Dataset Information

Increased Frequency of Clonal Hematopoiesis of Indeterminate Potential in Bloom Syndrome Probands and Carriers.

ABSTRACT:

Background

Bloom Syndrome (BSyn) is an autosomal recessive disorder caused by biallelic germline variants in BLM, which functions to maintain genomic stability. BSyn patients have poor growth, immune defects, insulin resistance, and a significantly increased risk of malignancies, most commonly hematologic. The malignancy risk in carriers of pathogenic variants in BLM (BLM variant carriers) remains understudied. Clonal hematopoiesis of indeterminate potential (CHIP) is defined by presence of somatic mutations in leukemia-related genes in blood of individuals without leukemia and is associated with increased risk of leukemia. We hypothesize that somatic mutations driving clonal expansion may be an underlying mechanism leading to increased cancer risk in BSyn patients and BLM variant carriers.

Methods

To determine whether de novo or somatic variation is increased in BSyn patients or carriers, we performed and analyzed exome sequencing on BSyn and control trios.

Results

We discovered that both BSyn patients and carriers had increased numbers of low-frequency, putative somatic variants in CHIP genes compared to controls. Furthermore, BLM variant carriers had increased numbers of somatic variants in DNA methylation genes compared to controls. There was no statistical difference in the numbers of de novo variants in BSyn probands compared to control probands.

Conclusion

Our findings of increased CHIP in BSyn probands and carriers suggest that one or two germline pathogenic variants in BLM could be sufficient to increase the risk of clonal hematopoiesis. These findings warrant further studies in larger cohorts to determine the significance of CHIP as a potential biomarker of aging, cancer, cardiovascular disease, morbidity and mortality.

SUBMITTER: Lin I

PROVIDER: S-EPMC10871368 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature

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Publications

Increased Frequency of Clonal Hematopoiesis of Indeterminate Potential in Bloom Syndrome Probands and Carriers.

Lin Isabella I Wei Angela A Gebo Tsumugi A TA Boutros P C PC Flanagan Maeve M Kucine Nicole N Cunniff C C Arboleda V A VA Chang V Y VY

medRxiv : the preprint server for health sciences 20240206

<h4>Background</h4>Bloom Syndrome (BSyn) is an autosomal recessive disorder caused by biallelic germline variants in <i>BLM,</i> which functions to maintain genomic stability. BSyn patients have poor growth, immune defects, insulin resistance, and a significantly increased risk of malignancies, most commonly hematologic. The malignancy risk in carriers of pathogenic variants in <i>BLM</i> (<i>BLM</i> variant carriers) remains understudied. Clonal hematopoiesis of indeterminate potential (CHIP) i ...[more]

PMID: 38370823

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Project description:Clonally restricted hematopoiesis is a common aging-associated biological state that predisposes to subsequent development of a hematological malignancy or cardiovascular death. Clonal expansion driven by leukemia-associated somatic mutations, such as DNMT3A, ASXL1, or TET2, is best characterized, but oligoclonality can also emerge without recognized leukemia-driver mutations, perhaps as a result of stochastic neutral drift. Murine models provide compelling evidence that a major mechanism of increased cardiovascular mortality in the context of clonal hematopoiesis is accelerated atherogenesis driven by inflammasome-mediated endothelial injury, resulting from proinflammatory interactions between endothelium and macrophages derived from circulating clonal monocytes. Altered inflammation likely influences other biological processes as well. The rate of development of overt neoplasia in patients with clonal hematopoiesis of indeterminate potential (CHIP), as currently defined, is 0.5% to 1% per year. Contributing factors to clonal progression other than acquisition of secondary mutations in hematopoietic cells (ie, stronger leukemia drivers) are incompletely understood. Disordered endogenous immunity in the context of increased proliferative pressure, short telomeres leading to chromosomal instability, an unhealthy marrow microenvironment that favors expansion of clonal stem cells and acquisition of new mutations while failing to support healthy hematopoiesis, and aging-associated changes in hematopoietic stem cells, including altered DNA damage response, an altered transcriptional program, and consequences of epigenetic alterations, are all potential contributors to clonal progression. Clinical management of patients with CHIP includes monitoring for hematological changes and reduction of modifiable cardiovascular risk factors; eventually, it will also likely include anti-inflammatory therapies and targeted approaches to prune emergent dangerous clones.

Project description:BackgroundClonal hematopoiesis of indeterminate potential (CHIP)-associated mutations increase the risk of atherosclerotic heart disease. Comorbidities significantly impact the prognosis of patients with myelodysplastic syndromes (MDS). The objective of this study was to determine the association and impact of CHIP mutations with comorbidities in patients with MDS.MethodsThis retrospective analysis of 566 consecutive patients with MDS was conducted at The University of Texas MD Anderson Cancer Center from August 2013 to December 2016. The 27-item Adult Comorbidity Evaluation (ACE-27) scale was used to assess the severity of comorbid conditions. Next-generation sequencing was used to detect the presence of CHIP mutations in bone marrow aspirates. Spearman correlations and logistic regression analyses were used to determine the association between mutations and comorbidities.ResultsMutations in the genes tet methylcytosine dioxygenase 2 (TET2), ASXL transcriptional regulator 1 (ASXL1), DNA methyltransferase 3α (DNMT3A), Janus kinase 2 (JAK2), and tumor protein 53 (TP53) were noted in 20%, 18%, 9%, 2%, and 21% of patients, respectively. Patients with DNMT3A and JAK2 mutations had higher likelihoods of a prior history of myocardial infarction (odds ratio, 2.62; P = .03) and veno-occlusive disease (odds ratio, 6.48; P = .02), respectively. TP53 mutation was associated with a prior history of malignancy. Patients with TET2 mutation had no association with any comorbidity. A prognostic model including the revised International Prognostic Scoring System classification, the ACE-27 score, and TP53 mutation status (the I-RAT model) predicted median overall survival.ConclusionsIn patients with MDS, the presence of CHIP-associated mutations is associated with comorbidities. DNMT3A and JAK2 mutations were associated with higher likelihoods of prior myocardial infarction and thrombotic events. There was no association between comorbidity and TET2 mutation. Incorporating the revised International Prognostic Scoring System classification with the ACE-27 and TP53 mutation status improved outcome prediction in patients with MDS.

Dataset Information

Increased Frequency of Clonal Hematopoiesis of Indeterminate Potential in Bloom Syndrome Probands and Carriers.

Background

Methods

Results

Conclusion

Publications

Increased Frequency of Clonal Hematopoiesis of Indeterminate Potential in Bloom Syndrome Probands and Carriers.

Similar Datasets

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