Cytogenetic studies in 112 cases of untreated myelodysplastic syndromes.

Cytogenetic studies were performed in 112 untreated cases of myelodysplastic syndrome (MDS) between 1985 and 1990. Among 112 patients who were examined at the time of diagnosis, 54 had an abnormal karyotype (48%). The highest frequency of chromosome abnormalities was observed in refractory anemia with excess of blasts (RAEB) and RAEB in transformation (RAEB-t) and the lowest in refractory anemia with ring sideroblasts (RARS) and chronic myelomonocytic leukemia (CMMoL). Numerical changes were observed in 19 cases and structural in 17; chromosome 8 was most frequently gained (11 cases), whereas chromosome 7 was most frequently lost (6 cases), 5q- in 14 (4 as a sole anomaly); involvement of 7q22 was seen in 3 cases, 11p in 2 patients, 11q in 3 (one patient as a sole anomaly), 12p in 4 (2 patients as a sole anomaly), i(17q) in 4 (3 patients as a sole anomaly), and complex chromosomal defects in 10 patients. If one takes into account the prognosis value, a complex karyotype and the presence of ring chromosomes were correlated with the worst prognosis, followed by -7/7q-; an intermediate prognosis corresponds to i(17q), 12p as a sole anomaly, +8 (as a sole anomaly or plus other anomalies), and involvement of 12p. Patients with a 5q- as a sole anomaly or with a normal karyotype, had the best prognosis.     

Chromosome 11 abnormalities in myelodysplastic syndromes.

Cytogenetic studies were performed in 140 patients with myelodysplastic syndrome (MDS) at diagnosis. Chromosome 11 anomalies were found in 7 cases (5%); 2 of these patients had refractory anemia (RA), 2 had refractory anemia with excess of blasts (RAEB), 1 had RAEB in transformation (RAEB-t), and 2 had chronic myelomonocytic leukemia (CMMoL) according to the French-American-British (FAB) Cooperative Group criteria. The chromosome 11 abnormalities comprised trisomy 11 (2 patients), monosomy 11 (1 patient), del(11)(q23) (2 patients), add(11)(p15) (1 patient), and der(11) t(3;11)(p21;q23) (1 patient). Abnormalities involving band q23 of chromosome 11 occurred in 3 cases and were the most common alteration. However, specific chromosomal alterations were not associated with any FAB classification group. These findings and their implications in the biology of MDS are discussed.     

Clinical-cytogenetic correlations in myelodysplasia (preleukemia)

Cytogenetic studies detected abnormalities in 107 (43%) of the 247 patients in this series. Some degree of overt clinical progression occurred in 55 patients (22%), this being 29% of those patients with cytogenetic abnormalities and 17% of those with normal chromosomes. The presence and complexity of a clonal cytogenetic abnormality correlated with shorter survival. In each clone category of a complexity classification (simple, complex, very complex), patients with some normal cells appeared to have better survival than those with none. In multiple regression analyses, the prognostic value of chromosomes was independent of (and second in importance to) the FAB type of myelodysplastic syndrome (MDS) whichever chromosome classification was used. Patients with refractory anemia (RA) had the lowest incidence of chromosome abnormalities and no cases were found to have only abnormal cells (AA). A greater proportion of patients with refractory anemia with an excess of blasts (RAEB) and RAEB in transformation (RAEB-t) had clonal abnormalities. Morphology alone is not at present able to distinguish between RA or refractory anemia with ringed sideroblasts and similar disorders that may not be MDS in the strict sense. Demonstration of a clonal cytogenetic abnormality remains a positive indication of the presence of the neoplastic nature of the disease.     

Proliferative indices, cytogenetics, immunophenotye and other prognostic parameters in myelodysplastic syndromes

Thirty-five adult myelodysplastic syndrome (MDS) patients were included in this study: 11 refractory anemia (RA), 4 RA with ring sideroblasts (RARS), 9 RA with excess of blasts (RAEB), 10 RAEB in transformation (RAEB-T) and 1 chronic myelomonocytic leukemia (CMML). The ranges of survival were 4-51 months, 40-59 months, 7-38 months, 5-24 months and 5 days, respectively. Three patients died and 3 showed disease progression during the course of the study. A composite analysis of proliferative indices, cytogenetics, immunophenotype and other conventional/novel prognostic parameters in the context of Indian MDS patients was performed. The proliferative indices (AgNOR and Ki 67 positivity), immunophenotypic markers, serum LDH and ferritin levels revealed wide variations and great overlap among different FAB subtypes. The scoring systems (Bournemouth, Dusseldorf and Goasguen) did not correlate with the prognosis and survival (p > 0.05). Clonal cytogenetic abnormalities were detected in 24/35 (68.57%) patients, +8, -5 and -7 being observed commonly. Cytogenetic abnormalities were more frequent in RAEB (88.8%), RAEB-T (80.0%) and RA (63.6%) subtypes of MDS. By Using Mufti's prognostic system and International prognostic scoring system (IPSS), a good positive correlation was found between low risk category and RARS with better survival as compared to other risk categories/FAB subtypes (p < 0.01). However, rest of the FAB subtypes were assigned into high, intermediate and low risk categories without any correlation with the survival and/or leukemic transformation. RARS subtype revealed itself as the better prognostic category according to the cytogenetic findings as well as Mufti's grading system. This was possible due to the longer follow up available for these patients (40-59 months).     

Translocation (3;21) characterizes crises in myeloid stem cell disorders.

Three patients, one with Philadelphia (Ph) chromosome positive chronic myelocytic leukemia (CML) and two with primary acquired myelodysplastic syndromes (MDS), have been identified to have a t(3;21)(q26;q22). In the patient with CML, the t(3;21) was detected only in the blast phase. The t(3;21) as the sole abnormality appeared at presentation of MDS [refractory anemia with excess blasts (RAEB)] in one patient and remained as such when progression to RAEB in transformation (RAEB-t) occurred. The other patient with MDS had the t(3;21), in addition to other changes, during the progression of the disease. Thus, t(3;21) may characterize myeloid crises of clonal hematopoietic stem cell disorders (HSCD) and indicates a poor prognosis. As a primary cytogenetic event it may be also involved in the genesis of myelodysplasia with subsequent leukemic transformation.     

Chromosome abnormalities in myelodysplastic syndrome

We performed chromosomal analysis in 18 patients with myelodysplastic syndrome (MDS). According to the French-American-British (FAB) cooperative study group and Research Group of Japanese Ministry of Welfare Classification, our cases with MDS were classified into four subtypes as follows; refractory anemia [RA], 6 cases; refractory anemia with excess of blasts [RAEB], 4; chronic myelomonocytic leukemia [CMML], 3; refractory anemia with excess of blasts in transformation [RAEB-T], 4; and refractory cytopenia [RC], 1. Thirteen patients (72%) had chromosomal abnormalities and frequently observed chromosomal abnormalities were trisomy 8, -7/7q-, 20q-, trisomy 1q and 5q-. The mean survival were as follows; RA: 22.5 months, RAEB: 13.2 months, CMML: 15 months, RAEB-T: 5.5 months. Progression to overt leukemia occurred in 5 patients (27.7%): 1 of four patients with RAEB, 1 of three patients with CMML and 3 of four patients with RAEB-T. In conclusion, chromosomal abnormalities were most frequently observed in the patient with RAEB-T who had shortest survival time among the patients with MDS. On the other hand, chromosomal abnormalities were less frequently observed in the patients with RA and they showed relatively better prognosis than the other types of MDS.     

A study of the haematologic spectrum of myelodysplastic syndrome

In 31 patients of myelodysplastic syndrome, RAEB-t was the commonest subtype (29%), and RARS, the lease common (6.4%); 19.4% were characterised as the unclassifiable (UC) group. Pallor was the dominant sign (90.3%). Low haemoglobin in RA & RARS (p<0.05), thrombocytopenia in RAEB-t (p<0.01) and high leuco/monocyte counts in CMML (p<0.001) were observed. Neutropenia occurred most frequently in RAEB & RAEB-t and circulating blasts in all cases of RAEB-t and CMML. Bicytopenia was the commonest finding (58.1%) and pancytopenia the least (16.1%). 84% of marrows were hypercellular and trilineage dysplasia was seen in 68% of patients. Megaloblastoid dyserythropoiesis was the predominant feature in all cases, dysgranulopoiesis in all cases of RAEB, RAEB-t and CMML, and micromegokaryocytes in all cases of RARS, RAEB & CMML were seen. RAEB-t and RAEB (33.3% each) were the predominant groups which progressed to leukemia, FAB AML-M2, being the commonest type (60%).     

Cytogenetic analysis of 54 cases of myelodysplastic syndrome

Fifty-four patients with myelodysplastic syndrome (MDS) (35 men and 19 women aged 34-92 years) were studied cytogenetically. Bone marrow cell culture and chromosome preparation were performed according to four different protocols used in parallel: methotrexate (MTX)-synchronized or thymidine (TdR)-unsynchronized techniques, and presence or absence of 5637 conditioned medium (CM). Some patients responded better to MTX; others had better results with TdR exposure only. Use of 5637 CM generally improved quantity and quality of metaphases. A cytogenetic result was obtained in 53 cases. 60% of the patients had a chromosome abnormality. Percentage of abnormality varied from one French-American-British (FAB) subtype to the other: 62% in refractory anemia with ringed sideroblasts (RARS, 8/13), 50% in refractory anemia (RA, 6/12), 60% in refractory anemia with excess of blasts (RAEB, 3/5), 77% in refractory anemia with excess of blasts in transformation (RAEB-T, 7/9), and 57% in chronic myelomonocytic leukemia (CMMoL, 8/14). Chromosome defects were subdivided into three categories: single, two, and complex defects. The most frequent chromosome abnormalities, either single or one of two or complex defects were del(5q) or monosomy 5 (13 cases), trisomy or rearrangement of chromosome 8 (eight cases), total or partial monosomy or rearrangement of chromosome 7 (eight cases), Y loss (seven cases), and del(20q) (two cases). With the exception of del(5q) in macrocytic RA, this study confirms the absence of chromosome defects specific to each FAB category of MDS. Recurrent defects in MDS are relatively limited, however, in terms of chromosomes involved and type of abnormality. Consequently, these defects, mostly of deleted type, are assumed to play a specific role in the genesis of myelodysplasia.     

Phenotypic and genotypic diversity of human neuroblastoma studied in three IGR cell line models derived from bone marrow metastases

Cytogenetic analysis was performed in 60 patients with primary myelodysplastic syndromes--diagnosed, treated, and followed in our department. In 41 cases, the presence of the NRAS mutation was also evaluated. The aim of this study was to evaluate the prognostic value of chromosomal abnormalities and NRAS mutation. The median age of the patients was 67 years (18-88 years), and the French-American-British classification was as follows: refractory anemia 26, refractory anemia with ring sideroblasts 4, refractory anemia with excess of blast cells 15, refractory anemia with excess of blast cells in transformation 3, and chronic myelomonocytic leukemia 12. Survival analysis was performed for the patients with a normal (n = 35), an abnormal (n = 25) karyotype and with a single (n = 15) or multiple (n = 10) cytogenetic abnormalities. Abnormal karyotypes were detected in 25 of the 60 patients (41.6%). Fifteen of these patients had a single and 10 had two or more lesions. The median survival of the patients with a normal (33.1 months) and with an abnormal (36.5 months) karyotype was not significantly different. Patients with multiple lesions had a reduced median survival compared with patients with single anomalies (19.2 versus 39.7 months, p = 0.5). Patients with an abnormal karyotype progressed to acute leukemia more frequently compared with patients without lesions (36 versus 28.6%, p = 0.5). NRAS mutation was detected in 2 of 10 CMMoL patients studied and in none of the 31 patients with other types of myelodysplastic syndrome. Marrow blasts more than 10% significantly affected survival.     

Refractory anemia with excess of blasts in transformation. Clinical, hematologic, and cytogenetic findings in nine patients

Clinical, hematologic, and cytogenetic data of nine patients with refractory anemia with excess of blasts in transformation (RAEB-t), classified according to the French-American-British Cooperative Group for myelodysplastic syndrome (MDS), are reported. At diagnosis, eight out of nine cases, had chromosomal abnormalities and three out of nine developed acute leukemia. Karyotype studies allowed individualization of two groups of patients: five with nonrandom major karyotype abnormalities (MAKA) including hypodiploidy, chromosomes 5 and 7 involvement, at least four other abnormalities, and a poor prognosis (survival always under 3.5 months); and four patients with either normal karyotypes or minor karyotype abnormalities (MIKA) (no more than three abnormalities) and a better prognosis (survival from 14 to 38 months). Karyotype appears to be a major prognostic factor among RAEB-t.     

Myelodysplastisches Syndrom (MDS)

Myelodysplastic syndromes (MDS) are a heterogenous group of clonal stem cell disorders which generally occur in older adults but may also affect children. Primary MDS should be distinguished from secondary MDS associated with antineoplastic or immunosuppressive therapy (t-MDS), exposure to toxic compounds, or genetic disorders. The establishment of a neoplastic clone is reflected by dysplastic features and impaired function which may affect all three hematopoietic cell lineages. The ineffective hematopoiesis which causes bone marrow failure is accompanied by peripheral blood cytopenia and is considered to result from increased apoptosis, at least in the less advanced MDS stages. The elucidation of the molecular pathogenesis of MDS has provided evidence that chromosomal abnormalities are present in about 50% of patients with primary MDS. They include numerical aberrations such as monosomy 5 or 7, trisomy 8, loss of the Y-chromosome and structural abnormalities such as deletion of the long arm of chromosome 5 (5q-syndrome), 7, or 8. Based on the percentage of blasts (<5%, 5-20%, 20-30%) and the presence of >15% ringed sideroblasts for marrows with <5% blasts, the French-American-British (FAB) classifies MDS into 4 morphologic categories: refractory anemia (RA), refractory anemia with excess of blasts (RAEB), refractory anemia with excess of blasts in transformation (RAEB-t), and refractory anemia with ringed sideroblasts. The fifth morphologic type is chronic myelomonocytic leukemia characterized by peripheral blood monocytosis (>1x10(9)/l). However, a modification of this classification will be proposed by the World Health Organization, with the intention of lowering the threshold for the diagnosis of AML from 30% to 20% blast cells. In patients presenting with cytopenias suggesting impaired hematopoiesis, the initial diagnosis depends mainly on the cytological evaluation of bone marrow and blood smears and the histological findings of trephine bone marrow biopsy. In a retrospective analysis we evaluated the occurrence of the distinct FAB-categories as percentage of the total number of MDS cases diagnosed at the Institute of Pathology of the University of Freiburg. A total of 63% fullfilled the criteria of RA/RARS, 17% of RAEB, 14% of RAEB-t, and 6% of CMML. A fibrotic variant of MDS was observed in 7.67% of all cases, ranging from 2.34% in RA up to 15. 42-15.84% in the categories which did not show significant differences with regard to myelofibrosis. The histologic evaluation of a trephine bone marrow biopsy is of critical importance for the evaluation of fibrotic or hypocellular MDS since these patterns are not reflected by the cytological examination. The combined cytological and histological diagnosis of bone marrow and peripheral blood is a reliable tool for the initial diagnosis of MDS. In addition, cytogenetic and molecular analysis should be performed. Presently, the risk of leukemic transformation is evaluated using the International Prognostic Scoring System for MDS, which is the sum of the scores of bone marrow blasts, karyotypes and cytopenia. In the context of clinical trials therapeutic modalities should be considerd according to the age and the general performance state and the prognostic scores of individual patients.     

Unusual complex hyperdiploid karyotypes in myelodysplastic syndromes

Over an 18-year period, 10 myelodysplastic syndrome (MDS) patients with complex hyperdiploid karyotypes were identified. According to the FAB classification, the 10 patients were subclassified as three refractory anemias (RA), three refractory anemias with excess blasts (RAEB), two RAEB in transformation (RAEB-t), and two unclassified MDS. According to the WHO classification, the diagnoses were two RA, one refractory cytopenia with multilineage dysplasia, two RAEB-1, one RAEB-2, two unclassified MDS, and two acute myeloid leukemia. Six were secondary MDS. Four patients showed marked dyserythropoiesis; three of these were secondary MDS. The chromosome number ranged from 47 to 62, and clonal evolution or composite karyotypes were noted in 7 patients. Seven patients had at least one clone with >50 chromosomes. Recurrent defects included chromosome 5, 17, and 13 abnormalities. Notably, trisomy 8 and monosomy 7 were rare in that group of patients. Three of four patients with marked dyserythropoiesis shared abnormalities of both chromosomes 13 and 17.     

Prognosis of refractory anemias

Several aspects of prognosis of myelodysplastic syndromes were reviewed with special attention to refractory anemia (RA). The median survivals were 14 months in chronic myelomonocytic leukemia, 16 months in RAEB, 42 months in RA, and 58 months in RA with ring sideroblasts (RARS). Cumulative leukemia-free rates at 5 years were 31% in RAEB, 80% in RA, and 92% in RARS. The proportion of cases having very low hazards for leukemic transformation or for nonleukemic death was 92% (RARS), 73% (RA), and 26% (RAEB) for leukemic transformation and 23% (RA) and 29% (RAEB) for nonleukemic death. All RARS cases had hazard for nonleukemic death. In RA, the annual mortality rate was about 5 to 11 times higher than that of age-and sex- matched general population up to 6 years. After which no failure was found in RA cases with survival rate of 33% up to 14 years. The relative importance of hazard from leukemic transformation to nonleukemic death in RA was about one half at presentation, but this declined to less than 10% after 10 years.     

Complex chromosomal abnormalities in a patient with refractory anemia with excess blasts (RAEB)

We report a new case of refractory anemia with excess blasts (RAEB) having complex chromosomal abnormalities. The 5q- associated with RAEB and other preleukemic syndromes was present in 100% of the cells; however, 60% of the cells had a highly unusual derivative chromosome involving the short arm of chromosome 1 and the long arm of chromosome 5, i.e., t(1;5)(p36;q14). Although the patient presented with highly complex chromosomal abnormalities, his initial clinical presentation was that of typical refractory anemia with excess blasts. Shortly after diagnosis (7 months), the patient developed acute leukemia.     

High frequency of human leukocyte antigen class II DRB1*1602 haplotype in Greek patients with myelodysplastic syndrome and of DRB1*1501 in the low-risk subgroup

Myelodysplastic syndromes (MDS) comprise a heterogenous group of clonal hematopoietic disorders in which the immune-mediated pathogenetic mechanisms are under investigation. Overrepresentation of human leukocyte antigen (HLA)-DR2 and its serologic split HLA-DR15 has been associated with low-risk MDS in certain ethnic groups and has been proposed as a predictive factor for a favorable response to immunomodulatory treatment. Because the HLA-DRB1*15 haplotype does not predominate in the Greek population, we investigated the frequency of HLA-DRB1 alleles among 114 patients of Greek origin suffering from various types of MDS: 36 refractory anemia (RA), 24 refractory anemia with ringed sideroblasts (RARS), 19 refractory anemia with excess of blasts (RAEB), 14 refractory anemia with excess of blasts in transformation (RAEB-t), 14 chronic myelomonocytic leukemia, and 7 hypoplastic MDS patients. HLA-DRB1 molecular typing was performed with polymerase chain reaction-sequence specific oligonucleotides and results were compared with that from a previously reported control Greek population. HLA-DRB1*1602 was the only allele that was significantly overrepresented in Greek MDS patients as a whole, whereas HLA-DRB1*1501 allele frequency was significantly higher in Greek patients with low-risk myelodysplasia. Our results suggest the possible value of HLA-DR15 and HLA-DR16 as determinants for immunomodulatory interventions, at least for Greek patients with low-risk MDS.     

A chromosomal profile of polycythemia vera

One hundred four patients with a diagnosis of polycythemia vera and a variable period of follow-up had one or more cytogenetic investigations. Chromosome abnormalities were found in 13% of untreated patients, in 56% of cases treated with radioactive phosphorus (32P) or cytotoxic drugs, and in 85% of patients in which transformation of the disease had occurred. Nonrandom chromosome abnormalities found before treatment included +8, +9, 13q-, 20q-; their prognostic value is little, as they are often associated with longstanding, stable disease. In contrast, 5q- anomaly and the appearance of subclones in patients with an abnormal karyotype were found to be poor prognostic signs, as they are usually coincidental with evolution of the disease to myelofibrosis or leukemia. Chromosomally two patterns of acute leukemia were observed in polycythemia vera patients. The first type resembles de novo acute leukemia, in that the clinical and cytologic characteristics of the disorder are easily defined by FAB criteria and the chromosome changes compatible with the types usually found in those conditions. In the second type, assignment to a FAB morphologic subgroup was more difficult, myelodysplastic changes were often present, and the karyotype showed complex abnormalities frequently involving chromosomes #5 and #7. All these features suggest the occurrence of secondary leukemia.     

29例伴del(20q)骨髓增生异常综合征的细胞遗传学和临床特征

目的 分析伴del(20q)的骨髓增生异常综合征(myelodysplastic syndrome，MDS)患者的细胞遗传学和临床特征。方法 对29例伴del(20q)MDS的细胞遗传学改变、临床表现、实验室检查特点及病程转归进行总结分析。结果 (1)29例del(20q)的MDS中，11例(37．9％)混合正常核型，难治性贫血(refractory anemia，RA)／伴环形铁粒幼细胞增多的难治性贫血(RA with ringed sideroblasts，RAS)组有9例，而原始细胞增多的RA(RA with excess blasts，RAEB)／转变中的RAEB(RAEB in transformation，RAEB-T)组2例；RA／RAS组中缺失以del(20q)(q11)多见(63．2%)，而RAEB／RAEB-T组中以del(20q)(q12)多见(70．0％)；RA／RAS组的附加核型改变和复杂核型改变发生率为26．3％、5．3％，均低于RAEB／RAEB-T组的50．0％和30．0％；(2)伴del(20q)的MDS多表现为两系或3系血细胞减少，几乎全部患者有红系和粒系病态造血，而58．6%的患者有巨核细胞病态造血，13例(44．8％)患者为两系病态造血，14例(48．3％)患者为3系病态造血，另2例为单纯红系病态造血；62．5％患者的有核红细胞糖原染色阳性和中性粒细胞碱性磷酸酶积分减低；81．8％患者有淋巴细胞的免疫学标记表达；(3)2例患者转化为急性非淋巴细胞性白血病(acute nonlymphocytic leukemia，ANLL)M2a型。结论 del(20q)可能是血液肿瘤中一种早期和初步的细胞遗传学异常，伴del(20q)的MDS以两系和3系血细胞减少及病态造血常见，可表达淋巴细胞标记，随病情进展正常核型减少而附加和复杂核型增加。     

Clinical aspects of the myelodysplastic syndromes (MDS) with special reference to refractory anemia with excess of blasts (RAEB)

Clinical features, prognosis and factors influencing survival, as well as long-term evolution of the disease were analyzed in 130 patients with myelodysplastic syndromes (MDS) with particular reference to the refractory anemia with excess of blasts (RAEB). Survival of patients with 3 FAB subtypes, RAEB, RAEB in transformation (RAEB-T) and chronic myelomonocytic leukemia (CMMoL) showing excess blasts was uniformly poor relative to primary acquired refractory anemia (PARA) and primary acquired sideroblastic anemia (PASA). The degree of cytopenias, karyotypic abnormalities, bone marrow cellularity, transition to acute leukemia were not reliable prognostic parameters for discrimination of RAEB with poor or good prognosis. Disease transition was frequently observed in our MDS patient population, at an overall incidence of 37.7%. Transition of PARA to RAEB occurred after a prolonged course in some patients.     

Chromosome analyses in patients with myelodysplastic syndromes: Correlation with bone marrow histopathology and prognostic significance

Summary Chromosome analyses of bone marrow and peripheral blood cells were performed in a total of 51 patients with myelodysplastic syndromes (MDS) simultaneously with histopathological examination of resinembedded bone marrow biopsies. Diagnosis of MDS was established by histopathology according to the French-American-British (FAB) classification, and reassessed by haematological data and clinical course. Clonal karyotypic changes were found in 30 of the 51 patients (59%): in 15 of 19 (79%) patients with refractory anaemia, 7 of 11 (64%) with refractory anaemia and excess of blasts (RAEB), 6 of 10 (60%) with RAEB in transformation, and 2 of 11 (18%) with chronic myelomonocytic leukaemia. The following three features of the histopathology revealed positive correlations with karyotype abnormalities: all cases of myelofibrosis in MDS (7/51) were accompanied by chromosome aberrations, microforms of megakaryocytes with reduced nuclear lobulation were observed in 18 of 30 cases with karyotype changes, and hypocellularity of haematopoiesis was associated with aberrations of chromosome 7 in 2 of 4 cases. No positive correlations were revealed between abnormal karyotypes and the transformation to acute leukaemia. The survival times were significantly decreased in patients with complex (3 and more) karyotype changes, when compared with patients with single (1–2) chromosome aberrations or normal karyotype, independently of the FAB classification.     

An identical t(Y;1)(q12;q21) in two patients with myelodysplastic syndromes

Two male patients with myelodysplastic syndromes, one with refractory anemia with excess blasts (RAEB), the other with chronic myelomonocytic leukemia both had in their bone marrow and peripheral blood cells the same abnormal karyotype 46,X,-Y, + der (Y)t(Y;1)(q12;q21). This abnormality produced trisomy for the 1q21-1qter region of chromosome 1. In addition to the t(Y;1), the patient with RAEB had a del(20)(q11) abnormality in separate CFU-GM and BFUe progenitor cell populations. The t(Y;1) clone of this patient underwent chromosomal evolution with the acquisition of trisomies for chromosomes 2, 6, 8, and 9. Cytogenetic analysis of serial peripheral blood samples showed that the t(Y;1) clone and its derivatives gradually replaced that with the 20q- abnormality. Metaphase cells trisomic for chromosomes 2, 6, 8, and 9 were found predominantly in the CFU-GM population and only rarely in BFUe colonies, suggesting that chromosomal evolution was largely confined to the granulocytic lineage.