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

Clonal cytogenetic abnormalities in bone marrow specimens without clear morphologic evidence of dysplasia: a form fruste of myelodysplasia?

Cytogenetic abnormalities suggestive of a myeloid disorder are occasionally observed in the bone marrow (BM) cells of patients with morphologically and immunohistochemically unremarkable marrow aspirates and biopsies. Between 1994 and 2000, 55 such patients were seen at our institution (34 men; median age of 66 years). The indications for BM sampling included unexplained cytopenias (31 patients), staging or follow-up of a lymphoproliferative disorder or a plasma cell dyscrasia (18 patients), or another miscellaneous reason (6 patients). Specific cytogenetic abnormalities included a 20q deletion or monosomy 20 (10 patients), a chromosome 7 deletion (8 patients), +8 (5 patients), del(5q) or a 5q translocation (4 patients), and del(13q) (2 patients). Eleven patients had a complex karyotype. As of January 2002, 23 of the 55 patients were dead; median follow-up for living patients is 20 months. Of the 23 dead patients, 1 died of acute myelogenous leukemia (AML) and 6 of complications related to cytopenias. This study provides support for obtaining cytogenetic studies in patients with unexplained cytopenias if a morphologic explanation for the cytopenias is lacking. Continued follow-up of this heterogeneous cohort and further studies of similar patients will more clearly define the disease processes and prognosis for this constellation of laboratory findings.

Chronic myelomonocytic leukemia with t(1;3)(p36;q21) and a synchronous gastric cancer

The translocation t(1;3)(p36;q21) has been reported previously in patients with the myelodysplastic syndrome and with acute nonlymphocytic leukemia. It has been reported in only 5 cases of chronic myelomonocytic leukemia and t(1;3)(p36;q21). We observed a case of chronic myelomonocytic leukemia with t(1;3)(p36;q21) complicated by a gastric cancer at the time of diagnosis.

Identification of breakpoint cluster regions at 1p36.3 and 3q21 in hematologic malignancies with t(1;3)(p36;q21)

The reciprocal translocation t(1;3)(p36;q21) is associated with myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML) characterized by trilineage dysplasia, in particular dysmegakaryocytopoiesis, and a poor prognosis. As yet no molecular genetic analyses of the t(1;3) have been reported. In four patients with t(1;3), all of whom had AML-M4, which evolved from MDS, the breakpoints at 3q21 clustered within a 60-kb region centromeric to the breakpoint of the inv(3)(q21q26), whereas the breakpoints at 1p36 clustered within a 90-kb region at 1p36.3. The presence of novel clusters in both the 3q21 and 1p36 breakpoints (BCRs) suggests a common, underlying molecular mechanism for the development of t(1;3)-positive MDS/AML. The Ribophorin I (RPN1) gene close to the BCR at 3q21 was highly expressed without gross structural changes, whereas the GR6 gene located within the BCR at 3q21 was not expressed. No other highly expressed genes were isolated in a 150-kb region at 3q21. Thus, it is likely that a gene at 1p36.3 is activated by the translocation of the 3q21 region or a gene important for transformation lies on 3q21, outside the 150-kb region. Further characterization of the BCRs at 1p36.3 and 3q21 should provide important insights into the molecular genetic mechanisms involved in the genesis of t(1;3)-positive MDS/AML. Genes Chromosomes Cancer 27:229-238, 2000.

Cytogenetic aberrations in myelodysplastic syndrome detected by comparative genomic hybridization and fluorescence in situ hybridization

Conventional cytogenetics (CC) is proven as a diagnostic and prognostic factor in myelodysplastic syndrome (MDS). However, CC may be hampered by insufficient metaphase preparation and cannot analyze interphase nuclei. These problems are solved by using comparative genomic hybridization (CGH). The CGH was applied to samples from 45 patients with MDS, and the results were compared with CC and fluorescence in situ hybridization (FISH). The CC detected aberrations in 12 of 45 samples, including chromosomes 3 (n = 1), 5 (n = 9), 7 (n = 2),8(n = 1), 18(n = 1),21 (n = 1), X (n = 1), and Y(n = 2). In one patient, loss of B and C group chromosomes and a marker chromosome were seen. The CGH revealed chromosomal imbalances in 18 of 45 samples, including chromosomes 5 (n = 11), 7 (n = 2), 8 (n = 1), 18(n = 1), 20(n = 1), 21 (n = 1), X (n = 1), and Y (n = 2). All unbalanced aberrations found by CC were detected by CGH, too. In two patients, the CGH found additional aberrations and redefined the aberrations of the chromosomes of the B and C group in one sample. The FISH confirmed these aberrations. Additionally performed FISH for chromosomes 5, 7, and 8 gave normal findings in all patients found to be normal in CC and CGH. The CGH and FISH confirmed the results obtained by CC. All three techniques showed changes of chromosomes 5 and 7 as the most frequent aberrations, emphasizing the importance of these chromosomes in the development of MDS. Furthermore, the CC is proven as the basic technique for cytogenetic evaluation of MDS.

Laboratory diagnosis of anemia and related diseases using multivariate analysis

To establish a simple computer program for the laboratory diagnosis of anemia and related diseases, multivariate analyses were applied to the results of routine hematological laboratory tests obtained from 48 patients and 51 healthy volunteers. The patients studied were limited to those who had not been treated hematologically by the time of their first visit to our hospital, and their first data obtained in our laboratory were analyzed. Final diagnoses were aplastic anemia (AA) in 21, myelodysplastic syndrome (MDS) in 14, iron deficiency anemia (IDA) in 3, polycytemia vera (PV)in 3, and idiopathic thrombocytopenic purpura (ITP) in 7. Eight parameters, WBC, RBC, Hb, Ht, MCV, MCH, MCHC, and PLT, were transformed to normal distribution and then applied to principal component analysis to evaluate their independence. Very close relationships were observed between Ht and Hb, and between MCV and MCH. One each of these pairs was selected by discriminant analysis and two sets, RBC, MCH, Hb, PLT, and WBC, and RBC, MCV, Ht, PLT, and WBC, were obtained. Two canonical components gave good discrimination of these five diseases and also of normal subjects. When disease prediction was made using this analysis, 37 of 48 patients (77.1%) were predicted correctly, and furthermore, when two disease predictions were allowed, all patients were diagnosed properly. Some overlaps were observed in this two-dimensional coordinate system, especially of AA and MDS, and also with normal subjects. To improve the system further, the additional parameters of age and sex were added to construct a three-dimensional analysis which resulted in much clearer discrimination. The whole procedure described is being developed with subjects who are not taking medication. Subsequently, the general application of this analytical procedure should be limited to only those not on medications. In conclusion, this is in essence a demonstration project; however, this trial of laboratory diagnosis using routine hematological laboratory results appears to be promising. Further extension of the study by increasing numbers of patients and disorders studied, including secondary anemias, will allow the design of diagnostic software for use with personal computers at the sites of primary care.

Trisomy 19 as the sole chromosomal anomaly in hematologic neoplasms

Trisomy 19 was found as the sole chromosomal aberration in three hematologic malignancies: one chronic myelomonocytic leukemia and two cases of of immunophenotypically immature acute myeloid leukemia (AML). A compilation of previously published hematologic neoplasms with +19 as the only change reveals that this anomaly is strongly associated with myeloid malignancies; 25 of 31 cases have been myelodysplastic syndromes (MDS) or AML. Eight of the 11 MDS cases have been either refractory anemia (RA) or RA with excess of blasts, and four of the 14 AML cases have had preleukemic myelodysplastic cases phase, with the +19 accruing during the time of leukemic transformation. The AML cases have, in general, been either or early maturation arrest, i.e. undifferentiated or AML-M1/M2, or of myelomonocytic-monoblastic origin, i.e., AML-M4/M5. None of the MDS or AML cases with +19 had had a previous history of radio- or chemotherapy. We conclude that trisomy 19, as the sole anomaly, is a characteristic abnormality in de novo myeloid malignancies. No clinical features seem to characterize patients with +19 AML and MDS and the prognostic impact of the aberration remains to be elucidated.