapped to 11q23, four acute leukemias with translocations involving 11q23 were studied with the same method. The translocation breakpoints of the t(4;11)(q21;q23), t(6;11)(q27;q23), t(9;11)(p21-p22;q23), and t(11;19)(q23;p13) were confirmed to be distal to CD3D. The probe cC111-304 was proximal to the t(11;19) breakpoint while distal to the breakpoints of the other rearrangements. In view of the diversity of chromosomal abnormalities involving band 11q23, our finding extends the molecular heterogeneity of the breakpoint localization in leukemias with rearrangements involving 11q23.     

Regions of genomic instability on 22q11 and 11q23 as the etiology for the recurrent constitutional t(11;22)

The constitutional t(11;22)(q23;q11) is the only known recurrent, non-Robertsonian translocation. To analyze the genomic structure of the breakpoint, we have cloned the junction fragments from the der(11) and der(22) of a t(11;22) balanced carrier. On chromosome 11 the translocation occurs within a short, palindromic AT-rich region (ATRR). Likewise, the breakpoint on chromosome 22 has been localized within an ATRR that is part of a larger palindrome. Interestingly, the 22q11 breakpoint falls within one of the 'unclonable' gaps in the genomic sequence. Further, a sequenced chromosome 11 BAC clone, spanning the t(11;22) breakpoint in 11q23, is deleted within the palindromic ATRR, suggesting instability of this region in bacterial clones. Several unrelated t(11;22) families demonstrate similar breakpoints on both chromosomes, indicating that their translocations are within the same palindrome. It is likely that the palindromic ATRRs produce unstable DNA structures in 22q11 and 11q23 that are responsible for the recurrent t(11;22) translocation.     

Cytogenetic changes at 11q11, 11q23, and 17q11 in myelodysplastic syndrome

Cytogenetic studies were performed on two patients with myelodysplastic syndromes. One patient was a 68 year old Japanese male in whose bone marrow cells two translocations were established, i.e., t(4;11)(q13;q23) and t(11;17)(q11?;q11), as well as other karyotypic changes (-6,-18,15p+). The other patient was a 74 year old white male whose bone marrow cells showed six marker chromosomes, i.e., der(5),t(5;17)(q12;q11), der(6),t(6;5)(q27;q22), der(8),t(8;11;?)(q11;q11----q23;?), der(11),t(11;?)(q11;?), an isochromosome of the long arm of chromosome #8, and a small G-group sized marker chromosome of unknown origin. Though the translocation patterns in the abnormal cells in these two cases were different, the breakpoints of the marker chromosomes were almost the same, i.e., 11q11, 11q23, and 17q11. Also, changes of chromosome #6 were observed; the first case showed monosomy 6 and the second a 6q+ marker chromosome. In these two cases of myelodysplastic syndromes, common sites of chromosome breakage and reunion of 11q23 and 17q11 were close to recently established sites of human cellular oncogene homologs, c-ets (11q23) and c-erbA (17q21----24). These associations draw attention to a possible relationship between chromosome changes in myelodysplastic syndromes and oncogene (or other gene) activation and/or dysfunction.     

Chromosomes in Ewing's sarcoma. II. Nonrandom additional changes, trisomy 8 and der(16)t(1;16)

Chromosomal data from 82 informative, unrelated Ewing's sarcoma (ES) specimens (including 20 personal specimens) were reviewed for secondary changes additional to the t(11;22)(q24;q12). Additional numerical and/or structural changes were found in 75 specimens. Trisomy 8 was observed consistently in half of the 43 cases selected for analysis of numerical changes. A nonrandom der(16) was observed as a result of an unbalanced t(1;16) in 18% of the 82 analyzed for structural changes. Consistent involvement of chromosome #16 in rearrangements with chromosome #1 may be an additional chromosome change specifically associated with ES.     

A complex genetic rearrangement in a t(10;14)(q24;q11) associated with T-cell acute lymphoblastic leukemia.

The t(10;14)(q24;q11) is observed in the leukemia cells of 5-10% of cases of T-cell acute lymphoblastic leukemia (T-ALL). Recently, molecular analyses of a number of these translocations revealed simple reciprocal translocations between the T-cell receptor delta chain gene (TCRD) and a region of 10q24. We have characterized, at the molecular level, a t(10;14)(q24;q11) in a patient with T-ALL. The translocation in this case, in contrast to the previous cases, is part of a complex genetic rearrangement. In addition to a reciprocal translocation between the D delta 3 gene segment of TCRD and a region of 10q24, a local inversion occurred within TCRD, involving the D delta 2 and V delta 2 gene segments. As a consequence, the entire joining and constant regions and most of the diversity regions of TCRD are located on the derivative 14 chromosome, whereas the joining and constant regions of TCRA are positioned on the derivative 10 chromosome. The chromosome 10 breakpoint in our patient, as in other t(10;14), clusters within a 9 kb breakpoint region. The occurrence of seven breakpoints within a localized region of chromosome 10 implies the existence of a nearby gene whose activation may have conferred a selective advantage on the leukemia cells. Moreover, as in the previous cases, the translocation in the present study exhibits recombination signal sequences or signal-like sequences adjacent to the breakpoint junction. The presence of such motifs suggests the involvement of the recombinase enzyme system in the generation of this genetic alteration.     

Unbalanced translocation der(11)t(11;12)(q23;q13): a new recurrent cytogenetic aberration in myelodysplastic syndrome with a complex karyotype

Cytogenetic abnormalities are observed in approximately one half of cases of myelodysplastic syndrome (MDS). Partial or complete chromosome losses and chromosome gains are frequently found, but there is a relatively high incidence of unbalanced translocations in MDS. We describe here two cases of MDS with an unbalanced translocation, der(11)t(11;12)(q23;q13). Both patients were 69 years of age and diagnosed with refractory anemia with excess of blasts in transformation (RAEB-t) according to the high percentage of blasts in the peripheral blood. Cytoplasmic hypogranulation of neutrophils was evident as a dysplastic change. The blasts were positive for CD4 and CD41a as well as CD13, CD33, CD34 and HLA-DR in both cases. Chromosome analysis showed complex karyotypes including a der(11)t(1;11)(q11;p15)t(11;12)(q23;q13) in case 1 and der(11)t(11;12)(q23;q13) in case 2 plus several marker chromosomes. Spectral karyotyping confirmed the der(11)t(11; 12)(q23;q13) and clarified the origin of marker chromosomes, resulting in del(5q) and del(7q). Fluorescence in situ hybridization (FISH) analyses with a probe for the MLL gene demonstrated that the breakpoints at 11q23 were telomeric to the MLL gene in both cases. FISH also showed that the breakpoint at 11p15 of the case 1 was telomeric to the NUP98 gene. Considering another reported case, our results indicate that the der(11)t(11;12)(q23;q13) is a recurrent cytogenetic abnormality and may be involved in the pathogenesis of advanced-stage MDS.     

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.     

Philadelphia chromosome (Ph) positive chronic myelocytic leukemia (CML): frequency of additional findings

This article documents the cytogenetic findings in 79 patients with typical Ph-positive chronic myelocytic leukemia (CML). Direct preparations of bone marrow and/or peripheral blood of 46 males and 33 females were studied with different banding techniques. Seventy patients were studied during chronic phase. Three (4.3%) had unusual or complex translocations: t(6;22)(p21;q11), t(8;12;9;22)(p21;q21;q34;q11), and t(9;11;22)(q34;q13;q11). One (1.4%) had a +Ph, 1 (1.4%) had a +8, 1 (1.4%) had a del(3)(p13,p23), and 4 of 30 males (13.3%) showed loss of Y chromosome. Five of 8 cases studied during blast crisis had additional abnormalities. The +8 occurred in 4 cases, +10 and +19 each in 3 cases, +6, + 9q+, and +13 each in 2 cases, and +5, +11, +14, +21, +Ph, i(17q), dic(1;9), and structural abnormalities of chromosomes #1, #5, #12, and #13 each in 1 case. Two cases studied in blast crisis alone had complex translocations leading to the Ph. Because it cannot be ruled out that these translocations are secondary, they were not included in the calculation of the frequency of atypical translocations.     

Translocation (5;10)(q22;q24) in a case of acute lymphoblastic leukemia

The activation of genes important to acute lymphoblastic leukemia (ALL) may be evidenced by somatically acquired chromosomal translocations found recurrently in different patient subgroups. It is for this reason that research efforts have focused on the molecular dissection of recurring chromosomal rearrangements. However, even though a large number of leukemia-causing genes have been identified, the genetic basis of many ALL cases remains unknown. We and others have reasoned that novel translocations found in the leukemic cells of ALL patients may mark the location of more frequent gene rearrangements that are otherwise hidden submicroscopically within normal or complex karyotypes. Towards this end, we here describe the first reported association of a t(5;10)(q22;q24) with adult ALL. Fluorescence in situ hybridization (FISH) and Southern blot hybridization studies have eliminated likely involvement of the candidate genes APC and MCC on chromosome 5, and PAX2, TLX1, and NFKB2 on chromosome 10. Results further suggest that the breakpoint on chromosome 5 lies centromeric of APC and the chromosome 10 breakpoint is centromeric of PAX2. The genomic regions disrupted by this t(5;10)(q22;q24) have not previously been associated with leukemia.     

Variant Ph translocations in chronic myeloid leukemia

Variant translocations were found in eight of 142 consecutive patients with Ph-positive, chronic myeloid leukemia encountered in our laboratory during the last decade. Two patients had simple, two-way variant translocations: t(17;22)(p13;q11) and t(16;22)(q24;q11). Both of these patients had an additional translocation involving chromosomes #9: t(7;9)(q22;q34) and t(9;17)(q34;q21), respectively. Complex variant translocations were found in four cases: t(2;9;22)(p23q12;q34;q11), t(3;9;22)(p21;q34;q11), t(9;12;22)(q34;q13;q11q13), and t(13;17;22)(p11;p11q21;q11). In two cases, the only discernable cytogenetic aberration was del(22)(q11). A review of the chromosomal breakpoints involved in this series and in 185 cases of variant Ph translocations previously reported in the literature reveals that a disproportionately large number of breakpoints are located in light-staining regions of G-banded chromosomes. Furthermore, the breakpoints in simple variant translocations are more often located in terminal chromosomal regions, whereas, the breakpoints in complex translocations typically affect nonterminal bands. No obvious correlation was detected between variant Ph translocation breakpoints and either fragile sites, oncogene locations, or consistent chromosome breakpoints in other malignancies.     

Multiple karyotypic rearrangements, including t(X;18)(p11;q11), in a fibrosarcoma

The tumor stem line of a soft tissue fibrosarcoma, histologic malignancy grade III, had 43 chromosomes with several clonal chromosome aberrations, including the three balanced translocations t(X;18)(p11;q11), t(2;15)(p23;q26), and t(7;22)(q11;q13), two partly identifiable marker chromosomes, der(3)dic(3;?)(p11;?) and der(5), one small marker of unknown origin, and loss of one chromosome #11, #18, #19, and #21.     

Nonrandom cytogenetic changes in leiomyomas of the female genitourinary tract. A report of 35 cases

Cytogenetic analysis of short-term cultures from 35 leiomyomas of the female genitourinary tract showed abnormal karyotypes in 14 cases. In 11 of 14 aberrant tumors, normal cells were also observed. Structural changes were most frequent, resulting in modal chromosome numbers in the diploid range. Our data confirm preferential breakpoint clusters at 7q, 12q14-15, and 14q23-24, mainly resulting from consistent, specific chromosome rearrangements such as t(12;14)(q14-15;q23-24) and del(7)(q21) or del(7)(q22q32). Together with previously published cases, we describe trisomy 12, ring chromosomes, and monosomy 22 as new additional recurrent findings in myomas. Statistical analyses of possible coherencies between tumor karyotype (abnormal versus normal) and clinicopathologic data, as well as age of the patients, menopausal status, and tumor size showed no correlations.     

Multicolor spectral karyotyping of serous ovarian adenocarcinoma.

We applied multicolor spectral karyotyping (SKY) to decipher the chromosomal complexity of a panel of seven cell lines and four primary tumors derived from patients with high‐grade serous adenocarcinoma of the ovary. By this method we identified a total of 188 unbalanced translocations, nine reciprocal translocations [t(2;15)(q13;q23), t(7;17) (q32;q21), t(8;22)(p11;q11), t(8;22) (q24;q13), t(10;19) (q24;q13.2), t(11;19) (q13;p11), t(12;21)(q13;q22),t(18;20) (q?11;q?11), t(18;22)(q?11;q?13)], 6 isochromosomes [i(1q), i(7q), i(8q), i(9p), i(17q), i(21q)], and 23 deletions. By detailed mapping of rearrangement breakpoints, it was possible to identify several recurring breakpoint clusters at chromosomal bands 1p36, 2p11, 2p23, 3p21, 3q21, 4p11, 6q11, 8p11, 9q34, 10p11, 11p11, 11q13, 12p13, 12q13, 17q21, 18p11, 18q11, 20q11, and 21q22. Recurrent interstitial deletion of chromosomal bands 8p11, 11p11, and 12q13 and a recurrent unbalanced translocation—der(6)t(6;8)(q11;q11)—were also identified. In addition, a homogeneously staining region localized in one cell line to 11q13 was found using SKY to be derived from genetic material originating from chromosome 12. Subsequent comparative genomic hybridization (CGH) studies on this tumor revealed the amplification of DNA sequences derived from the short arm of chromosome 12 at the 12p11.2 region. These studies demonstrate the power of SKY, CGH, and G‐banding to resolve the full spectrum of chromosomal rearrangements in serous ovarian adenocarcinoma. © 2002 Wiley‐Liss, Inc.     

Two new chromosomal abnormalities in chronic myelogenous leukemia 46,XY,t(9;15;22)(q34;q22;q11) and 46,XY,t(6;9;12;22)(p21;q34;q24;q11)

Two new variant cases of chronic myelogenous leukemia (CML) are presented. The first case is a 19-year-old male with a 46,XY,t(9;15;22)(q34;q22;q11) karyotype. The second case is a 75-year-old man with a 46,XY,t(6;9;12;22)(p21;q34;q24;q11) karyotype. In both cases, the prognosis was no different from those cases of CML with the standard t(9;22) as the only abnormality. We recommend that all unusual translocations be reported.     

Myeloid- and lymphoid-specific breakpoint cluster regions in chromosome band 13q14 in acute leukemia.

Abnormalities of chromosome band 13q14 occur in hematologic malignancies of all lineages and at all stages of differentiation. Unlike other chromosomal translocations, which are usually specific for a given lineage, the chromosomal translocation t(12;13)(p12;q14) has been observed in both B-cell and T-cell precursor acute lymphoblastic leukemia (BCP-, TCP-ALL), in differentiated and undifferentiated acute myeloblastic leukemia (AML), and in chronic myeloid leukemia (CML) at progression to blast crisis. The nature of these translocations and their pathologic consequences remain unknown. To begin to define the gene(s) involved on chromosome 13, we have performed fluorescence in situ hybridization (FISH) using a panel of YACs from the region, on a series of 10 cases of acute leukemia with t(12;13)(p12;q14) and 1 case each with "variant" translocations including t(12;13)(q21;q14), t(10;13)(q24;q14) and t(9;13)(p21;q14). In 8/13 cases/cell lines, the 13q14 break fell within a single 1.4 Mb CEPH MegaYAC. This YAC fell immediately telomeric of the forkhead (FKHR) gene, which is disrupted in the t(2;13)(q35;q14) seen in pediatric alveolar rhabdomyosarcoma. Seven of the 8 cases with breaks in this YAC were AML. In 4/13 cases, the 13q14 break fell within a 1.7-Mb YAC located about 3 Mb telomeric of the retinoblastoma (RB1) gene: all 4 cases were ALL. One case of myelodysplastic syndrome exhibited a break within 13q12, adjacent to the BRCA2 gene. These data indicate the presence of myeloid- and lymphoid-specific breakpoint cluster regions within chromosome band 13q14 in acute leukemia.     

High resolution banding of chronic myeloid leukemia chromosomes

Bone marrow aspirates from 29 patients with chronic myeloid leukemia were studied using the methotrexate synchronization culture method. Successful cytogenetic preparations exhibiting long and well banded chromosomes were obtained from all of them. The standard t(9;22) was seen in 23 patients, four had variant translocations, and two were Ph-negative. Of the four patients with variant translocations, one had a simple translocation in which the missing segment of chromosome #22 was translocated onto the short arm of chromosome #9. The remaining three patients had complex translocations. The first involved chromosomes #11, #19, and #22, the second involved chromosomes #9, #11, and #22, and the third involved chromosomes #9, #14, and #22. Karyotypic abnormalities in addition to the Ph chromosome were seen in four patients: in three these changes developed during the chronic phase and in one during the blastic phase. Using Q-, R-, and G-banding techniques, we found that the breakpoint on chromosome #22 is just below the centromere, namely in band 22q11.2 and on chromosome #9 in band 9q34.1. The standard translocation, therefore, can be written as t(9;22)(q34.1;q11.2). Furthermore, the breakpoint on 22q appeared to be identical in all cases with standard as well as the variant translocations. Our results show that the methotrexate synchronization method permits consistent high resolution banding of CML chromosomes, and support the concept that there is no difference in the amount of material translocated from 22q in different patients.     

Transposition of breakpoint cluster region (3' bcr) in CML cells with variant Philadelphia translocations

A probe derived from the 3' end of the CML breakpoint cluster region (bcr) was localized in chronic myelocytic leukemia (CML) cases with complex Philadelphia translocations, [t(8;9;22)(q13;q34;q11) and t(12;9;22)(p11;q34;q11)], and with "masked" Ph chromosomes, [t(9;5;22)(q34;q31;q11) and t(9;22)(q22;q34)], by a chromosomal in situ hybridization technique. In some cases, the 3' bcr rearrangements in the DNA were examined with Southern blot analysis. In each case, a significant accumulation of grains hybridized to the 3' bcr probe was observed at chromosomal segments derived from the long arm of a chromosome #22. In some cases, the accumulation of grains was detected on both translocated segments derived from the 22q and terminal portions of Ph chromosomes; Southern blot analysis revealed that breakage in chromosome #22 occurred within DNA sequences of the 3' bcr probe involved in the Ph translocations. In a CML cell line, K562, no accumulation of grains hybridized to the 3' bcr probe was detected, except at 22q11 of the normal chromosomes #22; Southern blot analysis of this cell line revealed that the 3' bcr sequences were missing. Thus, the data presented here suggest a complexity in the formation of "masked" Ph chromosomes.     

Cytogenetic and molecular cytogenetic studies of a variant of t(21;22), ins(22;21)(q12;q21q22), with a deletion of the 3' EWSR1 gene in a patient with Ewing sarcoma

Ewing sarcoma is the second most common malignant bone tumor in children and young adults. Cytogenetic analysis to identify a common t(11;22)(q23;q12) or less frequently a t(21;22)(q22;q12) or t(7;22)(p22;q12) plays an important role in the confirmation of the clinical diagnosis. We report a case of a 10-year-old female who had extraskeletal Ewing sarcoma. Conventional cytogenetic analysis revealed that 11 out of 20 cells had a derivative chromosome 22, possibly due to an insertion of the long arm of the 21q21 approximately q22. This finding was confirmed by fluorescence in situ hybridization (FISH) utilizing whole chromosome paint probes specific for chromosomes 21 and 22. Hybridization utilizing LSI EWSR1, dual-color break-apart rearrangement probe unexpectedly revealed that the 3' EWSR1 gene was lost on the derivative chromosome 22. This finding suggests that the insertion of chromosome 21 is another mechanism that could lead to EWS-ERG gene fusion. To our knowledge, this is the first case report of an insertion of a segment of 21q21 approximately q22 into the long arm of 21q12 with a loss of a DNA segment around the breakpoint on the derivative chromosome 22 in Ewing sarcoma.     

T-cell acute lymphoblastic leukemia with translocation (1;18)

A case of T-cell acute lymphoblastic leukemia with a translocation between chromosomes #1 and #18 is described. The breakpoints were at bands 1q23 and 18q21. A single cell contained the translocation t(1;19)(q23;p13). The breakpoint on chromosome #1 was the same in both translocations, and the breakpoint on chromosome #18 was the same as that in t(14;18)(q32;q21) associated with follicular lymphoma. The possible relationship between chromosome bands 1q23 and 18q21 and the morphologic features of the leukemia cells is discussed.