Genetic Predisposition to Myelodysplastic Syndrome in Clinical Practice

The role of genetic factors in pediatric myelodysplastic syndromes with different outcomes

BACKGROUND

Pediatric myelodysplastic syndromes (MDS) are rare disorders with an unrevealed pathogenesis. Our aim is to explore the role of genetic factors in the pathogenesis of MDS in children with different outcomes and to discover the correlation between genetic features and clinical outcomes as well as disease characteristics.

METHODS

We conducted an analysis of archived genetic data from 26 patients diagnosed with pediatric MDS at our institution between 2015 and 2021, examining the association between different genetic characteristics and clinical manifestations as well as prognosis. Additionally, We presented three cases with distinct genetic background and outcomes as examples to elaborate the role of genetic factors in pediatric MDS with different prognoses.

RESULTS

Genetic variations were detected in 13 out of the 26 patients, including 8 patients with co-occurrence of somatic and germline mutations (CSGMs) and 5 patients with somatic mutations alone. Our analysis revealed that advanced MDS (4/8, 50% vs. 1/5, 20% and 4/11, 36.4%), PD (3/8, 37.5% vs. 1/5, 20% and 1/11 9.1%), and TD (6/8, 75% vs. 2/5, 40% and 2/11, 18.2%) were more common in patients with CSGMs than those with somatic mutations alone or without any mutations. We also found out in our study that 8 patients with CSGMs had evidently different clinical outcomes, and we presented 3 of them as examples for elaboration. Case 1 with germline and somatic mutations of unknown significance had a relatively slow disease course and a good prognosis. Case 2 with compound heterozygous germline SBDS variants and somatic mutations like del20q had a stable disease course and a reversed outcome. Case 3 with a germline GATA2 variant and somatic mutations including - 7 had a rapidly progressive disease course and a worst prognosis.

CONCLUSION

Our findings indicate that genetic background of pediatric MDS is closely linked with disease characteristics as well as outcomes and that CSGMs may lead to disease progression. It should be emphasized that the interaction between certain germline variants and somatic mutations, such as SBDS and del20q, may result in hematopoietic stem cell adaptation (improved hematopoiesis) and reversed clinical outcomes, which can facilitate the development of targeted therapy.

New-Onset Monosomy 7-Induced Pancytopenia in a 66-Year-Old Woman

Myelodysplastic syndrome (MDS) is characterized by failure to initiate hematopoiesis or impaired maturation of cells, often presenting with pancytopenias with or without associated fatigue, infections, or inappropriate bleeding and bruising. Karyotype analyses of MDS patients commonly show deletion of the q arm of chromosome 7, suggesting loss of this region is likely implicated in the insufficient hematopoiesis seen in MDS. The predisposition to deletion of 7q is commonly inherited, with clinical presentation in early childhood associated with pancytopenia or hematological malignancy. In this case, we present a 66-year-old female who was incidentally found to be pancytopenic in the emergency department while being evaluated for dyspnea, with a bone marrow biopsy later confirming a diagnosis of MDS with monosomy 7. Sporadic loss of 7q can occur at any stage in life without any family history of hematological disease. Our patient has no known personal or family history of MDS, with normal blood counts during hospitalization three years prior, suggesting de novo loss of 7q occurring at greater than 60 years of age.

Clonal evolution in inherited marrow failure syndromes predicts disease progression

Progression to myelodysplastic syndromes (MDS) and acute myeloid leukemia is one of the most serious complications of the inherited bone marrow failure and MDS-predisposition syndromes. Given the lack of predictive markers, this risk can also be a source of great uncertainty and anxiety to patients and their providers alike. Recent data show that some acquired mutations may provide a window into this risk. While maladaptive mechanisms, such as monosomy 7, are associated with a high risk of leukemogenesis, mutations that offset the inherited defect (known as somatic genetic rescue) may attenuate this risk. Somatic mutations that are shared with age-acquired clonal hematopoiesis mutations also show syndrome-specific patterns that may provide additional data as to disease risk. This review focuses on recent progress in this area with an emphasis on the biological underpinnings and interpretation of these patterns for patient care decisions.

Progress toward Better Treatment of Therapy-Related AML

Therapy-related acute myeloid leukemia (t-AML) comprises 10-20% of all newly diagnosed cases of AML and is related to previous use of chemotherapy or ionizing radiotherapy for an unrelated malignant non-myeloid disorder or autoimmune disease. Classic examples include alkylating agents and topoisomerase II inhibitors, whereas newer targeted therapies such as poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors have emerged as causative agents. Typically, t-AML is characterized by adverse karyotypic abnormalities and molecular lesions that confer a poor prognosis. Nevertheless, there are also cases of t-AML without poor-risk features. The management of these patients remains controversial. We describe the causes and pathophysiology of t-AML, putting emphasis on its mutational heterogeneity, and present recent advances in its treatment including CPX-351, hypomethylating agent plus venetoclax combination, and novel, molecularly targeted agents that promise to improve the cure rates. Evidence supporting personalized medicine for patients with t-AML is presented, as well as the authors' clinical recommendations.

Hematopoietic Cell Transplantation in the Management of Myelodysplastic Syndrome: An Evidence-Based Review from the American Society for Transplantation and Cellular Therapy Committee on Practice Guidelines

The sole curative therapy for myelodysplastic syndrome (MDS) is allogeneic hematopoietic cell transplantation (HCT). Here this therapeutic modality is reviewed and critically evaluated in the context of the evidence. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the recommendations. A panel of MDS experts comprising transplantation and nontransplantation physicians developed consensus treatment recommendations. This review summarizes the standard MDS indications for HCT and addresses areas of controversy. Recent prospective trials have confirmed that allogeneic HCT confers survival benefits in patients with advanced or high-risk MDS compared with nontransplantation approaches, and the use of HCT is increasing in older patients with good performance status. However, patients with high-risk cytogenetic or molecular mutations remain at high risk for relapse. It is unknown whether administration of novel therapies before or after transplantation may decrease the risk of disease relapse in selected populations. Ongoing and future studies will investigate revised approaches to disease risk stratification, patient selection, and post-transplantation approaches to optimize allogeneic HCT outcomes for patients with MDS.

Myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a family of myeloid cancers with diverse genotypes and phenotypes characterized by ineffective haematopoiesis and risk of transformation to acute myeloid leukaemia (AML). Some epidemiological data indicate that MDS incidence is increasing in resource-rich regions but this is controversial. Most MDS cases are caused by randomly acquired somatic mutations. In some patients, the phenotype and/or genotype of MDS overlaps with that of bone marrow failure disorders such as aplastic anaemia, paroxysmal nocturnal haemoglobinuria (PNH) and AML. Prognostic systems, such as the revised International Prognostic Scoring System (IPSS-R), provide reasonably accurate predictions of survival at the population level. Therapeutic goals in individuals with lower-risk MDS include improving quality of life and minimizing erythrocyte and platelet transfusions. Therapeutic goals in people with higher-risk MDS include decreasing the risk of AML transformation and prolonging survival. Haematopoietic cell transplantation (HCT) can cure MDS, yet fewer than 10% of affected individuals receive this treatment. However, how, when and in which patients with HCT for MDS should be performed remains controversial, with some studies suggesting HCT is preferred in some individuals with higher-risk MDS. Advances in the understanding of MDS biology offer the prospect of new therapeutic approaches.

The effect of decitabine-combined minimally myelosuppressive regimen bridged allo-HSCT on the outcomes of pediatric MDS from 10 years' experience of a single center

Background

Myelodysplastic syndrome (MDS) is a rare disease in children and the treatment option before the allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rarely reported. Our main objective was to report our single-center experience with the DNA-hypomethylating agent, decitabine-combined minimally myelosuppressive regimen (DAC + MMR) bridged allo-HSCT in children with MDS.

Methods

Twenty-eight children with de novo MDS who underwent allo-HSCT between 2011 and 2020 were enrolled. Patients were divided into subgroups (refractory cytopenia of childhood [RCC] and advanced MDS [aMDS]) and treated by HSCT alone or pre-transplant combination treatment based on risk stratification. The patients’ clinical characteristics, treatment strategies and outcomes were retrospectively evaluated.

Results

Twenty patients with aMDS had received pre-transplant treatment (three were treated with decitabine alone, thirteen with DAC + MMR, and four with acute myeloid leukemia type [AML-type] induction therapy). DAC + MMR was well tolerated and the most common adverse events were myelosuppression and gastrointestinal reaction. DAC + MMR had shown an improved marrow complete remission (mCR) compared with AML-type chemotherapy (13/13, 100% versus 2/4, 50%, P = 0.044). The median follow-up for total cohort was 53.0 months (range, 2.3-127.0 months) and the 4-year overall survival (OS) was 71.4 ± 8.5%. In the subgroup of aMDS, pretreatment of DAC + MMR resulted in a much better survival rate than AML-type chemotherapy (84.6 ± 10.0% versus 0.0 ± 0.0%, P < 0.001).

Conclusions

The DAC + MMR bridged allo-HSCT may be recommended as a novel and effective approach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03376-1.

How low risk are low risk myelodysplastic syndromes?

INTRODUCTION

Risk stratification is crucial to the appropriate management of many diseases, but in patients with myelodysplastic syndromes (MDS), for whom expected survival can vary greatly, accurate disease prognostication is especially important. This is further supported by a relative lack of therapies in MDS, and thus we must prognosticate carefully and accurately. Currently, patients with MDS are often grouped into higher-risk (HR) versus lower-risk (LR) disease using clinical prognostic scoring systems, but these systems have limitations.

AREAS COVERED

The authors reviewed the literature on diagnostics, prognostics, therapeutics and outcomes in MDS. Factors such as disease etiology, specific clinical characteristics, or molecular genetic information not captured in the international prognostic scoring system revised IPSS-R can alter risk stratification, and identify a subset of LR-MDS patients who actually behave more like HR-MDS.

EXPERT OPINION

This review will describe the current identification and management of patients with LR MDS disease whose condition is likely to behave in a less favorable manner than predicted by the IPSS-R. The authors comment on clinical and molecular features which are believe to upstage a patient from lower to higher risk disease.

Incidence and Outcomes of Respiratory Failure After Non-Myeloablative Related Haploidentical Blood or Marrow Transplant

BACKGROUND

Respiratory failure is a devastating complication of allogenic blood or marrow transplant (BMT). Prior data suggest 20% and 15% of BMT patients develop respiratory failure and ARDS, respectively. Non-myeloablative (NMA) haploidentical BMT allows donor pool expansion and may decrease complications. Incidence, outcomes, and risk factors for respiratory failure after NMA haploidentical BMT are unknown.

RESEARCH QUESTION

Determine the incidence of respiratory failure after NMA haploidentical BMT and explore outcomes and risk factors for respiratory failure.

STUDY DESIGN AND METHODS

Single-center, retrospective study of all patients > 18 years old undergoing NMA haploidentical BMT from 2004-2016. The primary outcome was respiratory failure (high-flow nasal cannula oxygen, non-invasive ventilation [NIV], or invasive mechanical ventilation [IMV]) within 2 years after BMT. Respiratory failure incidence is reported as incidence rate ratios (IRR) with 95% confidence intervals. Unadjusted and multivariable Cox proportional hazards models with adjustment for a priori identified patient-level characteristics were used. Results are presented as hazard ratios (HR) with 95% CIs.

RESULTS

520 patients underwent NMA haploidentical BMT; 82 (15.8%) developed respiratory failure (IRR 0.114/person-year) at a median of 0.34 years (25^th, 75^th percentiles 0.06, 0.75 years) after BMT. Older age (HR 1.04, 1.02, 1.07), transplant for MDS (HR 1.99, 1.07, 3.72), and parent donor (HR 3.49, 1.32, 9.26) were associated with increased risk of respiratory failure; higher pre-transplant DLCO (% pred) was associated with lower risk (HR 0.98, 0.77, 0.99). Sixty-one (11.7%) patients required IMV; 30 were successfully extubated. Only 37 (7%) patients had ARDS. Of the 82 with respiratory failure, 43 (52.4%) and 61 (77.2%) died during index hospitalization and by 2 years, respectively. Only 40 (49%) had non-relapse mortality.

INTERPRETATION

Incidence of respiratory failure and ARDS after NMA haploidentical BMT is modest at 15% by 2 years after transplant. Despite successful extubation in more than 50% of patients, respiratory failure, regardless of cause, is associated with a high rate of death by 2 years, from both relapse and non-relapse causes. Age, BMT for MDS, parental donor, and pre-transplant DLCO were risk factors for respiratory failure.

Lower risk but high risk

Risk stratification is crucial to the appropriate management of most cancers, but in patients with myelodysplastic syndromes (MDS), for whom expected survival can vary from a few months to more than a decade, accurate disease prognostication is especially important. Currently, patients with MDS are often grouped into higher-risk (HR) vs lower-risk (LR) disease using clinical prognostic scoring systems, but these systems have limitations. Factors such as molecular genetic information or disease characteristics not captured in the International Prognostic Scoring System-Revised (IPSS-R) can alter risk stratification and identify a subset of patients with LR-MDS who actually behave more like those with HR-MDS. This review describes the current identification and management of patients with LR-MDS whose condition is likely to behave in a less favorable manner than predicted by the IPSS-R.

The clinical and functional effects of TERT variants in myelodysplastic syndrome

Germline pathogenic TERT variants are associated with short telomeres and an increased risk of developing myelodysplastic syndrome (MDS) among patients with a telomere biology disorder. We identified TERT rare variants in 41 of 1514 MDS patients (2.7%) without a clinical diagnosis of a telomere biology disorder who underwent allogeneic transplantation. Patients with a TERT rare variant had shorter telomere length (P < .001) and younger age at MDS diagnosis (52 vs 59 years, P = .03) than patients without a TERT rare variant. In multivariable models, TERT rare variants were associated with inferior overall survival (P = .034) driven by an increased incidence of nonrelapse mortality (NRM; P = .015). Death from a noninfectious pulmonary cause was more frequent among patients with a TERT rare variant. Most variants were missense substitutions and classified as variants of unknown significance. Therefore, we cloned all rare missense variants and quantified their impact on telomere elongation in a cell-based assay. We found that 90% of TERT rare variants had severe or intermediate impairment in their capacity to elongate telomeres. Using a homology model of human TERT bound to the shelterin protein TPP1, we inferred that TERT rare variants disrupt domain-specific functions, including catalysis, protein-RNA interactions, and recruitment to telomeres. Our results indicate that the contribution of TERT rare variants to MDS pathogenesis and NRM risk is underrecognized. Routine screening for TERT rare variants in MDS patients regardless of age or clinical suspicion may identify clinically inapparent telomere biology disorders and improve transplant outcomes through risk-adapted approaches.

Effect of decitabine and thalidomide on the immunological effect and bone marrow mesenchymal stem cells of patients with myelodysplastic syndrome

OBJECTIVE

This study intended to investigate the therapeutic effect of decitabine and thalidomide on myelodysplastic syndrome (MDS), immunological effect and effective mesenchymal stem cells (MSCs).

METHODS

Altogether 62 patients with MDS diagnosed in our hospital were selected. Patients who received 5-day treatment mainly and received decitabine from the 1^st day to the 5^th day were collected as group A (A), while patients who received thalidomide 1^st to 5^th day as in group A were collected as group B (B). The immunologic effects, blood and bone marrow index levels, clinical effects and adverse reactions of group A and group B before and after intervention were observed.

RESULTS

Th17 in the two groups after intervention were evidently lower than that before intervention, and the decrease of Th17 cells in group B after intervention was more obvious than that in group A (P<0.001). Th22 cells in the two groups after intervention were evidently down-regulated compared with those before intervention, and the down-regulation of Th17 cells in group B after intervention was more obvious than that in group A (P<0.001). However, compared with group A, the levels of CD3+, CD4+, CD4+/CD8+ in serum of group B increased more obviously and CD8+ decreased more obviously after intervention. The white blood cell count of group B after intervention was evidently higher than that of group A (P<0.001). The hemoglobin concentration after intervention in group B was evidently higher than that in group A (P<0.001). The platelet count after intervention in group A was evidently higher than that in group B (P<0.001). The total effective rate in group B was evidently higher than that in group A (P<0.05).

CONCLUSION

The combination of decitabine and thalidomide has a better regulatory role in the immunological mechanism and bone marrow mesenchymal stem cells of patients with MDS than the single decitabine therapy on the premise of ensuring clinical efficacy.

Molecular alterations governing predisposition to myelodysplastic syndromes: Insights from Shwachman-Diamond syndrome

Identifying germline mutations responsible for genetic predisposition to myeloid malignancies would be useful in creating opportunities for early intervention. Recent genomic and functional studies in Shwachman-Diamond syndrome (SDS) have deciphered distinct roles for heterozygous mutations in EIF6 and TP53 in alleviating germline genetic stress and a role for biallelic TP53 mutations in malignant progression. This review has summarized evidence for a mechanistic framework underlying SDS that can potentially be applied to the study of other germline myelodysplastic syndromes (MDS) predisposition disorders.