scholarly journals When Should We Think of Myelodysplasia or Bone Marrow Failure in a Thrombocytopenic Patient? A Practical Approach to Diagnosis

2021 ◽  
Vol 10 (5) ◽  
pp. 1026
Author(s):  
Nicolas Bonadies ◽  
Alicia Rovó ◽  
Naomi Porret ◽  
Ulrike Bacher

Thrombocytopenia can arise from various conditions, including myelodysplastic syndromes (MDS) and bone marrow failure (BMF) syndromes. Meticulous assessment of the peripheral blood smear, identification of accompanying clinical conditions, and characterization of the clinical course are important for initial assessment of unexplained thrombocytopenia. Increased awareness is required to identify patients with suspected MDS or BMF, who are in need of further investigations by a step-wise approach. Bone marrow cytomorphology, histopathology, and cytogenetics are complemented by myeloid next-generation sequencing (NGS) panels. Such panels are helpful to distinguish reactive cytopenia from clonal conditions. MDS are caused by mutations in the hematopoietic stem/progenitor cells, characterized by cytopenia and dysplasia, and an inherent risk of leukemic progression. Aplastic anemia (AA), the most frequent acquired BMF, is immunologically driven and characterized by an empty bone marrow. Diagnosis remains challenging due to overlaps with other hematological disorders. Congenital BMF, certainly rare in adulthood, can present atypically with thrombocytopenia and can be misdiagnosed. Analyses for chromosome fragility, telomere length, and germline gene sequencing are needed. Interdisciplinary expert teams contribute to diagnosis, prognostication, and choice of therapy for patients with suspected MDS and BMF. With this review we aim to increase the awareness and provide practical approaches for diagnosis of these conditions in suspicious cases presenting with thrombocytopenia.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3709-3709
Author(s):  
Lana Vukadin ◽  
Jung-Hyun Kim ◽  
Tara Bly Hackwelder ◽  
Nathan Ungerleider ◽  
Erik Flemington ◽  
...  

Precise regulation of transcription and RNA splicing is critical for controlling hematopoietic cell fate determination and lineage differentiation. Alteration of expression of lineage-specific transcription factors and several core spliceosome components in hematopoietic malignancies highlight the significance of abnormal transcription and RNA splicing as disease-causing factors. Our group previously demonstrated that SON, a large nuclear speckle protein possessing dual abilities to bind both DNA and RNA, functions as a splicing factor as well as a transcriptional repressor. We recently identified heterozygous loss-of-function mutations in the SON gene from children with intellectual disability and developmental delay often with a broad spectrum of other congenital anomalies. The disorder caused by SON haploinsufficiency has been designated as ZTTK syndrome (Zhu-Tokita-Takenouchi-Kim syndrome; OMIM #617140). The majority of the mutations found in these patients are frameshift or nonsense mutations which cause degradation of the mutation-bearing transcript. While the most prominent features of these patients are brain malformations and musculoskeletal abnormalities, we identified various hematological disorders from children with ZTTK syndrome. Notable symptoms include bone marrow failure, severe anemia, immunoglobulin deficiency, thalassemia, polycythemia, polycythemia vera, stroke due to blood clots, and leukocytopenia. Apart from the ZTTK syndrome, SON is known to be upregulated in acute myeloid leukemia (AML) patients and is correlated to altered hematopoietic differentiation. To investigate how altered SON expression affects hematopoiesis, we generated a mouse line with the Son gene deleted specifically in the hematopoietic lineage. Homozygous deletion of Son in hematopoietic lineage led to embryonic lethality, indicating that SON expression in blood cells is indispensable during development. Mice with heterozygous deletion of Son in the hematopoietic lineage were viable and born without notable defects or sign of diseases. However, there is a significant decrease in bone marrow cellularity in the mice with heterozygous deletion of Son. Furthermore, Son haploinsufficiency decreased the size of the lineage negative (Lin-) cell population and short-term hematopoietic stem cell (ST-HSC) population with a concurrent increase in megakaryocyte/erythrocyte lineage-biased multipotent progenitors (MPP2) within hematopoietic stem/progenitor cells. These findings suggest that the level of Son expression potentially affects stem cell maintenance and MPP lineage bias, and the distortion of the subpopulation balance within hematopoietic stem/progenitors is possibly linked to multiple hematological disorders. Our ongoing analyses of hematopoiesis and gene expression changes using this mouse model will expand our knowledge about the role of SON in several hematological disorders and benefit clinical practice for ZTTK syndrome patients. Disclosures No relevant conflicts of interest to declare.


Leukemia ◽  
2021 ◽  
Author(s):  
Melvin E. Thomas ◽  
Sherif Abdelhamed ◽  
Ryan Hiltenbrand ◽  
Jason R. Schwartz ◽  
Sadie Miki Sakurada ◽  
...  

AbstractPediatric myelodysplastic syndromes (MDS) are a heterogeneous disease group associated with impaired hematopoiesis, bone marrow hypocellularity, and frequently have deletions involving chromosome 7 (monosomy 7). We and others recently identified heterozygous germline mutations in SAMD9 and SAMD9L in children with monosomy 7 and MDS. We previously demonstrated an antiproliferative effect of these gene products in non-hematopoietic cells, which was exacerbated by their patient-associated mutations. Here, we used a lentiviral overexpression approach to assess the functional impact and underlying cellular processes of wild-type and mutant SAMD9 or SAMD9L in primary mouse or human hematopoietic stem and progenitor cells (HSPC). Using a combination of protein interactome analyses, transcriptional profiling, and functional validation, we show that SAMD9 and SAMD9L are multifunctional proteins that cause profound alterations in cell cycle, cell proliferation, and protein translation in HSPCs. Importantly, our molecular and functional studies also demonstrated that expression of these genes and their mutations leads to a cellular environment that promotes DNA damage repair defects and ultimately apoptosis in hematopoietic cells. This study provides novel functional insights into SAMD9 and SAMD9L and how their mutations can potentially alter hematopoietic function and lead to bone marrow hypocellularity, a hallmark of pediatric MDS.


Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6087-6096 ◽  
Author(s):  
Pekka Jaako ◽  
Johan Flygare ◽  
Karin Olsson ◽  
Ronan Quere ◽  
Mats Ehinger ◽  
...  

Abstract Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia caused by a functional haploinsufficiency of genes encoding for ribosomal proteins. Among these genes, ribosomal protein S19 (RPS19) is mutated most frequently. Generation of animal models for diseases like DBA is challenging because the phenotype is highly dependent on the level of RPS19 down-regulation. We report the generation of mouse models for RPS19-deficient DBA using transgenic RNA interference that allows an inducible and graded down-regulation of Rps19. Rps19-deficient mice develop a macrocytic anemia together with leukocytopenia and variable platelet count that with time leads to the exhaustion of hematopoietic stem cells and bone marrow failure. Both RPS19 gene transfer and the loss of p53 rescue the DBA phenotype implying the potential of the models for testing novel therapies. This study demonstrates the feasibility of transgenic RNA interference to generate mouse models for human diseases caused by haploinsufficient expression of a gene.


2016 ◽  
Vol 8 ◽  
pp. 2016054 ◽  
Author(s):  
Hosein Kamranzadeh fumani ◽  
Mohammad Zokaasadi ◽  
Amir Kasaeian ◽  
Kamran Alimoghaddam ◽  
Asadollah Mousavi ◽  
...  

Background & objectives: Fanconi anemia (FA) is a rare genetic disorder caused by an impaired DNA repair mechanism which leads to an increased tendency toward malignancies and progressive bone marrow failure. The only curative management available for hematologic abnormalities in FA patients is hematopoietic stem cell transplantation (HSCT). This study aimed to evaluate the role of HSCT in FA patients.Methods: Twenty FA patients with ages of 16 or more who underwent HSCT between 2002 and 2015 enrolled in this study. All transplants were allogeneic and the stem cell source was peripheral blood and all patients had a full HLA-matched donor.Results: Eleven patients were female and 9 male (55% and 45%). Mean age was 24.05 years. Mortality rate was 50% (n=10) and the main cause of death was GVHD. Survival analysis showed an overall 5-year survival of 53.63% and 13 year survival of 45.96 % among patients.Conclusion: HSCT is the only curative management for bone marrow failure in FA patients and despite high rate of mortality and morbidity it seems to be an appropriate treatment with an acceptable long term survival rate for adolescent and adult group.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1507-1507
Author(s):  
Siobán B. Keel ◽  
Tom Walsh ◽  
Colin Pritchard ◽  
Akiko Shimamura ◽  
Mary-Claire King ◽  
...  

Abstract Accurate and timely diagnosis of inherited bone marrow failure (BMF) and myelodysplastic syndromes (MDS) ensures appropriate clinical management. The correct diagnosis allows appropriate monitoring for both hematopoietic (i.e. clonal evolution and progressive marrow failure) and extra-hematopoietic complications, informs the timing of hematopoietic stem cell transplant, donor selection and transplant regimen planning, and ensures appropriate genetic counseling of family members. Substantial phenotypic overlap among these disorders and the variable expressivity within syndromes complicate their diagnosis based purely on physical exam and standard laboratory testing and provide the rationale for comprehensive genetic diagnostic testing. We report here our initial one-year experience utilizing a targeted capture assay of known inherited BMF/MDS genes for clinical diagnostic purposes at the University of Washington. The assay sequences all exons and 20 base pairs of intronic sequence flanking each exon, as well as several regulatory and intronic regions of specific genes containing known pathogenic variants of 85 known inherited BMF/MDS genes (Zhang M. et al. Haematologica 2016). Between June 2015 and July 2016, 81 individual patients were referred for clinical testing (median age: 15 years-old, range: 0.6-76 years-old). For all samples evaluated, median coverage across the 383kb targeted region was 1887X. This depth of coverage enabled identification of all classes of mutations, including point mutations, small indels, copy number variants, and genomic rearrangements. Pathologic mutations in known inherited BMF/MDS genes were identified in 12 of 82 (14.6%) individuals (median age 13 years-old, range: 1.25-43 years-old) across a broad number of genes and of multiple classes including copy number variants (Table). Among the twelve patients with pathogenic mutations in inherited BMF/MDS genes, genetic testing was consistent with the prior clinical diagnoses of eight patients, including two Fanconi anemia patients subtyped as complementation group A, one of whom demonstrated reversion to wild-type resulting in mosaicism in the peripheral blood. Importantly, four patients carried no specific inherited BMF/MDS diagnosis prior to testing and were found to have pathogenic mutations in RPS10, RTEL1 and RUNX1 (ID 005, 008, 009, 010), suggesting additional diagnostic value to a multiplexed genetic approach in the clinical setting. Detailed clinical information was available for nine of the patients diagnosed with pathogenic mutations, two of whom have or will undergo a sibling or haploidentical hematopoietic stem cell transplantation (009 and 012, respectively) and thus genetic testing informed donor selection. To improve diagnostic accuracy, we are now updating the capture design to include newly discovered inherited BMF/MDS genes and intronic regions to optimize copy number variant detection. We are additionally pursuing CLIA-certified RNA analyses to characterize whether several variants bioinformatically predicted to affect splicing are functionally deleterious. Next-generation sequencing for mutations involved in hereditary marrow failure and MDS may also become increasingly important in the context of precision-medicine in which germline mutations are unexpectedly identified in somatic testing. Disclosures No relevant conflicts of interest to declare.


2014 ◽  
Vol 97 (12) ◽  
pp. e75-e77 ◽  
Author(s):  
Mathieu Meunier ◽  
Anne-Claire Manez ◽  
Aliénor Xhaard ◽  
Régis Peffault de Latour ◽  
Flore Sicre de Fontbrune ◽  
...  

Blood ◽  
2000 ◽  
Vol 95 (2) ◽  
pp. 700-704 ◽  
Author(s):  
Kimberly A. Gush ◽  
Kai-Ling Fu ◽  
Markus Grompe ◽  
Christopher E. Walsh

Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, congenital anomalies, and a predisposition to malignancy. FA cells demonstrate hypersensitivity to DNA cross-linking agents, such as mitomycin C (MMC). Mice with a targeted disruption of the FANCC gene (fancc −/− nullizygous mice) exhibit many of the characteristic features of FA and provide a valuable tool for testing novel therapeutic strategies. We have exploited the inherent hypersensitivity offancc −/− hematopoietic cells to assay for phenotypic correction following transfer of the FANCC complementary DNA (cDNA) into bone marrow cells. Murine fancc −/− bone marrow cells were transduced with the use of retrovirus carrying the humanfancc cDNA and injected into lethally irradiated recipients. Mitomycin C (MMC) dosing, known to induce pancytopenia, was used to challenge the transplanted animals. Phenotypic correction was determined by assessment of peripheral blood counts. Mice that received cells transduced with virus carrying the wild-type gene maintained normal blood counts following MMC administration. All nullizygous control animals receiving MMC exhibited pancytopenia shortly before death. Clonogenic assay and polymerase chain reaction analysis confirmed gene transfer of progenitor cells. These results indicate that selective pressure promotes in vivo enrichment offancc-transduced hematopoietic stem/progenitor cells. In addition, MMC resistance coupled with detection of the transgene in secondary recipients suggests transduction and phenotypic correction of long-term repopulating stem cells.


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