Aberrations of chromosome No. 1 in blastic phase of chronic myeloid leukemia

Partial trisomy 1q in idiopathic myelofibrosis

Three cases of idiopathic myelofibrosis with partial trisomy of the long arm of chromosome 1 are described. Partial trisomy 1q was the only karyotypic change detectable in unstimulated peripheral blood cell cultures of one and bone-marrow cultures of two patients at diagnosis. The extra segment from chromosome 1 was located on different karyotype sites, i.e. 1qter, 1p34 and 6p22-23; 1q21-32 was the shortest overlapping region and the only trisomic segment in one of the three patients. These findings suggest that partial trisomy 1q is a primary chromosome aberration in myelofibrosis relevant in the pathogenesis of this hematologic disorder.

Abnormalities of chromosome 1 in relation to human malignant diseases

Chromosome 1 is known to often be involved in various malignant diseases. Its numerical and structural aberrations have been observed in chronic and acute leukemias and solid tumors as well. Recently five protooncogenes have been assigned to the long and short arms of chromosome 1. The frequent and nonspecific occurrence of chromosome 1 rearrangements in human tumors suggests that they play an important role in the pathogenesis and progression of these diseases. The frequency, types, and time of the occurrence of chromosome 1 aberrations and their relation to the stage of the disease were studied in 317 patients with various malignant diseases. In ten patients nonrandom aberrations of chromosome 1 were observed. Two patients had CML, two PRV followed by ANLL, and the remaining six patients suffered from ANLL, ALL, Burkitt lymphoma, MF, SMMoL, and IRSA, respectively. In six patients, total or partial trisomy of the long arm or of the whole chromosome 1 was present, and in three cases balanced translocations involving chromosome 1 could be found. In the cells of one patient a duplication of the centromeric heterochromatin was seen. We analyzed the breakpoints involved. Finally, the aberrations of chromosome 1 were almost always be observed at the terminal stage of the diseases.

Translocation t(8;14)(q24;q32) and del(1)(p22) in FAB-L1 adult acute lymphoblastic leukemia with long survival

Clonal chromosome changes were found in a patient with FAB-L1 acute lymphoblastic leukemia. The changes consisted of a t(8;14)(q24;q32), Burkitt type, and a rare marker chromosome 1p-. The breakpoint in this chromosome was localized at band 1p22. Both these abnormalities were present in 100% of unstimulated peripheral blood cells. The detection of the t(8;14) in a case of acute lymphoblastic leukemia, without a clear evidence of B immunophenotype and with an unusual long survival (more than 3 years), is discussed.

Philadelphia chromosome-positive acute leukemia: morphologic and clinical correlations

Twenty-eight adult patients with Philadelphia chromosome positive (Ph+) acute leukemia were studied to determine if additional chromosomal changes were related to specific morphologic and clinical features. Twenty patients had chronic myeloid leukemia in blast crisis (CML-BC), three had Ph+ de novo acute nonlymphocytic leukemia (ANLL), and five had de novo acute lymphoblastic leukemia (ALL). Chromosomal abnormalities in addition to a single Ph were noted in 90% of patients with CML-BC and included a second Ph (five patients), +8 or duplication of part of 8q (five patients), dicentric isochromosome 17 (two patients), and +19 (two patients). Octaploidy with 4 Ph was seen in one patient with megakaryoblastic transformation. One of two patients with a progranulocytic blast crisis had a t(15;17) abnormality. Hypodiploidy was noted in 4 of 20 patients with CML-BC. Each of the four patients had prominent extramedullary manifestations of blast crisis. All had received intensive chemotherapy prior to the detection of hypodiploidy, and the cytogenetic findings were similar to those often seen in patients with therapy-related leukemia. An inv(3)(q21q26) was noted in two patients (one CML-BC, one de novo Ph+ ANLL), one of whom had hypolobulated micromegakaryocytes. Additional cytogenetic abnormalities in de novo Ph+ ANLL (especially +19) were similar to those in CML-BC. In contrast, the additional karyotypic changes in de novo Ph+ ALL (eg, +4, -7, -20, markers) were those commonly seen in ALL without a Ph and were generally different from those seen in CML-BC.

Genomic diversity of Philadelphia-positive chronic myelogenous leukemia

The incidence of breakpoints in CML patients with variant translocations was investigated. There was no relationship between the length of various chromosomes with breakpoint frequency. However, a significantly higher (p less than 0.05) incidence of breaks were seen on the long arms as compared to the short arms due mainly to the involvement of 9q and 22q in these translocations. Chromosome 17 showed a significantly (p less than 0.005) higher involvement in these translocations, however only when 9q34-qter was not cytogenetically involved. A total of 683 breaks were found in 225 cases. 362 of these were located at c-abl and c-sis, while 110 were at other oncogenetic sites. The prognostic and hematologic features of patients with variant translocations are not significantly different from those of CML cases with the typical 9q;22q translocation. Some of these complex translocation, where the breakpoints are correlated with oncogenetic sites, are further discussed in molecular terms.

Trisomy 1q in polycythemia vera and its relation to disease transition

Clinical and cytogenetic details of 12 patients with polycythemia vera and complete or partial trisomy of the long arm of chromosome 1 are reported. All patients had trisomy for at least the segments 1q22 to 1qter. The 1q or material from 1q was translocated to another chromosome in eight patients. This was chromosome 9 in four patients, and those cases all had trisomy also for 9p. The trisomy 1q was found at the time of diagnosis in three patients, later during the polycythemic phase in five, and in four patients when they were first examined during a late stage of the disease. Acute leukemia or a myelodysplastic syndrome developed in eight of the 12 patients. Signs of advanced disease, eg, myeloid metaplasia or myelofibrosis, preceded the leukemia in four cases and was noted in one more patient. Trisomy 1q was the most frequent structural chromosome abnormality in patients with polycythemia vera. It is thus one of several nonrandom abnormalities that can appear at any stage of the disease. It seems to occur with higher frequency in patients with myelofibrosis and/or leukemia, but it is not a specific characteristic of these complications.

Chromosome 1 aberrations in cancer

Evidence for chromosome #1 involvement in structural rearrangements in cancer is reviewed. There have been adequate studies of cancer at most of the common sites, and at all of these, nonrandom chromosome #1 involvement has been demonstrated. In general, a variety of changes is encountered, irrespective of the site; most commonly, however, the changes result in the duplication of long arm material. It seems that these nonrandom changes, which tend to occur at a relatively late stage, may contribute to the progression of all forms of cancer. However, a small number of chromosome #1 aberrations are also now known, which may represent specific and possibly initiating changes in particular forms of cancer. These include short arm deletions in neuroblastoma and translocations in leukemias and myelodysplasia.

Translocation (1;17) in accelerating and blast phases of chronic myelogenous leukemia

A translocation (1;17)(p11;q11) has been observed in two chronic myelogenous leukemia (CML) patients studied during the accelerated or acute stages of their diseases. In a review of the literature, four additional cases of t(1;17)(p11;q11) were identified, suggesting that this marker may be specific for the terminal phase of CML.

Translocation 1;7 in hematologic disorders: a brief review of 22 cases

A translocation t(1;7)(p11;p11), previously reported in patients with myelodysplasia or leukemia has been found in seven new cases. The present report briefly reviews the cytogenetic and clinical features of 22 patients with this translocation. The majority of these patients had a history of occupational or therapeutic exposure to toxic substances or radiation. Trisomy 8 or 21 were the most common additional abnormalities, especially in leukemic patients. The t(1;7) should be added to the group of specific cytogenetic abnormalities observed frequently in secondary myelodysplasia and leukemia.

Inherited aplastic anemia with abnormal clones in bone marrow and increased endoreduplication in peripheral lymphocytes

Cytogenetic studies in peripheral blood and bone marrow cells from a female patient (aged 31 years) with inherited aplastic anemia and without other congenital anomalies are reported. Endoreduplication was increased in stimulated peripheral lymphocytes in several investigations. Chromosome breaks were shown to be near the control frequency, although chromatid exchange figures and dicentrics were present. Cytogenetic analysis was extended to the three children of our patient. Abnormal clones were detected in bone marrow preparations of our patient in all cytogenetic investigations. At the first examination, two of these clones were prevalent, with their karyotypes being 48,XX, +9, +16 and 46,XX,dup(1)(q24----q32),t(17;?)(p12-13;?). The prevailing karyotype after 2 years was 46,XX,t(17;?)(p12-13;?). Involvement of chromosomes #1 and #17 is discussed, taking into account data from the literature concerning several human neoplasias.

Translocation 1;7 in dyshematopoiesis: possibly induced with a nonrandom geographic distribution

Eight patients with various hematologic disorders had an identical chromosomal aberration in their bone marrow or unstimulated peripheral blood, a translocation t(1;7) interpreted as t(1;7)(p11;p11). The translocation chromosome replaced one normal chromosome #7; therefore, the karyotype of the abnormal cells was trisomic for 1q and monosomic for 7q. Including four cases from the literature, a total of 12 patients (4 women, 8 men) with this translocation are known at the moment. The translocation does not seem to be associated with a specific disorder, but almost all patients had a preleukemic syndrome during some stage of their disease. It is very remarkable that 11 of the 12 patients lived in the Netherlands, and 7 patients had a history of iatrogenic exposure to alkylating agents or irradiation; one patient was a radiation worker and another one had a history of toxic exposure to chloramphenicol. It is suggested, therefore, that the t(1;7) is a possibly induced chromosomal aberration with a clearly nonrandom geographic distribution.

Coexistence of cells with unmasked and masked Ph1 in a case of chronic myeloid leukemia in blastic phase

Bone marrow from a patient with chronic myeloid leukemia in blastic phase at diagnosis showed cells with t(9;22), as well as others with a 22q+ marker. The marker was due to t(8;22), and consequently, these cells presented a masked Ph1: t(8;9;22) (q24.2;q34;q11). The marrow contained a wide variety of abnormal clones, which formed an evolutionary pedigree. The pedigree allowed location of the stage of evolution at which masking of the Ph1 had taken place.

Complete or partial trisomy for the long arm of chromosome 1 in patients with various hematologic malignancies

This study contains data obtained from a cytogenetic investigation of six patients with acute and chronic leukaemia. The karyotypes of bone marrow or blood cells of these patients showed a partial or complete trisomy for the long arm of chromosome 1. Three observations revealed a pronounced resistance of cell clones with 1q+ towards cytostatic therapy, and a comparatively short life span of patients after detection of 1q+. The importance of these changes for the role of some chromosomes and chromosome loci in leukaemogenesis is discussed.

Translocation t(8;22) in peripheral lymphocytes and established lymphoid cell lines from a patient with Hodgkin's disease followed by acute lymphatic leukemia

Cytogenetic studies on primary material and established cell lines of a patient with B-cell non-Hodgkin Lymphoma with leukemic presentation as secondary malignancy after Hodgkin's disease clearly revealed correspondent marker chromosomes in both culture systems. A translocation t(8;22) which has been described in some cases of non-endemic Burkitt's lymphoma as a variant of the translocation t(8;14) was found in all metaphases of the cell lines and in most of the cells of the primary material. In addition, structural aberrations involving chromosomes 1, 2, 3 and 11, as well as numerical deviations concerning chromosomes 2, 4, 7 and Y, could be observed. The cytogenetical findings are discussed in relation to clinical, immunological and cytochemical data.

Chromosomal, morphological and clinical correlations in blastic crisis of chronic myeloid leukaemia: a study of 69 cases

The karyotypic pattern in 69 patients with Ph1-positive chronic myeloid leukaemia (CML) was investigated during the blastic phase (BC) and correlated with survival and certain parameters of potential prognostic significance, including blast morphology, basophilia and thrombocytopenia. There was no difference in median survival in BC between patients with and without aberrations in addition to the Ph1. Nor were there any differences in this respect among patients with the specific aberrations +Ph1, +8, iso(17q), or other abnormalities. There was no correlation between the incidence of thrombocytopenia and any particular karyotypic change. However, the incidence of basophilia was a characteristic feature for patients with an iso(17q). The survival time in BC was considerably longer in patients with a lymphoid morphology of the blastic cells compared to the myeloid varieties, and within the myeloid varieties the survival in BC was longer in patients with granular differentiated blasts than in those with granular atypical blast cells. No obvious correlation was apparent between blast morphology and karyotypic pattern. However, a pattern was discernible regarding survival and certain chromosomal changes within some morphologic groups: in patients with granular differentiated and lymphoid morphology, the median survival in BC was considerably longer when the bone marrow cells had a Ph1 as the sle abnormality compared to patients who had additional aberrations.

Cytogenetic studies in 56 cases with Ph1-positive hematologic disorders

Karyotypes were examined in 56 cases of Ph1-positive hematologic disorders based on direct examination of bone marrow material and culture of blood for 24 hr without phytohemagglutinin (PHA). Various banding techniques (Q, followed by R or C, where necessary) were used. The series of patients consisted of 21 females and 35 males with the ages ranging from 3 to 72 years. In three cases, the clinical and hematologic picture at the time of diagnosis and karyotyping was not compatible with chronic myeloid leukemia (CML): 1 case had acute myeloblastic leukemia (AML), another acute lymphoblastic leukemia (ALL) and the third subacute myeloid leucosis. The results are as follows: In three cases (two female, one male), no Ph1 translocation could be demonstrated in any of the metaphases either with Q- or R-banding. In 50 cases (19 female, 31 male), a standard Ph1 translocation, t(9;22)(q34;q11), was observed. In two of these cases, ages 45 and 47, the Ph1 translocation was accompanied by loss of the Y chromosome in all the metaphases examined. Finally, in three cases (all male), variant Ph1-translocations were found: t(7;9)(9;22)(q35?;q31?;q11), and t(1;9)(9;22)(q21;134;q11).

Cytogenetic studies on four cases of non-endemic Burkitt lymphoma

Cytogenetic studies carried out on four children with non-endemic Burkitt lymphoma showed: 1) Two with the typical translocation t(8;14)(q24;q23); 2) one with a variant t(2;8)(p11;q24); and 3) one with apparently normal chromosomes 8 and 14. Additional chromosomal variation was present in all four patients. Two were shown to have a duplication of part of the long arm of chromosome 1 (1q23 leads to 1q32 and 1q23 leads to 1q42). Epstein Barr virus studies on two patients showed that one was positive and the other negative. A comparison of these results with other non-endemic cases in the literature has been made revealing a wider range of chromosomal variation than has been hitherto reported for endemic cases. The finding that chromosome 8 is also involved in the variant translocations in Burkitt lymphoma suggests that its changes may contribute more to the tumour development than the than the 14q+.

Chromosome pattern, occupation, and clinical features in patients with acute nonlymphocytic leukemia

Chromosome banding pattern of bone marrow cells, cell morphology according to the FAB classification, and clinical finding were compared in two groups of adult patients with acute nonlymphocytic leukemia (ANLL): 52 patients occupationally exposed to chemical solvents, insecticides, or petrol products, and 110 patients with no history of occupational exposure to potential mutagenic/carcinogenic agents. Striking differences were found between the two groups: (1) Clonal chromosomal aberrations were present in 75% of exposed patients compared with only 32% in the nonexposed group. (2) Of the patients exposed to solvents and insecticides 92% had abnormal chromosomes, whereas only 29% of patients exposed to petrol products showed abnormalities; in the total material 10/13 exposed patients with normal chromosomes were exposed to petrol products. (3) The relationship between chromosomal abnormality and exposure was evident in both females and males. However, only 29% of women with an abnormal karyotype were exposed, whereas 70% of males with an abnormal karyotype were exposed. (4) The incidence of certain characteristic karyotypic abnormalities, i.e., -5/5q-, 7/7q-, +8, +21, t(8;21), and t(9;22), were decidedly more common in exposed than in nonexposed patients. At least one of these changes were present in 92% of exposed patients with aberrations, whereas in the nonexposed group the incidence was only 60%. (5) The monocytic varieties of ANLL (M4 + M5) were more common in the nonexposed patients, whereas erythroleukemia (M6) was more common in the exposed group. The predominance of abnormal karyotypes in the exposed compared to the nonexposed patients was similar in leukemia types M1 + M2 and in M4 + M5. (6) There was no difference in survival time between the two groups and the same correlation was obvious in both exposed and nonexposed patients: patients who had only abnormal metaphases had poorer prognosis than those with normal bone marrow metaphases only (6 vs 1.5 months). This correlation was obvious in patients classified as acute myeloid leukemia (AML) as well as in the monocytic varieties of ANLL.

Break points in chromosome #1 abnormalities of 218 human neoplasms

A survey of 343 break points that lead to chromosome #1 abnormalities in 218 human neoplasms showed that 49.9% were located in or immediately adjacent to the centromeric heterochromatin. Amongst rearrangements with breaks in bands p 12-q21 were 27 isochromosomes, 22 translocations of the long arm, and four translocations of the short arm to the heterochromatic regions of other chromosomes, and 35 deletions resulting in chromosomes consisting mainly or solely of one arm. Deletions following breakage at various sites in the short arm of chromosome #1 are frequent in malignancies and are quite often found in cells that are trisomic for the long arm. It is suggested that fragility of chromosomes generated as a result of early events in carcinogenesis may be one source of chromosome rearrangements, including those of chromosome #1, on which selection can operate and give rise to progressively more malignant clones.

De novo duplication 1q32-q42: variability of phenotypic features in partial lq trisomics

A de novo tandem duplication 1q32--q42 was observed in a 7-month-old mentally retarded and malformed male infant. Karyotype-phenotype correlation in other similar unbalanced trisomies has shown psychomotor retardation, micro- or retrognathia or both, and low set or malpositioned ears to be the most common features associated with this newly recognised syndrome. However, after reviewing patients with duplication of regions 1q2, 3, and 4 and 1q2 and 3, it was concluded that similar non-specific clinical features are also present in these 1q imbalances. On the whole, a rather wide range in phenotypical expression has been observed in different cases. Thus it is concluded that, at present, it is impossible to delineate the profile of the syndromes resulting from partial 1q trisomies.