Clinical Significance of Common Gene Mutations in 53 Patients with Acute Myeloid Leukemia Harboring 11q23/MLL Rearrangements / 中国实验血液学杂志

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.

Clinical and cytogenetic study of 6 cases of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze clinical and cytogenetic features of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Clinical and experimental study of a multiple myeloma case with low hypodiploidy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To report the clinical and laboratory characterization of a case of multiple myeloma with low hypodiploid complex karyotyptic abnormalities.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Fluorescence in situ hybridization study of acute myeloid leukemia with cryptic chromosome rearrangements / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect specific chromosome rearrangements in acute myeloid leukemia (AML) using interphase-fluorescence in situ hybridization (FISH).</p><p><b>METHODS</b>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, CBFβ/MYH11 and MLL.</p><p><b>RESULTS</b>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 CBFβ/MYH11 fusion transcript. Of 38 cases without 11q23 translocation on CC analysis, all cases were negative for MLL rearrangement.</p><p><b>CONCLUSION</b>Interphase-FISH can detect specific chromosome rearrangements such as AML1/ETO, PML/RARα or CBFβ/MYH11 in some AML cases with normal karyotype, though it seemed less useful for the detection of MLL rearrangement.</p>

Fluorescence in situ hybridization studies on a myeloid leukemia patient with ins(8;21)(q22;q22.1q22.3) / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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).</p>