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An abnormal clone with monosomy 7 and trisomy 21 in the bone marrow of a child with congenital agranulocytosis (Kostmann disease) treated with granulocyte colony-stimulating factor. Evolution towards myelodysplastic syndrome and acute basophilic leukemia.

Cytogenetic analysis of bone marrow cells revealed an abnormal clone with monosomy 7 and trisomy 21 in a 12-year-old child with Kostmann disease (KD). The patient presented with anemia, thrombocytopenia, and splenomegaly after 5 years of treatment with granulocyte colony-stimulating factor (G-CSF). The bone marrow morphology was consistent with the diagnosis of myelodysplastic syndrome (MDS). Administration of G-CSF was discontinued at this point. Bone marrow studies 2 and 5 months later showed persistence of both myelodysplasia and the abnormal clone with monosomy 7 and trisomy 21. Monosomy 7 was also confirmed by fluorescence in situ hybridization (FISH). After 2 months of follow-up, the patient presented with acute basophilic leukemia, a very rare variant of acute myeloid leukemia (AML), expressing the same bone marrow chromosome abnormalities as observed earlier. This is a rare case of KD with prolonged survival and a cytogenetically abnormal clone evolving to MDS and acute basophilic leukemia. The significance of monosomy 7 and trisomy 21 in KD treated with G-CSF is discussed.

Agranulocytosis↗

Myelodysplastic syndrome associated with monosomy 7 in childhood: a retrospective study.

Myelodysplastic syndrome (MDS) is a clonal hematopoietic stem cell disorder characterized by ineffective hematopoiesis, peripheral cytopenia, and dysplastic changes in the bone marrow. Monosomy 7 or partial loss of 7q is a common cytogenetic abnormality in MDS patients and is associated with poor prognosis. This study examined eight patients with monosomy 7 and MDS. Five MDS patients with monosomy 7 progressed to acute leukemia: three cases transformed into acute myelogenous leukemia (AML) in a mean time of only 4.6 months and two cases into acute lymphoblastic leukemia (ALL) in a mean time of 9 months. To our knowledge, this is the first report showing progression of monosomy 7 associated with MDS to ALL in the childhood period.

Acute Disease↗

Prognostic implications of monosomy 3 in uveal melanoma.

BACKGROUND: A high proportion of patients with uveal melanoma die of metastatic disease. In a subgroup of uveal melanomas there is the loss of one chromosome 3. To assess the prognostic implications of this genetic anomaly, we studied 54 patients for a median of 3.4 years. METHODS: 180 patients underwent primary enucleation for malignant uveal melanoma at the Ophthalmology Department of the Universitätsklinikum Essen between 1987 and 1993. Tumour material was available for chromosome analysis and DNA preparation from 69 of these patients (for logistic reasons unlikely, we believe, to introduce bias). 15 patients were excluded from our study: nine because the methods for assessment of monosomy 3 were unsuccessful; five because of insufficient information about their relapse status; one because histopathological data were incomplete. Of the 54 remaining patients, the tumours of 16 were assessed for copy number of chromosome 3 by karyotype analysis, of 30 by comparative genomic hybridisation, and of eight by both techniques. Clinical status was assessed by contact with family doctor or a clinical check up. Statistical analysis was by the log-rank test and Cox proportional-hazard regression. FINDINGS: The tumours of 30 patients had monosomy 3. 17 (57%) of these patients relapsed with metastatic disease, and the 3-year relapse-free survival rate was 50%. By contrast, of the 24 patients whose tumours had retained both chromosomes 3, none developed metastatic disease. In univariate analysis monosomy 3 was the most significant (p < 0.0001) predictor of poor prognosis in uveal melanoma, followed by tumour location (p < 0.0007) and tumour diameter (p < 0.0021). Histopathological subtype, age, sex, extrascleral growth, and tumour thickness had no additional predictive value. INTERPRETATION: In uveal melanoma, monosomy 3 is a significant predictor of both relapse-free and overall survival.

Aged↗

Chromosome 7 monosomy and deletions in myeloproliferative diseases.

We studied deletion and monosomy of chromosome 7 in 150 patients with myeloproliferative diseases. We found 8/150 patients with monosomy 7 by cytogenetics and 4/150 with deletions of the long arm of chromosome 7 by restriction fragment length polymorphism (RFLP) analysis performed with Southern and polymerase chain reaction. To overcome limitation of RFLP analysis, we restricted loss of heterozygosity study with microsatellites to 45 patients, observing deletion 7q31.1 in 7/45 patients. In all patients with molecular alterations the deletion was observed only in myeloid cells, while the monosomy was detected in both myeloid precursor and lymphocytes. This finding suggests a CD34-totipotent stem cell origin for the monosomy and a colony forming unit - granulocyte, erythrocyte, monocyte, megakaryocytes (CFU-GEMM) stem cell origin for the deletions.

Chromosomes, Human, Pair 7↗

Familial myelodysplastic syndromes, monosomy 7/trisomy 8, and mutator effects.

A family is reported, in which two sisters presented with myelodysplastic syndrome (MDS), namely refractory anemia with excess of blasts in transformation (RAEB-t), and refractory anemia (RA). Bone marrow chromosome changes were present in both: trisomy and tetrasomy 8 (with a pericentric inversion of one chromosome 8) in the older sister, and monosomy 7 (with clones with additional trisomies 19 and 21) in the younger one. Molecular data were obtained on the parental chromosome involved in these numerical anomalies, which proved to be of paternal origin in these cases. The observations of this family, and a review of familial cases of MDS/acute myeloid leukemia (AML), led us to consider that they may be divided into two groups: those which arise on the basis of a Mendelian predisposing disorder exerting a mutator effect, often with the acquisition of monosomy 7, and those in which no specific Mendelian predisposing disease is recognized, as the familial monosomy 7 cases and the one reported here. We postulate that in these families an inherited mutator effect is present and that it causes a karyotype instability, which leads to MDS/AML, often through the acquisition of monosomy 7 and trisomy 8.

Adolescent↗

Monosomy 16 as the sole abnormality in myeloid malignancies.

The majority of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients reported with chromosome 16 abnormalities had the inv(16)(p13q22) or t(16;16)(p13;q22) rearrangements, which were associated with a favorable prognosis. In contrast, del(16)(q22) was reported less commonly but was associated with a less favorable prognosis. We describe an 80-year-old woman who presented with MDS (refractory anemia). Chromosome analysis from bone marrow aspirate cultures showed monosomy 16 as the sole cytogenetic abnormality. Comparison of this patient with previously reported cases of monosomy 16 showed that this uncommon abnormality was associated with myeloid disorders. Monosomy 16 patients, similar to del(16)(q22) patients, tended to be elderly, presented with MDS or AML, and had a poor prognosis. The similarity in clinical course for del(16)(q22) and monosomy 16 patients suggests that the phenotype in both groups resulted from loss of important gene(s) on 16q, as distinct from the fusion gene product identified in the inv(16) and t(16;16) rearrangements.

Aged↗

Evidence implicating heterozygous deletion of chromosome 7 in the pathogenesis of familial leukemia associated with monosomy 7.

Complete or partial monosomy 7 is a recurring cytogenetic abnormality in acute myelogenous leukemia (AML) and myeloproliferative syndromes (MPS) and is particularly common in patients with Fanconi's anemia and in secondary AML. A familial form of monosomy 7 has been recognized in which two or more siblings develop MPS or AML before age 20. We tested the hypothesis that a recessive cancer susceptibility locus on chromosome 7 was important in the pathogenesis of leukemia in familial monosomy 7 by determining the parental origins of the chromosome 7 retained in the bone marrows of three pairs of affected siblings. We found no overlapping region where all three pairs retained DNA derived from the same paternal or maternal chromosome. These data suggest that inactivation of a single allele of a putative tumor-suppressor gene may be sufficient to contribute to leukemic transformation in familial monosomy 7.

Adolescent↗

Prenatal diagnosis and characterization of an unbalanced whole arm translocation resulting in monosomy for 18p.

Monosomy for the short arm of chromosome 18 is one of the most frequent autosomal deletions observed. While most cases result from terminal deletion of 18p, 16% of cases reported were as a result of an unbalanced whole arm translocation resulting in monosomy 18p. The origin and structure of these derivative chromosomes were reported in only a few cases. We report the prenatal diagnosis and characterization of a new case of monosomy 18p as a result of an unbalanced whole arm translocation. Amniocentesis was performed at 15 weeks of gestation on a 34-year-old woman initially referred for advanced maternal age. Holoprosencephaly was identified by ultrasound at the time of amniocentesis. Karyotype analysis showed an unbalanced whole arm translocation between the long arm of one chromosome 18 and the long arm of one chromosome 22, 45,XX,der(18;22)(q10;q10), in all metaphases. In effect, the fetus had monosomy for 18p. Parental karyotypes were normal, suggesting a de novo origin for the der(18;22). Fluorescence in situ hybridization (FISH) analysis was performed with alpha-satellite probes D18Z1 and D14Z1/D22Z1 to identify the origin of the centromere on the der(18;22). Signal was observed with both probes, indicating that the centromere was composed of alpha-satellite DNA from both constituent chromosomes. Genotyping of the fetus and her parents with chromosome 18p STS marker D18S391 showed only the paternal 187 bp allele was present in the fetus, indicating that it was the maternal chromosome 18 involved in the der(18;22). This case and previous reports show that de novo unbalanced whole arm translocations are more likely to retain alpha-satellite sequences from the two chromosomes involved.

Adult↗

Deletion of 7p or monosomy 7 in pediatric acute lymphoblastic leukemia is an adverse prognostic factor: a report from the Children's Cancer Group.

Monosomy 7 or deletions of 7q are associated with many myeloid disorders; however, the significance of such abnormalities in childhood acute lymphoblastic leukemia (ALL) is unknown. Among 1880 children with ALL, 75 (4%) had losses involving chromosome 7, 16 (21%) with monosomy 7, 41 (55%) with losses of 7p (del(7p)), 16 (21%) with losses of 7q (del(7q)), and two (3%) with losses involving both arms. Patients with losses involving chromosome 7 were more likely to be > or =10 years old, National Cancer Institute (NCI) poor risk, and hypodiploid than patients lacking this abnormality. Patients with or without these abnormalities had similar early response to induction therapy. Event-free survival (EFS) and survival for patients with monosomy 7 (P<0.0001 and P=0.0007, respectively) or del(7p) (P<0.0001 and P=0.0001, respectively), but not of patients with del(7q), were significantly worse than those of patients lacking these abnormalities. The poorer EFS was maintained after adjustment for a Philadelphia (Ph) chromosome, NCI risk status, ploidy, or an abnormal 9p. However, the impact on survival was not maintained for monosomy 7 after adjustment for a Ph. These results indicate that the critical region of loss of chromosome 7 in pediatric ALL may be on the p-arm.

Child↗

Genomic gains and losses influence expression levels of genes located within the affected regions: a study on acute myeloid leukemias with trisomy 8, 11, or 13, monosomy 7, or deletion 5q.

We performed microarray analyses in AML with trisomies 8 (n=12), 11 (n=7), 13 (n=7), monosomy 7 (n=9), and deletion 5q (n=7) as sole changes to investigate whether genomic gains and losses translate into altered expression levels of genes located in the affected chromosomal regions. Controls were 104 AML with normal karyotype. In subgroups with trisomy, the median expression of genes located on gained chromosomes was higher, while in AML with monosomy 7 and deletion 5q the median expression of genes located in deleted regions was lower. The 50 most differentially expressed genes, as compared to all other subtypes, were equally distributed over the genome in AML subgroups with trisomies. In contrast, 30 and 86% of the most differentially expressed genes characteristic for AML with 5q deletion and monosomy 7 are located on chromosomes 5 or 7. In conclusion, gain of whole chromosomes leads to overexpression of genes located on the respective chromosomes. Losses of larger regions of the genome translate into lower expression of the majority of genes represented by only one allele. The reduced expression of these genes is the most characteristic difference in gene expression profiles between AML with monosomy 7 and AML with deletion 5q, respectively, and other AML subtypes. Therefore, these data provide evidence that gene dosage effects gene expression in AML with unbalanced karyotype abnormalities. Losses of specific regions of the genome determine the gene expression profile more strongly than the gain of whole chromosomes.

Chromosome Aberrations↗

Four novel non-random chromosome rearrangements in B-cell chronic lymphocytic leukaemia: 6p24-25 and 12p12-13 translocations, 4q21 anomalies and monosomy 21.

Nine patients with previously unreported chromosome changes were identified among 209 B-cell chronic lymphocytic leukaemia (CLL) cases: three patients had a translocation involving 6p24-25; three had a 12p12-13 translocation; two had 4q21 involvement (one with coexisting 6p anomaly); and two had monosomy 21. Interphase fluorescence in situ hybridization (FISH) detected some cryptic aberrations (+12, 6q-, 17p-, 11q-) in those patients with 6p translocations, whereas only a cytogenetically undetected 13q14 deletion was found in the remaining cases. Atypical morphology was noted in six cases, including both cases with monosomy 21, two cases with 6p and 4q21 anomaly and one case with 12p involvement. Four of these cases also had more than one phenotype deviation with respect to the classical CLL phenotype. Disease progression after 21-51 months (median 41) was noted in two cases with 6p and 4q21 involvement and in one case with 12p anomaly and monosomy 21. We arrived at the following conclusions: (i) 6p24-25 and, possibly, 4q21 lesions represent non-random events in CLL, occurring in association with other well-known unbalanced rearrangements; (ii) 12p rearrangements and monosomy 21 may possibly represent early chromosome defects that are not associated with the classical DNA gains and losses known to be present in the majority of CLL; and (iii) atypical morphology and immunophenotype as well as disease progression were frequently observed in these cases

Aged↗

Possible evidence for genomic imprinting in childhood acute myeloblastic leukaemia associated with monosomy for chromosome 7.

Monosomy or deletion of chromosome 7 is a frequent finding in both de novo and secondary acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS). Based on analysis of deletions of chromosome 7 in such patients, it has been suggested that there is a critical region of the chromosome lying within bands q21-q31. We have examined bone marrow and peripheral blood samples from 10 patients with MDS, AML and biphenotypic acute leukaemia who had monosomy for or rearrangement of chromosome 7, seeking evidence of non-random allele loss that might suggest the presence of imprinted genes on the chromosome. Bone marrow cells from one patient with the infant monosomy 7 syndrome had loss of maternal alleles as did two patients with biphenotypic leukaemia. Five out of five patients with MDS and both patients with de novo AML had loss of paternal alleles. One of the latter patients had a del(7) (q31q36) rather than monosomy 7. These findings suggest that imprinting of a gene(s) on chromosome 7, within the bands q31-q36, may be of importance in MDS and AML. Despite the reported increased incidence of AML amongst relatives of patients with cystic fibrosis (CF) the gene for which lies in chromosome region 7q31, none of the patients nor parents studied here appeared to be carriers of the most common gene mutation seen in patients with CF, the delta F508.

Acute Disease↗

Putative monosomy 21 in two patients: clinical findings and investigation using fluorescence in situ hybridization.

Complete monosomy 21 is claimed to be a rare chromosomal disorder in which the cytogenetic investigation is bedevilled by technical difficulties. We describe the disparate clinical features in two patients in whom an initial diagnosis of monosomy 21 was made by routine karyotyping. Fluorescence in situ hybridisation (FISH) confirmed a translocation of chromosome 21 material to the short arm of chromosome 5 and to the X chromosome, respectively. The usefulness of FISH in the investigation of subtle chromosomal rearrangements is hereby demonstrated. These findings also cast doubt on the existence of "pure" monosomy 21 as an entity, and suggest that partial monosomy 21 is a more likely occurrence.

Abnormalities, Multiple↗

Monosomy 7 predisposes to diabetes insipidus in leukaemia and myelodysplastic syndrome.

We studied the chromosomes in the bone marrow of 4 patients who had both diabetes insipidus (DI) and acute non-lymphocytic leukaemia. Clinical findings suggested that, in each case, myelodysplastic syndrome had preceded the onset of acute leukaemia. Two other such patients described in the literature had had a banded karyotype study of bone marrow cells. All 6 patients had deletions of chromosome 7. 3 had monosomy 7 as the sole cytogenetic abnormality, 2 had monosomy 7 associated with other clonal abnormalities and 1 had del(7)(q22) in association with other abnormalities. These data suggest that monosomy 7 or perhaps monosomy for 7q22-qter predisposes to DI. The mechanism by which the proposed predisposition is produced remains to be clarified.

Acute Disease↗

In vivo detection of monosomy 3 in eyes with medium-sized uveal melanoma using transscleral fine needle aspiration biopsy.

PURPOSE: Cytogenetic prognostication of choroidal melanoma, particularly monosomy 3 detections, is limited to enucleated eyes or resected tumors. The authors developed an in vivo technique to detect monosomy 3 using transscleral fine needle aspiration biopsy (FNAB). METHODS: Eight eyes with medium-sized choroidal melanoma were included in this prospective study. A 25-gauge transscleral FNAB was performed during surgical procedure for brachytherapy, just before applying the radioactive plaque over the tumor base. Sampled material underwent fluorescence in situ hybridization (FISH) with centromeric probes for chromosome 3. Follow-up was >12 months. RESULTS: Transscleral FNAB yielded sufficient material in 7 of 8 eyes (87.5 %). Five of seven eyes had monosomy 3. No early or late complications were detected. CONCLUSIONS: This study demonstrates that medium choroidal melanomas may be safely sampled by intraoperative transscleral FNAB to detect monosomy 3 in vivo.

Aged↗

[Monosomy 1p and alkaline phosphatase in meningiomas. Citopathological, histochemical and genetical study in 10 tumors].

BACKGROUND: Cytogenetic studies in meningiomas show that 1p monosomy constitutes an important factor involved in their progression. Genes coding for unspecific alkaline phosphatase (AP-un) are located in this chromosome, in particular in 1p34-p36.1. This enzyme is widely distributed in the body and it is also found in meningiomas. The loss of expression of this enzyme in meningiomas has been associated with the presence of 1p monosomy in these tumors. PATIENTS AND METHOD: We studied 10 meningiomas from 8 patients which shared 1p monosomy. Three tumors had a benign morphologic pattern; it was atypical in two and malignant in five cases. We performed a cytogenetic study and FISH as well as a determination of AP-un in tumor cells. RESULTS: In 8 of ten cases, a loss of AP-un expression was observed. One case displayed positivity in 20% cells. In a positive case, activity was demonstrated in 80% cells. CONCLUSIONS: Our work aimed at analysing the relationship between loss of expression of AP-un, 1p monosomy and the aggressiveness of meningioma. Our results back the interest in determining this enzyme in tumor cells as a quick method with important prognostic value.

Adult↗

Mutations of the ras proto-oncogenes in childhood monosomy 7.

ras gene mutations are the most frequent molecular changes found in the preleukemic syndromes of adults and may play a role in initiating these diseases and in their progression to acute leukemia. However, little is known about the incidence or importance of these genetic mutations in childhood myeloproliferative states (MPS). The bone marrow (BM) monosomy 7 syndrome accounts for a large percentage of childhood MPS. Although the duration of the MPS is quite variable, children with monosomy 7 eventually develop acute myeloid leukemia (AML). We investigated 20 children (13 with MPS, 7 with AML) with BM monosomy 7 or 7q- for the presence of ras gene mutations using the polymerase chain reaction and hybridization with mutation-specific oligonucleotides. Mutations of N-ras and K-ras were detected in three children. Two patients carrying a ras mutation were in the myeloproliferative phase, and one had acute leukemia. All three patients with ras mutations either died of their disease or relapsed after BM transplantation as compared with 8 of 17 without ras mutations. However, this difference is not statistically significant (P = .14, not significant). We conclude that ras mutations are observed in childhood monosomy 7, though less frequently than in adult MDS, and may play a limited role in the progression of this disease to acute leukemia. More patients are needed to address the prognostic role of ras mutations in this rare disease.

Bone Marrow↗

Interphase cytogenetics by fluorescent in situ hybridization (FISH) for characterization of monosomy-7-associated myeloid disorders.

By circumventing the need for metaphase preparations, fluorescent in situ hybridization (FISH) on interphase nuclei using chromosome-specific probes is a promising tool for the study of numerical chromosome aberrations not only in proliferating, but also in non-dividing cells. We analyzed 15 cases of monosomy-7-associated myeloid disorders with a biotinylated probe to the (peri)centromeric region of chromosome 7. Monosomy 7 was readily confirmed in all cases during active disease. In two patients only a minority of nuclei was monosomic, whereas cytogenetics had shown all metaphases to be missing one chromosome 7. FISH in one of them was able to identify a small marker chromosome as isolated pericentromeric region of chromosome 7. Minimal residual disease however could not be detected in three remission samples analyzed, as percentages of disomic nuclei were within the range of normal controls (96.8% 2.1%). In order to determine lineage involvement of the monosomic clone, a recent technique combining immunophenotyping and FISH (FICTION) was performed in one patient with AML after MPD. Monosomy 7 was found in virtually all myelomonocytic and erythroid cells (as discriminated by lineage-specific antibodies), in a part of CD34-positive precursor cells, but not in lymphocytes. We conclude that monosomy 7 in this patient is restricted to an early committed progenitor cell capable of erythroid and myelomonocytic differentiation.

Adolescent↗