A missing group C chromosome in the bone marrow cells of three children with myeloproliferative disease

Childhood myeloproliferative disorders

Disorders classified as paediatric myeloproliferative disorders (MPD), such as juvenile chronic myeloid leukaemia (JCML), and as paediatric myelodysplastic syndrome (MDS), are essentially diseases characterized by abnormal myeloproliferation and they share similar genetic events on chromosome 7. As such, the abnormalities of increased myeloproliferation in childhood (AIMC) should be considered under the same heading. Constitutional and other genetic factors play an essential role in children and include the NF1 gene, whereas toxic exposure is of greater importance in adults. The most common cytogenetic alteration is that of monosomy or deletion of the long arm of chromosome 7. Critical regions have been identified and mapped by fluorescence in situ hybridization (FISH). It appears that the similar critical regions on chromosome 7 are involved, and suggests that these regions may contain genes important in the pathogenesis of AIMC.

Primary myelodysplastic syndrome in children: the clinical experience in 33 cases

We describe the clinicomorphological features in 33 cases of primary myelodysplastic syndrome classified according to the FAB classification which presented to a single centre over a 12 year period. Presenting features were typically related to pancytopenia although hepatosplenomegaly and granulocytic sarcomas were far more prevalent than in the adult population. Morphological assessment of the peripheral blood and the bone marrow showed seven patients had refractory anaemia (RA), 13 patients had RA with excess of blasts (RAEB), nine patients had RAEB in transformation (RAEB-t) and four patients had chronic myelomonocytic leukaemia (CMML). The overall mean survival was short (9.9 months) in all the subgroups and the leukaemic transformation rate was high. None of the patients scored 0-1 according to the Bournemouth Scoring System; four patients scored 2 whereas 29 patients scored 3 to 4. We conclude that unlike adults, the myelodysplastic syndromes in children run an aggressive clinical course, irrespective of the FAB subtype, and the pathogenesis of these diseases in paediatric practice warrants scientific scrutiny. Intensive chemotherapy such as the one used in de novo-AML lead to complete remission in some children and these early results suggest that this should be the treatment of choice in paediatric MDS.

Monosomy 7 syndrome. Clinical heterogeneity in children and adolescents

Bone marrow monosomy 7 is the most frequent karyotypic abnormality found in patients with chronic myeloproliferative disorders. To a review of 46 previously reported pediatric patients we add three additional cases. Clinical presentation is usually dependent upon which cell lines are most perturbed in this pluripotent stem cell disorder. Sixteen (35%) children presented by their first birthday and 35 (76%) by their sixth birthday. Distinctive differences in presentation exist between infants, children, and adolescents. Younger patients were more symptomatic and had greater degree of hepatosplenomegaly and leukocytosis. The prognosis is very poor and death usually occurs within two years from complications attributable to cytopenias, cellular dysfunction, or transformation to acute nonlymphocytic leukemia. Implications for therapy are discussed.

Biclonal chromosome evolution of chronic myelomonocytic leukemia in a child

A monosomy 7 was first detected in a 6-month-old boy with a chronic myelomonocytic leukemia. After etoposide treatment, relapse occurred after 29 months, with transformation of the disease into an acute myeloblastic leukemia. After bone marrow transplantations, two abnormal clones were found in marrow cells: 45,XY,-7,del(12)(p11p12)(66%), and 45,XY,-7,t(3;12)(q26;p12)(33%). Several karyotypic studies performed until the terminal phase exhibited the persistence of these two clones in the same proportion, although both independently acquired additional and often similar anomalies. The clone with t(3;12) acquired der(7),der(11),der(17),der(8),der(10),-5,-20, and the clone with del(12p), del(5q),der(4),der(8),der(10),der(17),-5,-20. The anomalies in 12p12 appear to represent an important although secondary event of the neoplastic process. The other anomalies may correspond to either those of a secondary acute nonlymphocytic leukemia, since they occurred after treatment by etoposide and alkylating agents, or to the natural evolution of myelomonocytic leukemia.

Juvenile monosomy 7 syndrome: evidence that the disease originates in a pluripotent hemopoietic stem cell

The present study was undertaken to investigate the hemopoietic cell from which malignant change evolves in juvenile dyshemopoiesis with monosomy 7. Two male patients, aged 18 and 5 months, were studied using progenitor assays combined with cytogenetics. Both had hepatosplenomegaly, cytopenias and a cellular marrow. The karyotype in direct marrow was 45,XY-7/47,XY,+8/46,XY in patient 1 and 45,XY,-7/46,XY in patient 2. Patient 1 received chemotherapy but developed acute nonlymphocytic leukemia after 17 months and died 20 months after diagnosis. During this time marrow metaphases with 45,XY,-7 increased to 100% (25/25). Patient 2 received an allogeneic marrow transplant 4 months after diagnosis which did not engraft. In both patients progenitors of both small (CFU-E) and large (BFU-E) erythroid colonies were present at normal frequencies. However, the colonies produced were small and poorly hemoglobinized with some erythropoietin-independent maturation. Progenitors of large granulocyte/macrophage colonies (CFU-GM) were present at an elevated frequency in the marrow of patient 1 and in the blood all progenitor classes were markedly increased. Cytogenetic analysis of colonies from this patient showed BFU-E to be 45,XY,-7 or 47,XY,+8 and CFU-GM to be 45,XY,-7 or 47,XY,+8 or 46,XY. In patient 2, most BFU-E were 45,XY,-7, although a few were 46,XY. These data indicate that malignant change in this disease involves hemopoietic stem cells capable of erythroid and in at least some cases, myeloid differentiation.

Simple monosomy 7 and myelodysplastic syndrome in thirteen patients without previous cytostatic treatment

Thirteen patients with simple monosomy 7 presented with pallor in 11, easy bruisability in five, splenomegaly in four, no infections, refractory anaemia in all, granulocytopenia in seven, monocytosis in three, leucocytosis in four and thrombocytopenia in eight. Peripheral blood and bone marrow findings were consistent with myelodysplastic syndrome (MDS) type I in three, type II in two, type III in two, type IV in three and acute myelofibrosis in three patients. Transformations to acute leukaemia in seven patients were M2 in one, M4 in four, megakaryoblastic in one and undifferentiated in one. Lack of chromosome 7 in 12-85% of analysed cells at initial presentation of MDS progressed to nearly 100% during blastic transformation. At that time an additional change in the long arm of chromosome 3 was seen in two patients and trisomy 8 in 6% of analysed cells in a third case. The median survival time was 12 months for MDS and 3 months for acute leukaemia. Simple monosomy 7 appears to be largely confined to young children and elderly people.

Acute leukemias of childhood: pathologic features

Major advances have been made in the diagnosis and therapy of childhood leukemia over the last two decades (Zuelzer and Flatz, 1960; Miller, 1980; Steinhorn and Myers, 1981; Kobrinsky et al., 1980). Sophisticated phenotypic analysis of these leukemias has partially revealed their complexity; there are at least three to five distinct clinical pathological entities in the childhood leukemia groups. Improved therapy has resulted in marked increases in survival and cures. Less attention has been given to the pathology of childhood leukemia, although the frequency and complexity of tissue examinations have greatly increased. In particular, the pathologic manifestation of relapses, detection of focal leukemia after treatment and the pathology of complications have not been systematically reviewed. Our goal was to look at all of the pathologic manifestations of leukemia and to relate these manifestations to homogeneous patient populations grouped by their type of leukemia. Therefore all of the cytologic, hematologic, histopathologic, ultrastructural and immunologic materials on a consecutive group of leukemic children seen at Vanderbilt from 1970 to 1981 were reviewed; pathologic manifestations of leukemia were then analysed in relationship to diagnostic categories.

Bone marrow necrosis preceding acute lymphoblastic leukemia in childhood

Two patients who presented with bone marrow necrosis and eventually developed acute lymphocytic leukemia are reported, and similar cases in the literature are reviewed. Both patients responded to chemotherapy. Several possible mechanisms are discussed. Bone marrow necrosis appears to be another condition preceding acute lymphocytic leukemia in children.

Cytogenetics of childhood preleukemia

Chromosome studies were done on ten children with childhood preleukemia characterized by anemia, thrombocytopenia, blasts in the circulation, and hypercellular marrow with excess blasts. The syndrome was clinically similar to adult preleukemia (myelodysplastic disorder). A chromosomally abnormal clone was found in the marrow in five patients: three with monosomy 7; one with a chromosome No. 21 replaced by two isochromosomes for 21q; and one with multiple alterations including an extra, abnormal chromosome No. 7. It was not apparent that a karyotypic change indicated a worse prognosis. The observed chromosome abnormalities appeared to overlap less with those in acute nonlymphocytic leukemia occurring de novo than is the case in adults, perhaps reflecting differing contributions of genetic and environmental factors to the pathogenesis of the disease at different ages.

Myeloproliferative syndrome in childhood

This report describes an atypical "myeloproliferative disorder" in a child that evolved over a 6-year period. The clinical and laboratory features resembled the adult type of chronic myelogenous leukemia, but a Philadelphia chromosome was lacking. Although the proper classification of this disorder remains uncertain, the case makes a good point for the use of diagnostic procedures such as the bone marrow core biopsy and cytogenetic studies to help unravel and define the characteristics of these unusual "myeloproliferative" disorders.

Childhood monosomy 7 syndrome

In recent years, chromosomal aberrations in various hematologic disorders have raised a great deal of interest. In fact, several nonrandom chromosomal abnormalities are now recognized to be responsible for a specific type of dyshemopoiesis while others are closely associated with characteristic hematologic features. Monosomy C, later shown to be monosomy 7 by different banding methods, has been described in children in relation to a peculiar myeloproliferative disorder. Retrospective analysis of early cases published in the literature and a recent observation that we wish to report suggest that the most consistent phenotypic expression of monosomy 7 is an increased susceptibility to bacterial infections related to a preleukemic dyshemopoiesis. Acute nonlymphocytic leukemia is the terminal event of this peculiar preleukemic syndrome, and thus suggests that monosomy 7 involves a stem cell already committed to myeloid differentiation.

Ataxia-pancytopenia: syndrome of cerebellar ataxia, hypoplastic anemia, monosomy 7, and acute myelogenous leukemia

In a family with ataxia and pancytopenia, the proband had cerebellar ataxia, developed hypoplastic anemia at age 3 years, and died of acute myelomonocytic leukemia at age 7. Serial cytogenetic studies of the proband's hypoplastic bone marrow over a 25-month period revealed progressive expansion of a clone of cells with C(6 - 12 + X) monosomy from 33% to 94% of metaphases. The missing chromosome by banding was deduced to be No.7. No increased sensitivity of the patient's cells was found in response to ultraviolet or ionizing radiation or to mitomycin C. Cerebellar atrophy was confirmed at autopsy. Family studies revealed cerebellar ataxia in the proband's father and all four siblings. Two brothers, including one with C-monosomy, died with hypoplastic anemia and another brother died with acute myelocytic leukemia. The only surviving sibling is a 19-year-old sister who has unexplained anemia, decreased mitotic activity in bone marrow, and slow progressive cerebellar ataxia. The name ataxia-pancytopenia syndrome is proposed to encourage study of additional patients with this disorder, which predisposes to pancytopenia and acute leukemia.

Monosomy 7 in childhood: a myeloproliferative disorder

Between 1976 and 1979 a myeloproliferative disease associated with cells monosomic for chromosome number 7 in the bone marrow was seen in six boys aged 5 1/2 months to 8 years (median 10 months). Presenting features included hepatosplenomegaly (5/6), respiratory infections (4/6), pallor (2/6) and skin infections (1/6). Haematological features included a leucoerythroblastic anaemia with leucocytosis and thrombocytopenia, and a hyperplastic marrow with a slight excess of blasts. Fetal haemoglobin was normal in four patients and mildly raised in the other two. Neutrophil function tests showed defective chemotaxis with reduced killing, despite a normal NBT test. Cytogenetic analysis of the marrow showed a preponderance of cells with monosomy 7; the blood lymphocytes were cytogenetically normal. In three patients the disease progressed to acute myeloid leukaemia (AML) after 3 weeks to 23 months; the only patient who remitted did so in response to 6-mercaptopurine and prednisolone, but relapsed 16 months later. A fourth child developed massive splenomegaly which initially responded to 6-mercaptopurine and prednisolone, but progressed to myelofibrosis 11 months later. A fifth child died from anaemia and respiratory infection without progression to leukaemia and the sixth patient has not yet developed leukaemia. Monosomy 7 is the diagnostic criterion of one of the more common myeloproliferative states in childhood and carries a high risk of progression to AML. The acute phase is usually resistant to chemotherapy, but even in responsive cases treatment does not result in elimination of the abnormal clone. Allogeneic bone marrow transplantation should be considered in cases with a suitable donor.

Primary myelofibrosis with myeloid metaplasia and cytogenetically abnormal clones in 2 children with Down's syndrome

2 children with Down's syndrome showed severe anaemia, leucocytosis with blastic cells, thrombocytopenia and hepatosplenomegaly. Bone marrow aspirations were near-dry tap and marrow biopsy revealed primary myelofibrosis with myeloid metaplasia (MMM). Their course was short with a blood picture similar to that of leukaemia. They expired 2 months and 21/2 months after diagnosis, respectively. The cases were thought to represent an acute childhood variant of MMM. Cytogenetic study of circulating white cells by 24 h culture without phytophaemagglutinin stimulation revealed aneuploidy in both cases, the first case showing marked aneuploidy with a predominant karyotype of 50,XX,+8,+19,+19,+21 and the second case a mosaic of 47,XX,+G/48,XX+G,+G. The karyotype of phytohaemagglutinin stimulated lymphocytes was 47,XX,+G in both cases. These findings suggest that the abnormal karyotypes are those of circulating blastic cells which are abnormal clones of haematopoietic cells responsible for MMM. In Down's syndrome, MMM might not be so rare as reported.

Preleukemic states in children with acute lymphoblastic leukemia

Two cases are reported of childhood acute lymphoblastic leukemia presenting with preleukemic states and 13 other cases in the literature are reviewed. Hypoplastic anemias, which transiently resolved spontaneously or with steroid therapy, were seen most commonly. Acquired hypoplastic anemias, even when associated with spontaneous resolution, may at times represent a preleukemic state.

Preleukemia in children

Six children who developed acute myelomonocytic leukemia presented with a preleukemic syndrome. The incidence of preleukemic presentation of AMML was 17% of children with acute nonlymphocytic leukemia, or 2.9% of all children with acute leukemia at this institution, incidences similar to those in adults. During the preleukemic phase, which lasted from three to 35 months, all children had anemia, all had infectious complications, and three of six had hemorrhagic tendencies. Three received steroids before the diagnosis of AMML, and all had some objective response. Two patients died before receiving therapy for AMML. Four children who received AMML therapy with combinations including cytosine arabinoside and an anthracycline achieved complete remission. Ultimately, all patients died. Clues to diagnosis of preleukemia include unexplained cytopenias, either absolute or functional, peripheral blasts, progressive megaloblastosis with an elevated B12 value, dyserythropoiesis, abnormalities of nuclear segmentation, nonrandom chromosomal alterations, and reduced marrow colony to cluster ratio in vitro. Until there is a highly effective therapy for ANLL, precisely when to treat the child with preleukemia remains uncertain. However, treatment should be started before infectious complications or hemorrhagic tendencies become life-threatening.

C-group chromosome abnormalities in bone marrow cells of three children with dyshematopoiesis of unknown origin

Clinical and cytogenetic findings in three children with dyshaematopoiesis and bone marrow aneuploidy are described. Monosomy 7 was found in immature cells of one 10-year-old boy with myelofibrosis following a 3 years evolution of severe thrombocytopenia and anaemia. Trisomy 8 was found in 80% of the bone marrow metaphases of a 5 1/2-year-old girl with aplastic anaemia and Australia antigen positivity. During a 3 year observation period the number of cells with trisomy 8 regressed and eventually disappeared. Improvement of her clinical condition is present but still limited. Trisomy 8 was also found in all bone marrow cells of an 8-year-old girl with an undefined myeloproliferative disorder. Her disease was apparently related to collagen-vascular disorders like periarteritis or other necrotizing angiitis and presented with periods of exacerbation and periods of chronic evolution. Periods of exacerbation were accompanied by excessive myeloid proliferation. Repeated bone marrow cytogenetic analysis during the acute and chronic phases showed trisomy 8 in all the metaphases analysed. During the last episode of acute illness, further clonal evolution was observed, characterized by a translocation (8;17).

Trisomy 21 in bone marrow cells of a patient with a prolonged preleukemic phase

The clinical, hematologic, and cytogenetic findings are described in a patient who developed clinical and hematologic features of acute myelogenous leukemia (AML) after a three-year period of observation with unexplained thrombocytopenia. Five months before the diagnosis of AML she developed hepatosplenomegaly and a lupus-like syndrome. At this time she was also found to have trisomy 21 in all bone marrow cells studied, in addition to trisomy 8 in a few cells. The finding of trisomy 21 in all of the bone marrow cells examined could reflect a nonrandom alteration in the leukemic stem line or it might indicate that mosaic patients with trisomy 21 cells in their bone marrow share the increased risk of AML that has been documented for trisomy 21 patients.

The preleukemic syndromes (hematopoietic dysplasia) in childhood

The preleukemic syndrome or hematopoietic dysplasia is a marrow stem-cell disorder with clinically recognizable hematologic abnormalities which precede the development of acute nonlymphocytic leukemia. Its occurrence in childhood is extremely rare; seven "true" cases who fulfill all the criteria for the disorder have been reported until now. The preleukemic syndrome is generally characterized by peripheral cytopenia with fairly specific morphologic abnormalities in cell differentiation. The hematological and clinical features permit recognition of preleukemia even before the development of overt leukemia. Experimental data indicate that preleukemia is an "early" leukemic syndrome in which hematopoietic cell differentiation becomes progressively impaired with termination in the nearly complete maturation block which is characteristic of acute myelogenous leukemia.

A family with acute leukemia, hypoplastic anemia and cerebellar ataxia: association with bone marrow C-monosomy

The eldest brother in a sibship of five children died of acute myelogenous leukemia at 10 years of age. The second and third eldest brothers died of hypoplastic anemia at ages five and nine years, respectively. A surviving 6 year old brother, the proband of the study, has abnormalities that suggest a preleukemic state: mild pancytopenia, platelet dysfunction, immunodeficiency, and bone marrow hypoplasia with approximately 18 per cent blast forms. His 17 year old sister has a mild normochromic normocytic anemia. Cytogenetic studies revealed C-group monosomy in the bone marrows of the proband and the third brother (45, XY, -C); band studies demonstrated that a No. 8 chromosome was missing in the proband (45, XY, -8). At least four of the siblings and their father had cerebellar ataxia, and evidence of a small cerebellum at autopsy examination or by computerized axial tomography. The disorder in this family has major features of two autosomal recessive preleukemic diseases, ataxia-telangiectasia and Fanconi's anemia. However, these and other inherited conditions were excluded by clinical or laboratory criteria, and no environmental causes of the familial disorder were found. The constellation of abnormalities in the family may constitute a new genetic syndrome.

Cytogenetic studies in preleukaemia using the G-banding staining technique

15 patients with preleukaemia were cytogenetically studied during the preleukaemic state by using the G-banding staining technique. It was found that 9 patients had a completely normal karyotype, while the other 6 showed various chromosomal abnormalities, numerical (trisomies in 5 cases) and structural (deletion in 1 case and a marker chromosome in 1 case). The abnormalities concerned group C in all 6 cases, while group A was involved in 3 cases. G-banding technique revealed that trisomy C affected the chromosomes nos 8 (2 cases) and 9 (3 cases); also a deleted chromosome 11 (11q-) was identified in 1 case and a marker chromosome in 1, the origin of which was established as a translocation between chromosomes 3 and 6. The abnormalities of group A concerned chromosome no 3. The abnormalities found in our cases, using the G-banding technique, were similar to those described in acute leukaemia.

Familial acute myelogenous leukemia with associated C-monosomy in two affected members

A family is described in which five members, three sibs in one branch and two sib cousins in another, died of acute myelogenous leukemia. C-Monosomy was found in the marrow of two of the sibs. C-deletion aneuploidy has been increasingly reported in conjunction with abnormal myelopoiesis. It is possible that this chromosomal aberration may serve as a useful clinical marker of the emergence of a leukemic state.

Periodontal disease associated with preleukemic syndrome

A case of preleukemic syndrome associated with severe periodontal disease has been presented for the first time. The clinical, radiographic and hematologic findings have been discussed, as well as medical and periodontal therapy.

Monosomy 7 in two adult patients with acute myeloblastic leukaemia

Two patients with acute myeloblastic leujaemia were found to have a population of bone marrow cells with C-group monosomy. Using the Quinacrine Mustard fluorescence technique the lacking chromosome was in both patients identified as a number 7. Both patients entered a complete remission. Monosomy 7 may indicate a separate entity of acute myeloblastic leukaemia associated with a comparatively favourable prognosis.

Second malignancies complicating Hodgkin's disease in remission

The incidence of second tumours occurring in the course of Hodgkin's disease has been investigated in a series of 452 patients treated with standard chemotherapy or radiotherapy, combination chemotherapy alone, intensive radiotherapy alone, or both intensive radiotherapy and combination chemotherapy administered in sequence. 16 tumours were noted. When analysed according to mode of treatment, 6 cases occurred in a group of 62 patients who received both modalities. When analysed for age, sex, and man-years of follow-up, this group appears to have 14-5 times the risk of developing a second tumour. However, that subgroup which had a complete remission after intensive radiotherapy followed by a relapse of disease, prior to receiving combination chemotherapy, had the highest risk with 18-5 times greater incidence of second tumour than expected. It is noteworthy that, of the 16 second tumours, 2 were acute myeloid leukaemia; in both cases a similar chromosomal abnormality (45 chromosomes, C-group deletion) was noted. The mechanism of oncogenesis may represent a combination of the immunosuppressive effects and cellular effects of those forms of treatment.