Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 24-year-old man with Philadelphia-chromosome (Ph)-negative chronic myelocytic leukemia (CML) developed lymphoid blast crisis. In the chronic phase, karyotype was normal and the clinical and hematological features were indistinguishable from those of Ph-positive CML. Rearrangement of the breakpoint cluster region (bcr) was observed. In the blast phase, blast cells showed early B-cell phenotype (CALLA+, Ia+, TdT+) with a rearranged immunoglobulin heavy-chain gene joining region (JH). By using an immunoblotting method and antiphosphotyrosine sera, P210bcr-abl protein was detected. The patient responded well to vincristine and prednisolone (VP) therapy. These findings support the concept that Ph-negative bcr+ CML can behave in a very similar fashion to Ph-positive CML, not only in the clinical features of the chronic phase but also in the manner of the blast crisis.
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PMID:Lymphoid blast crisis in a patient with Philadelphia-chromosome-negative chronic myelocytic leukemia. 249 64

The Philadelphia chromosome of chronic myelogenous leukemia (CML) patients is caused by a translocation of the c-abl gene from chromosome 9 to the breakpoint cluster region (bcr) on chromosome 22. A new bcr-abl mRNA is expressed in these cases. We have developed a modified polymerase chain reaction (PCR) for the detection of this mRNA. The method is extremely sensitive, reliable, and relatively fast. The analysis of peripheral blood or bone marrow cells from CML patients treated with chemotherapy shows that the two possible mRNAs are expressed in various combinations. Our results show that even after myeloablative therapy for bone marrow transplantation bcr-abl mRNAs are still expressed. Further studies, however, are necessary to determine the clinical relevance of a small number of persisting cells expressing the bcr-abl mRNA.
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PMID:Detection by enzymatic amplification of bcr-abl mRNA in peripheral blood and bone marrow cells of patients with chronic myelogenous leukemia. 249 73

The Philadelphia (Ph1) chromosome results in a fusion of portions of the BCR gene from chromosome 22 and the ABL gene from chromosome 9, producing a chimeric BCR-ABL mRNA and protein. In lymphoblastic leukemias, there are two molecular subtypes of the Ph1 chromosome, one with a rearrangement of the breakpoint cluster region (bcr) of the BCR gene, producing the same 8.5-kilobase BCR-ABL fusion mRNA seen in chronic myelogenous leukemia (CML), and the other, without a bcr rearrangement, producing a 7.0-kilobase BCR-ABL fusion mRNA that is seen only in acute lymphoblastic leukemia (ALL). We studied the molecular subtype of the Ph1 chromosome in 11 cases of Ph1-positive ALL, including 2 with a previous diagnosis of CML, using a sensitive method to analyze the mRNA species based on the polymerase chain reaction (PCR). We observed unexpected heterogeneity in BCR-ABL mRNA in this population; in particular, 1 of 6 bcr-rearranged cases and 1 of 5 bcr-unrearranged cases contained none of the known fusion mRNA species, while 1 of the bcr-rearranged cases contained both. This latter case is particularly interesting because it suggests that the acquisition of an additional BCR-ABL fusion species may be a mechanism of disease progression. We conclude that the PCR gives additional information about the Ph1 chromosome gene products that cannot be obtained by genomic analysis, but that it cannot be used as the sole means of detection of this chromosomal abnormality in ALL because of the high incidence of false negative results.
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PMID:Unexpected heterogeneity of BCR-ABL fusion mRNA detected by polymerase chain reaction in Philadelphia chromosome-positive acute lymphoblastic leukemia. 249 81

The remission state of 13 Philadelphia positive chronic myeloid leukemia patients was studied after bone marrow transplantation (BMT) by cytogenetic and Southern blot analysis of the breakpoint cluster region (BCR) gene. Eight of 13 patients showed neither clinical nor genetic evidence of residual disease. In two patients hematological relapse was confirmed by cytogenetic and molecular analysis. Evidence for residual leukemic cells in otherwise complete remission was obtained genetically in three patients. One of the latter cases revealed BCR rearrangement despite negative cytogenetic findings, while in another patient cytogenetic relapse was observed without demonstrable rearrangement within the major BCR. Our results may indicate that cytogenetic and molecular genetic methods complement rather than replace each other for the detection of residual CML cells after BMT.
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PMID:Evaluation of remission state in chronic myeloid leukemia patients after bone marrow transplantation using cytogenetic and molecular genetic approaches. 250 80

A 26-year-old man, who presented with bilateral fundal haemorrhages, was found to have chronic myeloid leukaemia (CML). The Ph chromosome was not present but a clone with t(1;9) (p32;q34) was detected. On referral for bone marrow transplant (BMT) he was found to be in accelerated phase with clonal evolution in three cell lines inv(3)(q21q26); inv(3)(q),i(17q); inv(3q)+8. Molecular investigation revealed a breakpoint on chromosome 22 within the breakpoint cluster region (bcr) similar to that found in Ph+ cases. After BMT, from an HLA-identical sister, successful engraftment (46,XX) was accompanied by evidence of a residual host cell population with further evolution (del(7)(q22)) and persistence of the bcr+ clone. Acute myeloid leukaemia, detected 5 months later, was associated with predominance of the clone 46XY,t(1;9),inv(3q),del(7)(q22) which failed to respond to treatment and the patient died 6.5 months after BMT. This case indicates that BMT, after the acquisition of additional chromosomal change in accelerated phase, may fail owing to persistence of the leukaemic clone. In addition the BMT conditioning regimen may produce further abnormalities which confer drug resistance on the persisting clone, which can emerge as an intractable myeloid blast crisis.
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PMID:Clonal evolution in Ph-negative, bcr-positive chronic myeloid leukaemia before and after bone marrow transplantation. 251 23

A 60-year-old woman presented with diffuse lymphadenopathy. Diagnostic and staging work-up showed that the patient had diffuse small cleaved cell lymphoma (diffuse poorly differentiated lymphocytic lymphoma) with associated histiocytes (lymphoepithelioid cell lymphoma) by the Kiel classification system. Immunohistologic staining showed a T suppressor cell tumour phenotype. Cytogenetic studies revealed the Philadelphia chromosome (Ph1). On DNA studies, the breakpoint cluster region (BCR) gene was not rearranged suggesting that the Ph1 involvement was not identical to that seen in chronic myelogenous leukemia (CML). This case is presented because of the rarity of Ph1 in lymphoid malignancies, particularly in those of T-cell origin, and because of its potentially adverse implications.
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PMID:Philadelphia chromosome without breakpoint cluster region rearrangement in a case of Lennert's lymphoma of suppressor phenotype. 252 33

We report a case of blast crisis in chronic myelogenous leukemia (CML) in which T lymphocytic and megakaryocytic lineages were both involved. A 55-year-old male was initially admitted to Ehime University Hospital because of generalized lymphadenopathy. The morphological features of peripheral blood and bone marrow were consistent with chronic phase of CML. Cytogenetic studies of bone marrow and lymph node cells both showed the Ph1 chromosome with additional abnormalities. The patient was diagnosed as being in the extramedullary blast crisis of CML involving lymph nodes. After six months, blasts increased in bone marrow and peripheral blood. The phenotypes of lymph node blasts were positive for CD2, CD7 and TdT, but negative for CDw41 (platelet glycoprotein IIb/IIIa). On the other hand, those of peripheral blood blasts were positive for CDw41, but negative for CD2, CD7 and TdT. Chromosome studies of lymph node cells and bone marrow cells revealed 46, XY, inv(7) (p15q34), t(9;22) (q34;q11) and 46, XY, t(1;3) (q23:q21), t(9;22) (q34;q11), respectively. The rearrangement of T cell receptor beta chain gene was detected in lymph node blasts, but not in peripheral blood blasts. The identity of the rearrangement patterns of the breakpoint cluster region on chromosome 22 was detected in these blasts. According to these data, it was suggested that blast crisis of CML occurred in two distinct lineages, T lymphocyte and megakaryocyte.
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PMID:A case of chronic myelogenous leukemia with T lymphoblastic and megakaryoblastic mixed crisis. 254 79

Dual rearrangement of immunoglobulin and T-cell antigen receptor (beta, delta) genes was demonstrated in a case of Philadelphia chromosome-positive chronic myeloid leukemia (CML) in blast crisis. The blast cells, showing L2 morphology and high activity of TdT, expressed pre-B cell (CD19+, Ia+) and myeloid (CD13+, CD34+) surface antigens but lacket T-cell antigens (CD2-, CD7-). Cytogenetic studies on bone marrow and peripheral blood revealed the Phl chromosome in all metaphases analyzed, majority of which also had the additional chromosome changes, +8, +10, +21. Furthermore, molecular analysis of the breakpoint cluster region (bcr) on chromosome 22 showed a rearrangement, confirming the CML origin of the blast cells.
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PMID:Dual rearrangement of immunoglobulin and T-cell receptor genes in blast crisis of CML. 254 92

Molecular studies have demonstrated that the Philadelphia chromosome (Ph) translocation characteristic of chronic granulocytic leukemia (CGL) and 50% of the cases of Ph positive acute lymphocytic leukemia (ALL) involves a limited 5.8 Kb region on chromosome 22 termed the breakpoint cluster region (bcr). Detection of bcr rearrangement by Southern blot analysis has proven to be a sensitive diagnostic method and can identify this translocation in some cases which appear cytogenetically negative. Restriction fragment length polymorphisms (RFLP) which involve bcr have the potential to be misinterpreted as gene rearrangements since they result in alteration of the DNA fragment size detected by Southern blot hybridization. We have identified a RFLP involving bcr that is detectable with Eco RI digestion but not with Bam HI, BgI II, or Xba I. The polymorphic fragments generated indicate that this RFLP is the result of an Eco RI restriction site sequence polymorphism.
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PMID:bcr rearrangement: potential false positive secondary to an Eco RI restriction fragment length polymorphism. 257 Aug 95

The human BCR gene on chromosome 22 is specifically involved in the Philadelphia translocation, t(9;22), a chromosomal rearrangement present in the leukemic cells of patients with chronic myeloid leukemia or acute lymphoblastic leukemia. In most cases, the breakpoints on chromosome 22 are found within a 5.8 kb region of DNA designated the major breakpoint cluster region (Mbcr) of the BCR gene. Hybridization experiments have indicated that the human genome contains BCR gene-related sequences. Here we report the molecular cloning of one of these loci, for which we propose the name ABR. In contrast with the other BCR-related genes studied to date, ABR represents a functionally active gene and contains exons very similar to those found within the Mbcr. Unlike the BCR gene, the ABR gene exhibits great genomic variability caused by two different variable tandem repeat regions located in two introns. All other BCR gene-related sequences isolated so far and the BCR gene itself are located on chromosome 22. In contrast, the ABR gene is located on chromosome 17p.
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PMID:ABR, an active BCR-related gene. 258 17


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