Familial myelodysplasia: progressive disease associated with emergency of monosomy 7

Emberger syndrome-primary lymphedema with myelodysplasia: report of seven new cases

Four reports have been published on an association between acute myeloid leukaemia (AML) and primary lymphedema, with or without congenital deafness. We report seven new cases, including one extended family, confirming this entity as a genetic syndrome. The lymphedema typically presents in one or both lower limbs, before the hematological abnormalities, with onset between infancy and puberty and frequently affecting the genitalia. The AML is often preceded by pancytopenia or myelodysplasia with a high incidence of monosomy 7 in the bone marrow (five propositi and two relatives). Associated anomalies included hypotelorism, epicanthic folds, long tapering fingers and/or neck webbing (four patients), recurrent cellulitis in the affected limb (four patients), generalized warts (two patients), and congenital, high frequency sensorineural deafness (one patient). Children with lower limb and genital lymphedema should be screened for hematological abnormalities and immunodeficiency.

The myelodysplastic syndromes

The myelodysplastic syndrome(s) (MDS), bone marrow stem cell malignancies that share pathogenetic overlap with acute myeloid leukemia, are characterized by peripheral blood cytopenias and, in more advanced subtypes, varied degrees of maturation arrest. Premature apoptosis of bone marrow cellular elements contributes to ineffective hematopoiesis, which is exacerbated by stromal production of inflammatory cytokines. Abrogation of the effects of these cytokines represents an area of active clinical research, particularly in the treatment of low-risk MDS. In high-risk MDS, the activation of oncogenes and the inactivation of tumor suppressor genes predominate over inhibitory cytokines as proliferation predominates over apoptosis. Agents such as thalidomide, lenalidomide and the hypomethylating drugs 5-azacytidine and decitabine have shown promising efficacy and tolerability in clinical trials, and may represent a springboard for future treatment combinations.

Immunomodulation in myelodysplastic syndromes

The myelodysplastic syndromes (MDS) - bone-marrow stem-cell malignancies that share pathogenetic overlap with acute myeloid leukemia - are characterized by peripheral-blood cytopenias and, in more advanced subtypes, varied degrees of maturation arrest. Premature apoptosis of bone-marrow cellular elements contributes to ineffective hematopoiesis, which is exacerbated by stromal production of inflammatory cytokines. Abrogation of the effects of these cytokines represents an area of active clinical research, particularly in the treatment of low-risk MDS. Agents such as thalidomide, lenalidomide, and infliximab have shown promising efficacy and tolerability in clinical trials, and may represent a springboard for future treatment combinations.

Inv(1)(p22q25) in chronic myeloproliferative disease: constitutional or clonal defect?

Pericentric inversion of chromosome 1 is uncommon in chronic myeloproliferative disease. We report the occurrence of an isolated inv(1)(p22q25) in two patients with BCR/ABL-negative chronic myeloproliferative disease. The inv(1) is an acquired clonal abnormality in one patient and a constitutional defect in the other. To our knowledge, this is the first report on the occurrence of inv(1)(p22q25) in hematolymphoid malignancies.

Familial myelodysplastic syndrome with early age of onset

A family is described in which three members, the propositus, his brother, and son, developed a myelodysplastic syndrome (MDS) at the ages of 52, 35, and 25, respectively. A fourth member, the paternal uncle of the propositus, was diagnosed with chronic lymphocytic leukemia. Two of the three affected Individuals had megaloblastoid marrows with recognizable bone marrow cytogenetic abnormalities and progressive, nonleukemic bone marrow failure. The propositus was unresponsive to G-CSF and eventually died of sepsis. The second affected family member died of bone marrow transplant complications. The third affected family member underwent bone marrow transplantation and is showing signs of graft survival despite minor complications. The affected members of this pedigree appear to represent a continuum in severity of disease and, therefore, pathogenesis. The pattern of inheritance and clinical progression of the disease suggest a genetic defect which may predispose individuals to the development of MDS.

Myelodysplastic syndromes in children. A critical review of the clinical manifestations and management

The FAB group has defined myelodysplasia in adults but direct application of this categorization to children has been controversial. Consequently, to outline the natural history of the disease better we have retrospectively analysed case reports and series published in English between 1982 and 1996. This study also included children with juvenile chronic myelomonocytic leukaemia (JCML) and monosomy 7 (Mo7). 340 patients were described in 27 publications. The mean presentation age was 5.91 (SD 5.04) years, and 34.9% were female. Constitutional alterations were described in 68 (20%) where refractory anemia (RA) and RA with excess of blasts (RAEB) predominated and were associated with a significantly longer survival. Among all patients progression to higher forms of MDS was noted in 61 (18%). Cytogenetic anomalies were detected in 59% of 227 children, and in 67 it was to Mo7. Amid those with Mo7, the clinical and laboratory characteristics as well as survival, closely followed their FAB type. Of the treatment options described, survival was significantly higher in those who underwent bone marrow transplant (BMT) (46.9%; P = 0.00021). Among children with JMML (CMML/JCML) not receiving a BMT, time to death was shortest in those best described as JCML (absence of constitutional and karyotypic derangement, thrombocytopenia and elevated Hb F). We conclude that children with constitutional abnormalities survive longer, Mo7 disorders are clinically and morphologically heterogeneous and should not be grouped into a single entity and that CMML and JCML may have biological differences. Finally, BMT remains the treatment of choice for those with primary MDS, as intensive chemotherapy is no better than supportive measures.

Familial acute myeloid leukemia with monosomy 7: late onset and involvement of a multipotential progenitor cell

Familial acute myeloid leukemia (AML) with monosomy 7 is a rare syndrome with fewer than 10 families reported. The salient features included a young median age (8 years) at presentation, equal sex preference, and occurrence of cytopenias and myelodysplasia in nonleukemic family members. Owing to its rarity and the fact that many cases were reported quite some time ago, detailed clinicopathologic features of familial monosomy 7 were not available. We describe a family with three siblings affected by AML in whom monosomy 7 was demonstrated. This family showed several unique features, including the late onset of AML (at 34 and 37 years of age in two siblings), and the presence of an antecedent myelodysplastic phase before leukemia development. With fluorescence in situ hybridization, the monosomy 7 clone was shown to be capable of partial maturation, which was consistent with the biologic behavior of myelodysplasia. These observations suggest that familial leukemia with monosomy 7 is probably a multistep leukemogenic process in which monosomy 7 might be but one of the critical steps. Finally, the prognosis in these cases was poor, suggesting that more aggressive therapy may be needed to improve treatment outcome.

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.

Familial Myelodysplastic Syndrome/Acute Myeloid Leukaemia With Monosomy 7: Report of a New Kindred

Familial juvenile myeloid disorders are uncommon, but better understanding of their basis may lead to crucial advances in the study of leukemogenesis. We report a family with three siblings who died of myelodysplasia and/or acute myeloid leukemia at the age of 10, 11 and 16 years, respectively. Two children died of a fulminant generalized varicella. No somatic constitutional abnormalities were found and histories of exposure to common environmental or occupational mutagens were unremarkable. One of the two tested patients had monosomy of the chromosome 7 in all examined metaphases. Therefore, the clinical and genetic findings are consistent with the "Familial Monosomy 7". A constitutional pericentric inversion of chromosome 9 (p11q13) was detected in the karyotype of the father and both analyzed siblings. In addition, clustering of breast cancer was observed in maternal relatives. As the mode of inheritance and the molecular basis of this disease remain obscure, we believe that it is important to report new cases and attempt to study them as thoroughly as possible. We discuss possible mechanisms of familial tendency to myeloid malignancies.

Genetic heterogeneity in familial acute myelogenous leukemia: evidence for a second locus at chromosome 16q21-23.2

The identification of genes responsible for the rare cases of familial leukemia may afford insight into the mechanism underlying the more common sporadic occurrences. Here we test a single family with 11 relevant meioses transmitting autosomal dominant acute myelogenous leukemia (AML) and myelodysplasia for linkage to three potential candidate loci. In a different family with inherited AML, linkage to chromosome 21q22.1-22.2 was recently reported; we exclude linkage to 21q22.1-22.2, demonstrating that familial AML is a heterogeneous disease. After reviewing familial leukemia and observing anticipation in the form of a declining age of onset with each generation, we had proposed 9p21-22 and 16q22 as additional candidate loci. Whereas linkage to 9p21-22 can be excluded, the finding of a maximum two-point LOD score of 2.82 with the microsatellite marker D16S522 at a recombination fraction theta = 0 provides evidence supporting linkage to 16q22. Haplotype analysis reveals a 23.5-cM (17.9-Mb) commonly inherited region among all affected family members extending from D16S451 to D16S289. In order to extract maximum linkage information with missing individuals, incomplete informativeness with individual markers in this interval, and possible deviance from strict autosomal dominant inheritance, we performed nonparametric linkage analysis (NPL) and found a maximum NPL statistic corresponding to a P-value of .00098, close to the maximum conditional probability of linkage expected for a pedigree with this structure. Mutational analysis in this region specifically excludes expansion of the AT-rich minisatellite repeat FRA16B fragile site and the CAG trinucleotide repeat in the E2F-4 transcription factor. The "repeat expansion detection" method, capable of detecting dynamic mutation associated with anticipation, more generally excludes large CAG repeat expansion as a cause of leukemia in this family.

Monosomy 7 and 7q--associated with myeloid malignancy

An association between the complete or partial loss of chromosome 7 and preleukaemic myelodysplasia or acute myeloid leukaemia has been recognized from the early days of tumour cytogenetic analysis. Detection of such abnormalities usually heralds a poor prognosis. The loss of DNA on chromosome 7 has led to speculation that tumour-suppressor genes may play a significant role in this form of leukaemogenesis, although it may be part of a multistep process. A further association with leukaemia secondary to carcinogen exposure including previous chemotherapy or a number of congenital anaemias has increased the interest in discovering the gene or genes on chromosome 7. Banded chromosome analysis has suggested that there are two broad critical regions on the long arm of chromosome 7 at bands 7q22 and 7q34-q36 that may contain the relevant genes. Initial molecular analysis has confirmed these two regions to be of significance. The advent of fluorescence in-situ hybridization techniques has facilitated some definition of the 7q22 region, with identification of candidate genes for further functional analysis. It is becoming clear that there will be more than one gene on chromosome 7 involved in the leukaemic process and with the definition of these genes it may be possible to look for associations with different phenotypes and prognosis. As for the reason for chromosome 7 showing a particular predisposition to total or partial loss we may speculate that the DNA sequence and structure may confer a 'fragility' on the chromosome. A greater understanding of the DNA structure of the long arm may provide real insight into the mechanisms of leukaemia. We would like to speculate in the long term that this could lead to the ability to screen for leukaemia susceptibility and avoidance of 'inducers' in those at risk.

Chromosome 7 and Haematological Malignancies

Abnormalities of chromosome 7 are the most common clonal chromosomal changes observed in myelodysplasia (MDS) and the second most frequent in acute myeloid leukaemia (AML) [1-5]. These changes may consist of long arm deletion (7q-) or total loss of the whole chromosome (monosomy 7) from bone marrow cells [1, 4, 6-24] and was first reported in association with myeloid disease in 1964 with the report of 3 cases of refractory anaemia, granulocytic hyperplasia [25]. The association between chromosome 7 alterations, MDS and AML in children and adults is clear, however, a rare association with lymphoid malignancies has also been recently reported. The abnormalities may occur in de novo MDS/AML, secondary cases following exposure to drugs, radiotherapy and toxins and in addition in a range of constitutional disorders including Fanconi's anaemia, congenital neutropenia and neurofibromatosis type 1 (NF1). The broad spread of conditions in which this consistent genetic change can occur leads one to speculate that there is an underlying instability in chromosome 7 and that genes on this chromosome play a role in the development of malignancy. The loss of DNA associated with malignant progression suggests the presence of a tumour suppressor gene (or genes) [26, 27]. Patients with monosomy 7 usually present as classical MDS with abnormal erythroid, megakaryocyte and myeloid differentiation [7, 28]. From a mechanistic perspective, increased cell proliferation and apoptosis is a common feature possibly induced by the failure of normal haematopoietic maturation. In all groups the presence of chromosome 7 abnormalities defines a poor prognostic group [29]. The majority of patients with MDS transform to a form of acute leukaemia resistant to therapy, including bone marrow transplantation (BMT). Although fluorescence in situ hybridization (FISH) has accelerated the study of these disorders at the cytogenetic and molecular levels, [4, 30, 31, 32, 33] no gene has been clearly implicated. A few candidate genes are under investigation. While the loss of chromsome 7 material is crutial in the malignant process it is almost certainly not the primary molecular abnormality. An initiating event genetic event predisposing to chromosome breakage and loss probably occurs in haematopoietic cells permitting chromosome 7 loss and progression to clonal malignancy as a secondary event.

A family inheriting different subtypes of acute myelogenous leukemia

Rare inherited cancer syndromes have proven invaluable for the identification of genes involved in the more frequent corresponding noninherited cases. We report on a family with an adult onset, incompletely penetrant, autosomal dominant syndrome of myelodysplasia and acute myelogenous leukemia, affecting at least eight, and probably ten, individuals from three generations. The patients have developed leukemias differing in morphologic subtype, tumor cytogenetics, and abruptness of presentation. Some have presented with acute onset and others with protracted myelodysplasia. This family does not have an unusual incidence of other malignancies; however, one person at 50% risk of inheriting this gene developed atypical mycobacterium infection in the absence of leukemia, but also without appreciable risk factors for acquired deficiencies in cellular immunity. Features common to affected family members, including the individual with mycobacterium infection, are the early presence in the bone marrow of red cell and platelet maturation defects. A search for mutations in diseased marrows fails to detect abnormalities of p53 or N-ras. Two of the affected family members, third degree relatives, have co-inherited a constitutional chromosomal banding variation of 9p21-22, potentially suggesting linkage to this locus. The variable penetrance and expressivity of this syndrome support a multistep model of leukemia evolution, in which the gene defined by this family's syndrome is the signal step.

Familial myelodysplastic syndrome with onset late in life

A family is described in which three, and possibly four members, namely, the propositus, two paternal uncles, and possibly his paternal grandfather, developed a myelodysplastic syndrome (MDS) after the age of 60 years. This late onset resembles sporadic cases which are commoner in older age, rather than the previously reported familial cases most of whom have been children or young adults. The three affected members had megaloblastoid bone marrows with an increased proportion of bone marrow blasts and developed progressive bone marrow failure without leukemic transformation. The propositus showed a dramatic but temporary response to GM-CSF therapy but eventually became unresponsive with a marked increase in bone marrow reticulin and reduction in hemopoietic elements. Affected members had no recognisable bone marrow cytogenetic abnormality but the pattern of inheritance and similarity in clinical features suggest an inherited genetic defect which predisposes to the development of MDS.

Myelodysplastic syndromes in childhood--classification, epidemiology, and treatment

Much of the applied terminology of myelodysplastic syndromes (MDS) in childhood is confusing and not mutually exclusive. It is therefore proposed that the FAB classification of MDS is used in children in order to improve diagnostic precision and to facilitate epidemiologic, clinical, and therapeutic comparisons. The true incidence of childhood MDS is unknown but the rate may approximate the incidence of acute myelogenous leukemia. A pooled analysis of eight larger series representing 110 children less than 15 years old at diagnosis with de novo MDS classified according to the FAB recommendations showed that the more aggressive subtypes dominated, which partly may reflect that the less advanced cases are underdiagnosed. The median age at presentation was 6.0 years. The male/female ratio was 1.6. Monosomy 7 was the most frequent cytogenetic abnormality. The median survival was 13 months and the probability of survival three years from diagnosis was 16%. Spontaneous remission may be observed very infrequently. Allogeneic bone marrow transplantation (BMT) represents the only potentially curative treatment. The survival rate three years after BMT is about 50%. Major differences between childhood and adult MDS exist with respect to the distribution of FAB subgroups, the rate of progression, and the cytogenetic findings. The literature on MDS in children is still sparse and there is an obvious need for more studies designed to determine the incidence, clinical and laboratory characteristics, the natural course, and the efficacy of contemporary treatment options.

Culture of Mycobacterium kansasii in the blood of an HIV negative patient

A 23 year old man with a congenital myelodysplastic disorder and fibrosing lung disease received treatment with prednisolone. After nine months his condition deteriorated and Mycobacterium kansasii was isolated from blood cultures and lymph node biopsy specimens. He responded to antituberculous treatment. M kansasii has not previously been isolated from the blood stream of HIV negative patients.

Karyotypic analysis in primary myelodysplastic syndromes

Cytogenetics has provided new insights into the biology and pathogenesis of myelodysplastic syndromes. In patients with refractory anemia, it has provided proof of clonality and has helped differentiate chronic myelomonocytic leukemia from chronic myeloid leukemia. As a prognostic tool, cytogenetics has been predictive of duration of survival and leukemic transformation. However, its role as an independent prognostic factor compared with recent prognostic scoring systems remains to be determined. New techniques such as fluorescent in situ hybridization using chromosome-specific DNA probes may expand the usefulness of cytogenetics. The prognostic impact of cytogenetics may not be fully realized until more effective treatments become available.

Chromosome abnormalities in bone marrow of Fanconi anemia patients

We report the clonal chromosome abnormalities of five patients with Fanconi anemia (FA). In one with myelodysplastic syndrome (MDS), an abnormal clone was present in the bone marrow (BM): 47,XY,trp(1)(q32q44), + mar. Two had acute myeloblastic leukemia (AML), one with monosomy 7 and the other with 46,XY,add(1)(p34),del(7)(p13). In the two others without signs of MDS or AML, pseudodiploidy with 46,XX,-5, +8 and 46,XX, +5, -21 were present, respectively. The significance of these abnormalities is discussed.

Bone marrow dysfunctions preceding acute leukemia in children: a clinical study

This is a review of preleukaemic states in children. In a prospective series of 109 children with AML the overt disease was preceded by MDS in 22 cases. Ten of these patients had Down's syndrome. Advanced FAB groups were represented in the series. An important subgroup is the bone marrow monosomy 7 syndrome. Cytogenetic anomalies are common in MDS, and multiple and complicated abnormalities develop in nearly all patients with progressing disease. Some children die before transformation to overt ANLL. Transformation usually occurs, few children survive. With cytostatic treatment the risk of irreversible aplasia is great. The choice of schedule should therefore be carefully considered. Bone marrow transplantation has proved beneficial in a number of cases, but these are still quite few. The dysfunction of the bone marrow preceding ALL is due to transient aplastic anaemia--spontaneous remission--overt ALL, often FAB type L1, immunophenotype CALLA. The ALL reacts to the same treatment as de novo ALL of the same type and the prognosis is the same.

Myelodysplasia and leukemia syndrome with monosomy 7: a genetic perspective

Acquired monosomy 7 is a frequent finding in myelodysplastic syndromes, including acute myelogenous leukemia. A subset of these patients has been described with an apparently distinct condition: myelodysplasia and leukemia syndrome with monosomy 7 (MLSM7). We report 2 brothers, 3 and 5 years of age, with MLSM7 and review other reports of familial occurrence. Genetic factors appear to be important in the cause of MLSM7, but the reported families do not fit neatly into any monogenic pattern. Recognition of the frequently familial nature of this condition requires hematological evaluation and genetic counseling for the families of patients with MLSM7.

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.