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PubMed1997

Monosomy 6 in human cultured fibroblast-like cells after long-term stimulation with acidic fibroblast growth factor (FGF1).

Long-term exposure to fibroblast growth factor type 1 (FGF1) of fibroblast-like cells derived from neurofibromas of patients with neurofibromatosis type 1, from angiofibromas of patients with tuberous sclerosis, and from foreskin of unaffected donors resulted in the outgrowth of monosomy 6 in 7 out of 14 cell lines examined. After their initial detection by cytogenetic analysis, the proportion of cells which had lost one chromosome 6 was monitored by FISH using a-satellite probes specific for chromosome 6 and 7, and by PCR analysis of polymorphic microsatellite markers. Monosomy 6 exceeding baseline levels developed only in cultures exposed to FGF 1, and the emergence of monosomic cells could not be correlated with a given donor's genotype. During serial culture, the proportion of monosomic cells increased to over 90% in 5 of the 7 affected strains. A conspicuous change of cellular morphology from spindle-shaped to more epithelial-type cells was noted in monosomic cultures, even though none of them converted to a permanent cell line during the observation period. We conclude that long-term exposure of human fibroblast-like cell strains to FGF1 results in the emergence of monosomy 6 in 50% of the cultures so treated. A selective advantage for such monosomic cells is the most likely explanation for their steady increase during serial culture.

Adult↗
PubMed1989

Familial bone marrow monosomy 7. Evidence that the predisposing locus is not on the long arm of chromosome 7.

Loss of expression of a tumor-suppressing gene is an attractive model to explain the cytogenetic and epidemiologic features of cases of myelodysplasia and acute myelogenous leukemia (AML) associated with bone marrow monosomy 7 or partial deletion of the long arm (7q-). We used probes from within the breakpoint region on 7q-chromosomes (7q22-34) that detect restriction fragment length polymorphisms (RFLPs) to investigate three families in which two siblings developed myelodysplasia with monosomy 7. In the first family, probes from the proximal part of this region identified DNA derived from the same maternal chromosome in both leukemias. The RFLPs in these siblings diverged at the more distal J3.11 marker due to a mitotic recombination in one patient, a result that suggested a critical region on 7q proximal to probe J3.11. Detailed RFLP mapping of the implicated region was then performed in two additional unrelated pairs of affected siblings. In these families, DNA derived from different parental chromosome 7s was retained in the leukemic bone marrows of the siblings. We conclude that the familial predisposition to myelodysplasia is not located within a consistently deleted segment on the long arm of chromosome 7. These data provide evidence implicating multiple genetic events in the pathogenesis of myelodysplasia seen in association with bone marrow monosomy 7 or 7q-.

Adolescent↗
PubMed2003

Refractory anemia in childhood: a retrospective analysis of 67 patients with particular reference to monosomy 7.

Primary myelodysplasia (MDS) without an increased number of blasts is a rare finding in childhood. We performed a retrospective analysis of 67 children with a diagnosis of primary MDS to determine the clinical and hematologic course of the disease. The median age at diagnosis was 8.3 years (range, 0.3-18.1 years). In contrast to refractory anemia in adults, 44% of patients had hemoglobin levels greater than 10 g/100 mL. The median white blood cell count and the absolute neutrophil count were 3.6 x 109/L and 0.9 x 109/L, respectively. Seventy-five percent of patients had thrombocytopenia. Bone marrow was hypocellular in 43% of the patients. Results of cytogenetic analysis showed monosomy 7 in 49%, trisomy 8 in 9%, and other abnormalities in 9% of the patients. The probability of survival 10 years after diagnosis was 0.48 (standard error [SE] = 0.10). Patients with monosomy 7 had significantly higher estimated probabilities of progression to advanced MDS than did patients with other chromosomal anomalies or normal karyotype. Of the 67 children, 41 underwent allogeneic stem cell transplantation (SCT). Patients whose disease did not progress to advanced MDS before SCT had significantly greater probability of survival than patients who experienced progression (0.76 [SE = 0.09] vs 0.36 [SE = 0.16]). SCT improved the outcomes for patients with monosomy 7 and should be offered early in the course of the disease. Recommendations for best treatment options for children with other chromosomal abnormalities or normal karyotype may have to await results of prospective clinical trials.

Adolescent↗
PubMed2000

[Transformation of severe aplastic anemia to myelodysplastic syndrome with monosomy 7 in a patient who achieved transfusion independence after immunosuppressive therapy].

A 72-year-old woman was given a diagnosis of severe aplastic anemia, and treated with anabolic steroid and cyclosporin A starting in October 1996. Because this treatment was ineffective, anti-thymocyte globulin (ATG) therapy was started in September 1997. In May 1998, chromosome analysis revealed transformation to myelodysplastic syndrome (MDS), refractory anemia with excess of blasts with monosomy 7 in 60% of metaphase cells. The patient showed gradual hematologic improvement and became transfusion independent. Despite progression to acute myeloid leukemia (FAB-M6) with monosomy 7 in 100% of metaphase cells in December 1998, the hemoglobin level recovered to 13.2 g/dl. In May 1999 the blasts increased rapidly and transformation to acute myelomonocytic leukemia (FAB-M4) was diagnosed. The patient was treated with low-dose Ara-C and aclarubicin with no improvement and died in August 1999. This case demonstrated the transformation of severe aplastic anemia to acute myeloid leukemia via MDS with monosomy 7 associated with transfusion independence after immunosuppressive therapy. These findings suggested a close relationship between aplastic anemia and hypoplastic MDS and the possibility of hematologic improvement based on the growth advantage of abnormal clones.

Aged↗
PubMed2002

Secondary acute myeloid leukaemia with monosomy 7 in identical adult twins.

We report the development of secondary acute myeloid leukaemia (AML) with monosomy 7 in identical twins, both at the age of 52 years. In the first twin, induction therapy resulted in complete remission (CR). At relapse 9 months later monosomy 7 was found. The patient died of sepsis 11 months after diagnosis. The other twin presented with leucopenia and thrombocytopenia and refractory anaemia (RA) was diagnosed. During follow-up, fluorescence in situ hybridization analysis demonstrated a monosomy 7 in 11% of the cells. Twenty-eight months following diagnosis the patient progressed to RA with excess blasts in transformation and induction chemotherapy was initiated without achieving CR. Three months later an allogeneic stem cell transplantation from a niece was performed, resulting in CR of the secondary AML.

Acute Disease↗
PubMed1992

No significant effect of monosomy for distal 21q22.3 on the Down syndrome phenotype in "mirror" duplications of chromosome 21.

Three Down syndrome patients for whom karyotypic analysis showed a "mirror" (reverse tandem) duplication of chromosome 21 were studied by phenotypic, cytogenetic, and molecular methods. On high-resolution R-banding analysis performed in two cases, the size of the fusion 21q22.3 band was apparently less than twice the size of the normal 21q22.3, suggesting a partial deletion of distal 21q. The evaluation of eight chromosome 21 single-copy sequences of the 21q22 region--namely, SOD1, D21S15, D21S42, CRYA1, PFKL, CD18, COL6A1, and S100B--by a slot blot method showed in all three cases a partial deletion of 21q22.3 and partial monosomy. The translocation breakpoints were different in each patient, and in two cases the rearranged chromosome was found to be asymmetrical. The molecular definition of the monosomy 21 in each patient was, respectively, COL6A1-S100B, CD18-S100B, and PFKL-S100B. DNA polymorphism analysis indicated in all cases a homozygosity of the duplicated material. The duplicated region was maternal in two patients and paternal in one patient. These data suggest that the reverse tandem chromosomes did not result from a telomeric fusion between chromosomes 21 but from a translocation between sister chromatids. The phenotypes of these patients did not differ significantly from that of individuals with full trisomy 21, except in one case with large ears with an unfolded helix. The fact that monosomy of distal 21q22.3 in these patients resulted in a phenotype very similar to Down syndrome suggests that the duplication of the genes located in this part of chromosome 21 is not necessary for the pathogenesis of the Down syndrome features observed in these patients, including most of the facial and hand features, muscular hypotonia, cardiopathy of the Fallot tetralogy type, and part of the mental retardation.

Adult↗
PubMed2004

Monosomy 7 in patients with aplastic anemia and paroxysmal nocturnal hemoglobinuria with evolution into acute myeloid leukemia.

We report two cases of Thai patients with aplastic anemia/paroxysmal nocturnal hemoglobinuria (AA/PNH) who subsequently developed acute myeloid leukemia (AML) at their terminal phase. Monosomy 7 was demonstrated upon karyotypic analysis of bone marrow in both cases at the time leukemia developed The first patient was a 25-year-old man diagnosed with AA at age 14, recovered from AA at age 15, developed PNH at age 21 and turned into AML at age 25. The second patient was a 27-year-old man diagnosed with PNH at age 22, developed severe AA at age 25 and turned into AML at age 27. This latter patient received anti-lymphocyte globulin when he developed severe AA but did not respond well whereas the first patient fully recovered from AA with anabolic hormone treatment. Time to diagnosis of AML in the patient who received immunosuppressive therapy was strikingly shorter than that who received conventional androgen therapy (2 years vs 11 years after AA, respectively). The presence of monosomy 7 in leukemic cells of both patients emphasizes its central role in the development of AML from AA/PNH. However, other factors such as choice of AA/PNH therapy and patients response may modulate the time to emergence of monosomy 7-carrying AML clone and frank leukemia. Further studies into the biologic and genetic mechanisms involved in the development of leukemic clone arising from AA/PNH should be explored.

Acute Disease↗
PubMed2005

HER2 gene-amplified breast cancers with monosomy of chromosome 17 are poorly responsive to trastuzumab-based treatment.

Although HER2 gene status determines the eligibility of breast cancer patients to trastuzumab therapy, only a fraction of HER2 gene-amplified cancers are actually responsive, indicating that complex genotypical profiles might sustain HER2-targeted therapy responsiveness. To identify genetic factors modulating the response to HER2-targeted therapy, the numerical status of chromosome 17 was evaluated in HER2 gene-amplified tumor specimens from 43 patients who received trastuzumab-based treatment for advanced breast cancer, and in 60 unamplified breast carcinomas. Archival tumor specimens were analyzed by interphase fluorescence in situ hybridization (FISH) using a centromeric probe for chromosome 17 simultaneously with the HER2/neu human gene-specific probe. In the 43 patients who received trastuzumab-based treatment, response rate and time to progression (TTP) were compared between subgroups according to chromosome 17 status. Numerical aberrations of chromosome 17 were found in 65% of HER2-amplified tumors (single centromeric signal, 44%; >3 centromeric signals, 21%) and 60% of unamplified cancers (single centromeric signal, 43%; >3 centromeric, 17%). In the 43 treated metastatic breast cancer patients, trastuzumab was combined with docetaxel (35 patients), paclitaxel (2 patients), or vinorelbine (6 patients). Response rate was 92% in patients with >2 centromeric signals (chromosome 17 eusomy/polysomy), and 53% in patients whose tumor showed a single signal (chromosome 17 monosomy) (p=0.005). Chromosome 17 numerical status was not found to affect TTP. Multivariate logistic regression analysis confirmed that the effect of chromosome 17 monosomy on tumor response was independent of other potential clinical variables. Our findings suggest that 17 monosomy defines a subgroup of HER2 gene-amplified breast cancer characterized by reduced responsiveness to trastuzumab-based treatment. Further studies on the imbalance between the amplified HER2 gene and functionally antagonist gene(s) on chromosome 17 are warranted.

Adult↗
PubMed1992

Partial monosomy 8p and partial trisomy 8p with moderate mental retardation.

A female patient with mosaicism for partial monosomy 8p and partial trisomy 8p is presented. Her karyotype is 46,XX, del(8)(p21)/46,XX, dup(8)(p21----pter). She showed minimal dysmorphic features, agenesis of the corpus callosum and moderate developmental delay. There is no previous report of mosaicism for partial monosomy and partial trisomy 8p. The clinical findings in the presently described patient are less severe than those reported in cases with only monosomy or trisomy of the distal part of chromosome 8.

Agenesis of Corpus Callosum↗
PubMed1990

Partial trisomy 17q and monosomy 9p due to a familial translocation.

Described is an infant with partial trisomy 17q and monosomy 9p [46,XX,-9,+der(9)t(9;17)(p21;q23)] due to adjacent-1 segregation of a maternal balanced reciprocal translocation. Characteristic clinical features of both partial 17q trisomy and monosomy 9p are present, but the former syndrome is less recognisable in this infant than in previously reported cases due to the concomitant 9p monosomy.

Child, Preschool↗
PubMed1991

P53 gene mutations in acute myeloid leukemia with 17p monosomy.

We looked for mutations of exons 5 to 8 of the P53 gene in 10 patients with acute myeloid leukemia (AML) and 17p monosomy, and 36 patients with AML and no cytogenetic abnormalities of 17p. DNA was analyzed by polymerase chain reaction, single-strand conformation polymorphism analysis, and nucleotide sequencing. Four of the 10 patients with 17p monosomy showed point mutation, single-nucleotide deletion, or insertion in exons 7 or 8. By contrast, only 1 of the 36 patients with AML and no cytogenetic abnormalities of 17p showed a mutation of the P53 gene in exons 5 to 8 (P less than .01). These results suggest that alterations of the P53 gene may have a role in leukemogenesis in some cases of AML. The fact that P53 gene mutations occurred more often in patients with 17p monosomy seems to support the "recessive" model of tumor suppressive activity of the P53 gene rather than the "dominant" model, in which alteration of only one allele is sufficient for the development of malignancy.

Base Sequence↗
PubMed1991

[An autopsy case of acute mixed lineage leukemia with monosomy 7 in a child].

A five-year-old boy initially diagnosed common ALL was developed to acute myelomonocytic leukemia. At onset, the bone marrow was hypercellular and 77% of the cells were blasts, mainly lymphoblast-like cells and cytogenetic study demonstrated 45, XY, -7 in all blasts. Cytochemically most of those blasts were negative for peroxidase, sudan black B, alpha-NB esterase staining. The immunological phenotype was J5 (CD10)+, I2 (HLA-DR)+, SmIg-, CyIgmu-, Leu1 (CD5)-, OKT11 (CD2)-, MY7 (CD13)-, suggesting common ALL. Eight months later, the bone marrow cells were occupied with large sized blasts which were almost positive for peroxidase stain and the cells showed coexpression of Mo1 (CD11b)+, MY4 (CD14)+, MY7+, MY9 (CD33)+, MCS2 (CD13)+, I2+, J5-, B4 (CD19)-, Mo2 (CDw14)-, at relapse. He died 2 years and 6 months after his initial diagnosis. An autopsy was performed which revealed generalized infiltration of leukemic cells and aspergillosis of the lung. In general, monosomy 7 is associated with myelodysplastic syndrome in childhood, and is terminated to acute myeloblastic leukemia. In this case, bone marrow blasts demonstrated monosomy 7 cytogenetically, and this case was considered as an acute mixed lineage leukemia of bilineal type. And this case proved that a monosomy 7 can also be terminated to acute mixed lineage leukemia with both lymphoid and myeloid phenotypes.

Child, Preschool↗
PubMed1987

Partial monosomy 15q due to de novo t(15;22)(q15;p11).

We report a 2-years-old infant who presented psychomotor delay and facial dysmorphic features. He has a partial monosomy of 15q resulting from de novo t(15;22)(q15;p11). Up to now three other cases with a similar 15q monosomy have been reported, but the present case is the first one with a "pure" monosomy 15q.

Child, Preschool↗
PubMed1995

Cytogenetic clonality analysis in myelodysplastic syndrome: monosomy 7 can be demonstrated in the myeloid and in the lymphoid lineage.

Bone marrow and blood from three patients with myelodysplastic syndrome (MDS) and monosomy 7 were studied for cell lineage involvement of the chromosomal abnormality. Cytogenetic involvement of the myeloid and erythroid cell lineages in MDS with monosomy 7 has been shown before. Lymphoid subpopulations have also been investigated but generally with negative results. A combined technique of May-Grünwald-Giemsa (MGG) for cell cytology and interphase fluorescence in situ hybridization (FISH) using a chromosome 7 specific DNA probe was applied. Further, immunophenotype and genotype of the cells were simultaneously examined with alkaline phosphatase anti-alkaline phosphatase (APAAP) immunostaining and FISH. The monosomy 7 was found in the blasts and in all or in subpopulations of myeloid and erythroid cells. T cells (CD3+, CD5+) did not appear to be involved. B cells (CD19+, CD22+) showed a normal distribution of FISH spots in two patients. In one patient however the loss of a chromosome 7 was found in approximately 70% of the cells positive for B cell markers including CD79a. The results of this study show that in some cases MDS is a disease arising in a progenitor cell with repopulative abilities restricted to myelopoiesis and erythropoiesis. In other cases, the pluripotent progenitor cells in MDS may show the capacities to differentiate into B lineage lymphoid cells, as well as suggesting that in those instances MDS represents a condition of more primitive transformed hematopoietic ancestor cells.

Adult↗
PubMed1995

Fluorescence in situ hybridization analysis of minute marker chromosomes in leukemia with monosomy 7.

Monosomy 7 was detected in bone marrow cells from three patients, one with myeloid leukemia, and two others with myelodysplastic syndrome following previous chemotherapy. Fluorescence in situ hybridization (FISH), carried out with an alphoid DNA probe specific for chromosome 7 centromere, showed that a small marker chromosome present in the tumor cells' karyotype of the three patients, was derived from the missing chromosome 7. In two cases, the marker was a ring chromosome, whereas in the third case it was a tiny dot-like chromosome, unnoticed at first examination on R-banded metaphases. In the three cases, the marker was lost in a proportion of tumor cells. FISH experiments suggested that the marker centromere had undergone structural alterations, with a fluorescence pattern distinct from a normal one. On the whole, these data suggest that: firstly, leukemia-associated monosomy 7 results, in a proportion of cases, from a structural event rather than from simple loss of a whole chromosome 7; secondly, interpretation of interphase FISH must be cautious in monosomy 7 evaluation; and thirdly structural alteration of the chromosome 7 derivative alphoid DNA could explain its propensity to segregate unequally and to be lost at mitosis.

Adult↗
PubMedDate not supplied

Detection of unexpected clones of monosomy 7 in childhood acute lymphoblastic leukemia using fluorescence in situ hybridization.

The feasibility of a fluorescence in situ hybridization (FISH) technique for the detection of leukemic clones with masked chromosomal aberration in interphase nuclei was tested in childhood acute lymphoblastic leukemia (ALL). Twenty-one cases of ALL previously studied by classical metaphase cytogenetics were retrospectively analysed using a centromere-specific chromosome 7 probe. Five cases with karyotypic abnormalities of chromosome 7 (2 with trisomy 7, 2 with monosomy 7 and 1 with trisomy & tetrasomy 7) showed a correlation with FISH results, whereas in five other cases monosomy 7 was found in 12-43% of cells only by FISH. The unexpected detection of monosomy 7 in these latter ALL patients suggests that either these clones are quiescent or unable to enter mitosis in vitro. This suggests that FISH and metaphase cytogenetics must be combined whenever possible to obtain comprehensive karyotypic information.

Bone Marrow↗
PubMed1996

Monosomy 7 syndrome associated with congenital adrenal hypoplasia and male pseudohermaphroditism.

BACKGROUND: Bone marrow monosomy 7 is an uncommon disorder of the pluripotent stem cells that leads to frequent childhood infections and leukemia. Primary adrenal hypoplasia occurs very rarely and is incompatible with life. Male pseudohermaphroditism results from inadequate androgen secretion or inappropriate androgen action. We report a case of monosomy 7, adrenal hypoplasia, and male pseudohermaphroditism. CASE: An infant was born with sexual ambiguity and bilateral inguinal masses. Bone marrow karyotype was 45, XY,-7. Serum testosterone level was low normal. The infant died on the fourth day of life. Autopsy revealed severely hypoplastic adrenal glands, inguinal testes, and a vaginal pouch. CONCLUSION: Monosomy 7 and male sexual ambiguity are reported in association with primary adrenal hypoplasia of the cytomegalic (X-linked) type.

Adrenal Glands↗
PubMed1996

[Myelodysplastic syndrome developed in a mother and her son whose bone marrow karyotype showed monosomy 7].

Two familial cases of myelodysplastic syndrome (MDS) are reported, one of whom had an abnormal karyotype of 45, XY, -7 (monosomy 7). Case 1 was a 60-year-old woman developed dizziness and nasal bleeding. She was treated with blood transfusion alone. About 11 months after diagnosis, she died of pneumonia. Case 2 was a 22 year-old man, who was the son of case 1, developed febrile disease because of recurrent skin and oral mucosa infections. He had a partial response to low-dose of cytarabine. Thirteen months after diagnosis, he died of severe pneumonia. Both cases were diagnosed as having refractory anemia with excess of blasts due to peripheral blood and bone marrow findings. Both patients had pancytopenia, erythroid hyperplasia in bone marrow, marked dyserythropoiesis, recurrent infectious diseases and severe pneumonia that resulted in death. These symptoms resembled to those reported for monosomy 7 syndrome. Familial MDS with monosomy 7 is rarely reported. These cases are of interest to investigate hereditary factors of MDS.

Adult↗