[Molecular cytogenetic characterization of five patients with myeloid leukemia and t(12;22)(p13;q12)].

OBJECTIVE: To explore the clinical and laboratory characteristics of 5 patients with myeloid leukemia and t(12;22)(p13;q12). METHODS: Bone marrow cells were cultured for 24 h and analyzed by standard R-banding. Rearrangement of the MN1 gene was detected by fluorescence in situ hybridization (FISH) using dual color break-apart MN1 probes. MN1-ETV6 and ETV6-MN1 fusion genes were detected by reverse transcription polymerase chain reaction (RT-PCR). And the products were subjected to direct sequencing. RESULTS: Among the 5 patients, 2 had AML-M0, 2 had AML-M4, and 1 had CMM0L at the initial diagnosis. t(12;22)(p13;q12) was the primary abnormality among all patients. Rearrangements of MN1 gene were detected by FISH in all patients. MN1-ETV6 and ETV6-MN1 fusion genes were detected respectively in 4 and 3 patients. CONCLUSION: t(12;22)(p13;q12) is a rare but recurrent chromosomal abnormality in myeloid leukemia, and is related to poor prognosis. allo-SCT is valuable for patients with t(12;22)(p13;q12).

[Clinical and laboratory features of 13 cases of myeloid neoplasms with double del (20q)].

OBJECTIVE: To report on clinical and laboratory features of myeloid neoplasms with double del(20q). METHODS: Cytogenetic examination of bone marrow was performed on 13 cases of myeloid neophasms with double del(20q) after 24 hours of cell culture. R-banding was used to analyze the karyotypes. Interphase fluorescence in situ hybridization (FISH) was performed using dual-color probes for 20q11/20q12. RESULTS: Double del(20q) was found to be the sole abnormality in 9 cases, double del(20q) and trisomy 9 was found in 1 case, trisomy del(20q) was found in 1 case, and sole del(20q) clone and double del(20q) clone were found to coexist in 2 cases. In 10 cases, interphase FISH showed one green and one red signal in cells with del(20q), which indicated deletion of both 20q11 and 20q12. Immunophenotyping of the leukemia cells showed positiveness for CD13 and/or CD33, CD117 in all 9 cases. Among these, co-expression of CD34 and/or HLA-DR was found in 6 cases, and coexpression of CD3 and CD7 was found in 1 case. Of the 13 cases, there were one AML-M6, nine MDS, one pure amegalokaryocye aplastic thrombocytopenia, one with normal morphology of bone marrow, and one undetermined due to dilution of the bone marrow by blood. Cytopenia were found in all cases. 9 of 13 cases died, and 4 survived with a median survival of 9 months. CONCLUSION: Double del(20q) is a rare but recurrent chromosomal abnormality derived from del(20q). It has unique clinical and laboratory features, and the prognosis is poor.

[Clinical and cytogenetic study of 6 cases of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities].

OBJECTIVE: To analyze clinical and cytogenetic features of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities. METHODS: Following short-term culture of bone marrow cells, karyotypic analysis was carried out with R-banding. 20q- and t(20;21) (q11;q11) was detected by fluorescence in situ hybridization (FISH) using dual-color 20q11/12 probe, ST 20qter /ST 21qter probes, SE20(D20Z1)/SE 13/21 probes, and WC20/WC21 probes. RESULTS: Six (2.3%) of the 257 patients with 20q- detected by conventional karyotypic analysis were found to have t(20;21) (q11;q11) abnormality. Five cases had myelodysplastic syndrome, 1 had acute lymphoblastic leukemia. Above results were all confirmed by FISH. CONCLUSION: i (20q-), t(20;21) (q11;q11) seems to be a rare but recurrent chromosomal abnormality which is specifically associated with myeloid disease, late occurrence and poor prognosis. The translocation between chromosome 20q11 and 21q11 may form a novel fusion gene which has an important role in the pathogenesis of the disease.

[Clinical and experimental study of a multiple myeloma case with low hypodiploidy].

OBJECTIVE: To report the clinical and laboratory characterization of a case of multiple myeloma with low hypodiploid complex karyotyptic abnormalities. METHODS: Cytogenetic examination of bone marrow performed by 24 h culture method. R-banding technique was used to analyze the karyotype. Interphase fluorescence in situ hybridization (FISH) was performed using chromosome probes such as 13q14, p53, Rb1, 1q21 and IgH/CCND1. The DNA content was detected by flow cytometry. RESULTS: Chromosome analysis revealed complex chromosomal rearrangement. Five cells had a low hypodiploid karyotype with 35 chromosomes. Three cells had the duplication of the low hypodiploid karyotype. Four cells had a normal karyotype. Monosomy 1, 13, 14, 17 and a mark chromosome 1 derived from chromosome 11 resulting in the amplication of CCND1 gene were confirmed by interphase FISH. Flow cytometric analysis displayed a low hypodiploid peak with the DNA index of 0.8426. CONCLUSION: These results indicated that the low hypodiploidy is a rare abnormality in multiple myeloma. Interphase FISH is a reliable method for detecting molecular abnormalities in multiple myeloma.

[Fluorescence in situ hybridization study of acute myeloid leukemia with cryptic chromosome rearrangements].

OBJECTIVE: To detect specific chromosome rearrangements in acute myeloid leukemia (AML) using interphase-fluorescence in situ hybridization (FISH). METHODS: All cases were studied by R-band karyotypic analysis using direct method and/or short-term culture for chromosomes preparation. Interphase-FISH was performed in 108 cases of AML with M5, M4, M2, M3 subtypes including 103 cases with normal karyotypes, 4 cases with chromosomal abnormalities other than specific chromosomal rearrangements using chromosome translocation probe such as AML1/ETO, PML/RARα, CBFß/MYH11 and MLL. RESULTS: Of 38 cases of M2-AML without t(8;21) on conventional cytogenetics(CC) analysis, 4 cases showed positivity for AML1/ETO fusion transcript, which included 2 cases with typical signal model and 2 with insertion. Of 9 cases of M3-AML without t(15;17) on CC analysis, 6 showed positivity for PML/RARα fusion transcript including 2 with typical signal model, 3 with insertion, one without PML/RARα rearrangement on reverse transcription-PCR and FISH assay using PML/RARα probe. FISH assay using the RARα dual color, break-apart rearrangement probe indicated a partial deletion of RARα. Of 23 cases with M4 or M4EO-AML without inv(16) on CC analysis, 3 showed positivity for CBFß/MYH11 fusion transcript. Of 38 cases without 11q23 translocation on CC analysis, all cases were negative for MLL rearrangement. CONCLUSION: Interphase-FISH can detect specific chromosome rearrangements such as AML1/ETO, PML/RARα or CBFß/MYH11 in some AML cases with normal karyotype, though it seemed less useful for the detection of MLL rearrangement.

[Chromosome study on chronic lymphocytic leukemia using CpG-oligodeoxynucleotide as immunostimulant agent].

OBJECTIVE: To investigate whether CpG-oligodeoxynucleotide (CpG-ODN) can improve the detection rate of the karyotypic abnormalities in chronic lymphocytic leukemia (CLL). METHODS: The bone marrow (BM) or peripheral blood (PB) cells from 57 cases of CLL were collected and cultured with CpG-ODN DSP30+interleukin-2 (IL-2), phytohemagglutinin (PHA), pokeweed (PWM) or IL-2, respectively. Five days later cells were harvested for chromosome preparation. Karyotypic analysis was done using R banding technique. Panel fluorescence in situ hybridization (FISH) was carried out on 19 cases of CLL with normal karyotypes using the following probes: Cen12, D13S25, Rb1, ATM, p53, MYB and IgH. Genomic DNA from 21 cases of them was extracted from BM or PB leukocytes. The immunoglobulin variable heavy chain (IgVH) was amplified by polymerase chain reaction (PCR) and sequenced. CD38 and ZAP70 expressions in the leukemic cells were determined by flow cytometry (FCM). RESULTS: The detection rate of karyotypic abnormalities in the CpG-ODN+IL-2 group (43.85%) was obviously higher than that in the PHA (15.09%), PWM (17.31%) and IL-2 (3.13%) groups (P<0.01). Fifty-two types of karyotypic abnormalities were found. Among them, trisomy12 (+12) or +12 with other abnormalities were the most common, while translocations were the most frequent structural abnormalities including 3 unbalanced and 11 balanced translocations, among them 7 had rearrangements involving 14q32. Thirteen cases showed one or more abnormalities on FISH including trisomy 12 and p53 deletion each in one case, IgH rearrangement and partial deletion each in one case, 13q14.3 deletion in 11 cases of which 5 cases also had Rb1 deletion, 1 case had Rb1 partial deletion. No case with ATM or MYB deletions was found. PCR detected IgVH mutations in 10/21 cases. FCM showed 10/45 cases were CD38 positive, but 35 /45 were CD38 negative, 11/27 cases expressed ZAP70, but 16/27 did not. Among the 26 cases examined for CD38 and ZAP70 expressions simultaneously, 5 cases were CD38+ZAP70+, 13 were CD38-ZAP70-, 6 were CD38-ZAP70+, and 2 were CD38+ZAP70-, respectively. Statistic analysis showed a correlation between complex karyotype and IgVH without mutation, but no association between karyotype and CD38 or ZAP70 expression was observed. CONCLUSION: CpG-ODN immunostimulation can obviously raise the detection rate of abnormal karyotypes, especially translocations in CLL. FISH is an important complement to conventional karyotypic analysis. The combination of both methods can provide more comprehensive genetic information for CLL.

[Clinical Significance of Common Gene Mutations in 53 Patients with Acute Myeloid Leukemia Harboring 11q23/MLL Rearrangements].

OBJECTIVE: To investigate the clinical significance of AML patients with 11q23/MLL rearrangement, and to evaluate the effect of those mutations on the AML patients. METHODS: 53 cases involving translocations of chromosome 11q23 were identified by chromosome banding analysis. MLL rearrangements were detected by fluorescence in situ hybridization and/or multiplex nested PCR. The samples were screened for mutations in the candidate genes FLT3-ITD, FLT3-TKD, TET2, N-RAS, ASXLI, EZH2, DNMT3, C-Kit, NPM1, WT1, CEBPA by using genomic DNA-PCR and deep-sequencing. RESULTS: 21/53 MLL-rearranged AML cases showed at least one additional chromosomal aberrations. The most common additional aberration was +8. Gene mutations were observed in 23 cases (43.4%) and most cases showed singal mutation. N-RAS mutation was more frequent (8 cases, 15.1%), followed by WT1 mutation in 4 cases (7.5%), FLT3-ITD mutation in 3 cases, ASXL1 mutation in 2 cases, DNMT3A mutation in 2 cases, EZH2 mutation in 1 case, c-Kit17 mutation in 1 case, FLT3-TKD mutation in 1 case, and FLT3-ITD and TKD mutation coexistent in 1 case. No mutation was detected in CEBPA, NPM1, C-KIT8, TET2. Median OS for gene mutated patients was 8.5 months and 13 months for no mutated patients. Median OS for patients who received hematopoietic stem cell transplantation (HSCT) was 22.5 months and 7.5 months for patients who olny received chemotherapy. CONCLUSION: A relatively high mutation frequency is observed in AML patients with 11q23/MLL rearrangements and most cases shows single mutation. The RAS signaling pathway alterations are most common. Gene mutation does not affect the OS of these patients, who show poor prognosis. A significantly higher Hb at initial diagnosis in FLT3 mutated patients is significantly higher than that in FLT3 wild-type cases. Patients who underwent HSCT show a better prognosis than those only received chemotherapy.

[Fluorescence in situ hybridization studies on a myeloid leukemia patient with ins(8;21)(q22;q22.1q22.3)].

OBJECTIVE: To report a case of acute myeloid leukemia (AML) with the insertion (8;21)(q22;q22.1q22.3). A 33-year-old Chinese woman was referred to our hospital. Hematologic data showed WBC 42.7 x 10(9)/L with monocytosis (monocyte counts 7.296 x 10(9)/L). Bone marrow aspirate was hypercellular with 4.5% monoblasts and 7.5% promonocytes. At first she was diagnosed with chronic myelomonocytic leukemia (CMML) according to the FAB criteria. Initially the patient received supportive care only, but her general condition rapidly became worse three months later. The monoblasts and promonocytes in the bone marrow rose to 20.5%. After two cycles of combined chemotherapy she obtained complete remission. METHODS: Chromosome specimens were prepared by short-term culture of bone marrow cells. Karyotype analysis was carried out by R-banding technique. Three fluorescence in situ hybridization (FISH) analyses were performed using AML1-ETO dual color, dual fusion probe, whole chromosome painting 8 and 21 probes, and cen-8 and Tel 21qter probes, respectively. Reverse transcription polymerase chain reaction (RT-PCR) assay for detecting the AML1-ETO fusion transcript was also performed. RESULTS: Conventional cytogenetic analysis showed a karyotype of 46,XX,ins(8;21) (q22;q22.1q22.3)[7]/46,XX[3]. FISH tests confirmed the insertion. RT-PCR analysis detected the AML1-ETO fusion transcript. CONCLUSION: We consider that this patient should be rediagnosed as acute myeloid leukemia according to the criteria proposed by World Health Organization (WHO) and that FISH and RT-PCR play an important role in verification of the ins(8;21).

[Simultaneous presence of ins (15;17),t(2;17;20) and trisomy 8 in a patient with acute promyelocytic leukemia].

OBJECTIVE: To report a rare complex karyotypic abnormalities including ins (15;17),t(2;17;20) and trisomy 8 in a patient with acute promyelocytic leukemia (APL). METHODS: Chromosomes were prepared after 24 h culture of bone marrow cells. R-banding technique was used to analyze the karyotype. Multiplex fluorescence in situ hybridization (M-FISH), chromosome painting using whole chromosome parint (WCP) 2, 15, 17 and 20 and interphase-FISH (I-FISH) using PML-RARa dual-colour dual-fusion translocation probe were performed to ascertain the essence and origin of the abnormal chromosomes detected by conventional karyotypic analysis. RESULTS: Karyotypic analysis revealed a karyotype of 47, XY, 2q-, + 8, 17q+ , 20p+ . M-FISH analysis showed a karyotype of 47, XY, t(2;17;20) (q24;q21;p13), + 8, which was confirmed by chromosome painting. PML-RARa fusion gene which lied in the derivative chromosome 15 was detected by I-FISH suggesting a cryptic insertion (15;17)(q22;q21.1q21.3). CONCLUSION: FISH is a reliable method for characterization of cryptic ins (15;17) and other complex translocations. It should be used in all suspected APL patients lacking t(15;17) by conventional karyotypic analysis.

The impact of early molecular response in children and adolescents with chronic myeloid leukemia treated with imatinib: a single-center study from China.

Chronic myeloid leukemia (CML) is rare among children and adolescents. The early molecular response (EMR) is an important prognostic significance for adult CML patients. This study explored the impact of EMR on the prognosis in 40 children and adolescents with CML-CP treated with imatinib (IM). Our results showed that a high proportion of patients failed to achieve the BCR-ABL1/ABL1 International Scale (IS) ≤ 10% at 3 months. Children with a BCR-ABL1/ABL1 ≤ 10% at 3 months and <1% at 6 months increased the rate of achieving complete cytogenetic response (CCyR) and/or major molecular response (MMR) at 12 months compared to those with BCR-ABL1/ABL1 > 10%. With a median follow-up of 42 months, patients with BCR-ABL1/ABL1 ≤ 10% showed a better 4-year event-free survival (EFS). In summary, achieving BCR-ABL1/ABL1 IS ≤10% at 3 months and <1% at 6 months would increase the possibility of achieving MMR, CCyR at 12 months and had a better 4-year EFS. EMR is a reliable prognosticator for young CML patients treated with IM.

[The study of 4 cases of myeloid neoplasm with t (5;12) (q33;p13) and the literatures review].

OBJECTIVE: To report clinical and laboratory features of 4 cases of myeloid neoplasm with t (5;12) (q33;p13). METHODS: Cytogenetic examination of bone marrow cells obtained from patients was performed by 24 h culture method. R banding technical was used for karyotype analysis. PDGFRß gene rearrangement was detected by FISH using dual color break apart PDGFRß probe. ETV6-PDGFRß fusion genes were detected by multiple-reverse transcription polymerase chain reaction (RT-PCR). Direct sequencing analysis was performed on the PCR products in case 1. Immunophenotype analysis was carried out by flow cytometry. Four cases were treated with imatinib (IM) and followed up. RESULTS: The diagnoses included 3 MPN and 1 AML-M2. The t (5;12) (q33;p13) was a primary abnormality in 3 cases of MPN and a secondary abnormality in 1 case of AML-M2. PDGFRß gene rearrangement and ETV6-PDGFRß fusion genes were detected by FISH and multiple-RT-PCR in 4 cases, respectively. The immunophenotypical analysis of leukemia cells showed positive for CD13, CD33 and CD34. Two cases obtained MMR after the treatment of IM, one case complete hematologic and complete cytogenetic response. ETV6-PDGFRß was negative detected by multiple-RT-PCR after the treatment of IM, but relapsed and died soon in case 4. CONCLUSIONS: The t (5;12) myeloid neoplasm was a subtype with unique features. The t (5;12) maybe a primary chromosome abnormality in MPN and a secondary in AML. MPN with t (5;12) could benefit from IM, but not for AML. Dual-FISH was a reliable tool for detecting PDGFRß rearrangement.

Clinical and molecular cytogenetic studies in ten patients with hematological malignancies characterized by t(20;21)(q11;q11) resulted from del(20q).

This study reports 10 patients with hematological malignances with t(20;21)(q11;q11) resulting from del(20q) (for example, der(20)del(20)(q11q13)t(20;21)(q11;q11) and der(21)t(20;21)(q11;q11)) and described their clinical features and the possible prognostic significance of this abnormality. The t(20;21)(q11;q11) was a rare but recurrent abnormality secondary to del(20q) besides i(20q-). The frequency of der(20)del(20)(q11q13)t(20;21)(q11;q11) among our patients with del(20q) was 2.4%. It was considered that the 20q deletion preceded translocation with chromosome 21. This abnormality is often cryptic, occurs predominantly in older men and is observed most often in myelodysplastic syndromes. Patients with this abnormality have an unfavorable prognosis, similar to patients with i(20q-). The molecular consequences of der(20)del(20)(q11q13)t(20;21)(q11;q11) may be different from patients with i(20q-). To the best of our knowledge this is the largest dataset published to date.

Microarray CGH analysis of hematological patients with del(20q).

Deletion of the long arm of chromosome 20 is a common abnormality underlying hematological malignancy. We analyzed 21 patients with hematologic diseases confirmed to carry the del(20q) by conventional cytogenetics and fluorescence in situ hybridization using microarray comparative genomic hybridization (aCGH). Seventeen patients were positive for del(20q), but this deletion was not detected in four patients. All deletions detected were interstitial of which continuous deletions were seen in 12 patients and discrete deletions in five. Three commonly deleted regions (CDRs) and two commonly retained regions (CRRs) were defined: CDR1 spanning 3.05Mb (34560497-37608229) within 20q11.23, CDR2 spanning 1.76Mb (37851501-39615698) within 20q12, CDR3 spanning 116Kb (48120412-48236791) within 20q13.13, CRR1 spanning 1.1Mb (29374726-30428250) within 20q11.21, and CRR2 spanning 2.5Mb (60484668-62963548) within 20q13.33. Duplications of retained regions (20q11.21) were found in five cases with similar erythroid hyperplasia (2 M6, 3 MDS). Moreover, duplication of 20p13-p11.21 was also found in two cases with M6. Using the CDRs and CRRs, we identified the candidate genes we searched for using the UCSC Genome Browser. Our data suggest that aCGH analysis is useful for more precisely defining breakpoints on 20q. Further work is required to identify candidate pathogenic genes within these CDRs and CRRs.

The characteristics and prognostic analysis in 213 myeloid malignancy patients with del(20q): a report of a single-center case series.

The clinical and hematological characteristics and the prognostic significance of del(20q) were investigated in a consecutive series of 213 myeloid malignancies. In the analyses, the cases were divided into three subgroups according to diagnosis or four subgroups according to cytogenetic data. Patients in the myeloproliferative neoplasms subgroup had high WBCs and platelet counts at initial diagnosis. The del(20q) occurred predominantly in older men. Sole del(20q) was observed most often in myelodysplastic syndromes, while del(20q) as a part of complex karyotypes was observed predominantly in acute myeloid leukemia. The most frequent additional abnormalities accompanying del(20q) were -5/del(5q), -7/del(7q) and +8; t(20;21)(q11;q11) and double del(20q) were two rare but recurrent abnormalities secondary to del(20q). In all types of diseases, patients with a sole del(20q) had a favorable prognosis. The presence of any additional abnormality with del(20q) had an unfavorable outcome. Patients with i(20q) had an unfavorable prognosis. Patients with the minor del(20q) clone had a better median survival than those with the major del(20q) clone.

The utility of fluorescence in situ hybridization analysis in diagnosing myelodysplastic syndromes is limited to cases with karyotype failure.

Fluorescence in situ hybridization (FISH) is being used increasingly in cytogenetic diagnosis of myelodysplastic syndromes (MDS). However, the utility of FISH in this role has not been well-defined. A total of 249 de novo MDS patients were submitted to karyotyping and FISH analysis for -5/del(5)(q31), -7/del(7)(q31), +8, -17/i(17)(q10), del(20)(q12), and -Y. Of the 234 patients with available karyotypic data, 143 cases (60.9%) demonstrated normal karyotype and 91 cases (39.1%) showed abnormal karyotype. FISH confirmed R-banding findings in 96.6% (226/234) of samples with successful karyotyping and detected cytogenetic abnormalities in 46.7% (7/15) of cases with karyotype failure. Of the 3.4% (8/234) patients showing discrepancies between FISH and R-banding, FISH revealed cytogenetic abnormalities in four patients with normal karyotypes and four patients with complex karyotypes. These results highlight FISH analysis has limited value in MDS cases with successful karyotyping and is only informative in MDS cases with karyotype failure.

Y-chromosome loss as the sole karyotypic anomaly with 3'RARalpha submicroscopic deletion in a case of M3r subtype of acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by the presence of a chromosomal rearrangement involving retinoic acid receptor alpha (RARalpha) gene generating the X-RARalpha fusion. We describe here a unique RARalpha gene rearrangement in a patient with M3r subtype of APL. Conventional cytogenetic analysis revealed Y-chromosome loss as the sole karyotypic anomaly. No X-RARalpha fusion was detected by fluorescence in situ hybridization (FISH) using PML/RARalpha dual-color dual-fusion translocation probe set, or RARalpha dual-color break apart rearrangement probe or reverse-transcription polymerase chain reaction (RT-PCR). However, FISH using RARalpha dual-color break apart rearrangement probe showed a deletion of the entire 3'-end of one allele of RARalpha gene. To our knowledge, this is the first documented APL with 3'RARalpha submicroscopic deletion which is not associated with X-RARalpha fusion. The molecular consequences of this anomaly remain to be elucidated.

Translocation (14;14)(q11;q32) with simultaneous involvement of the IGH and CEBPE genes in B-lineage acute lymphoblastic leukemia.

Translocation (14;14)(q11;q32) is one of the recurrent chromosome aberrations in ataxia-teleangiectasia (AT) and T-cell malignancies. In patients with the t(14;14), the TCL1 and TCRalpha/delta genes were found to be involved at the molecular level. However, t(14;14)(q11;q32) is an exceedingly rare phenomenon in B-lineage acute lymphoblastic leukemia (B-ALL). To date, it has been reported in only 5 B-ALL cases. Here, we report another B-ALL case with t(14;14)(q11;q32) in a 39-year-old female. The immunophenotype of the blasts showed positivity for CD79a, CD10, CD19, and HLA-DR. Chromosome analysis of the bone marrow (BM) cells at presentation showed the karyotype 47,XX,+4,t(14;14)(q11;q32). Fluorescence in situ hybridization (FISH) demonstrated trisomy 4 and the simultaneous involvement of the IGH gene at 14q32 and the CEBPE gene at 14q11, which differs from the genes involved in T-cell leukemias. After chemotherapy, the patient achieved complete remission (CR). Later, she received allogeneic peripheral blood stem cell transplantation. After CR, the karyotype of the BM cells was normal. She was disease-free at a 6-month follow-up. We suggest that t(14;14)(q11;q32) involving the IGH and CEBPE genes in B-ALL is rare, but it is a recurrent abnormality that could identify a new subgroup of B-ALL.