The Clinical Spectrum, Diagnosis, and Management of GATA2 Deficiency

GATA2 deficiency and hemophagocytic lymphohistiocytosis (HLH): a systematic review of reported cases

PURPOSE

GATA2 deficiency is an autosomal dominant disease that manifests with a range of clinical symptoms, including increased susceptibility to viral, bacterial, and fungal infections. Furthermore, the increased susceptibility to infections in GATA2 deficiency can trigger hemophagocytic lymphohistiocytosis (HLH) in these patients. Our systematic review evaluates reported cases of GATA2 deficiency and HLH in the literature.

METHODS

A systematic review of case reports was conducted following PRISMA 2020 guidelines, encompassing studies retrieved from Ovid MEDLINE ALL, Embase via Ovid SP, Scopus, Web of Science, and Google Scholar from inception until June 14, 2024. This review included studies reporting patients diagnosed with GATA2 deficiency or having a documented history of the condition, who subsequently developed or were concurrently diagnosed with HLH. Various study types were considered, such as case reports, case series, letters to editors, original articles, correspondences, and commentaries, without any restrictions on language.

RESULTS

In our systematic review, 15 studies from 2016 to 2024 were analyzed, encompassing 23 patients with GATA2 deficiency and HLH. the mean (SD) age of patients was 23.48 (10.54) years, ranging from 7 to 57 years. These patients exhibited diverse genetic mutations and a spectrum of infections, particularly Mycobacterium avium (M. avium), Mycobacterium kansasii (M. kansasii), Epstein-Barr virus (EBV), cytomegalovirus (CMV), varicella-zoster virus (VZV), herpes simplex virus (HSV), and influenza A, often leading to HLH. Family histories of GATA2-deficient patients with HLH occasionally reveal confirmed GATA2 mutations or suspicious cases among first-degree relatives. Hematopoietic stem cell transplantation (HSCT) was performed in 8 patients with GATA2 deficiency and HLH. Among them, 6 patients survived post-therapy, while 2 patients died following HSCT. Currently, 1 patient is being considered for HSCT. The overall mortality rate among GATA2 deficiency patients who experienced HLH was 39.13%.

CONCLUSIONS

This systematic review highlights GATA2 deficiency's association with diverse infections triggering HLH, emphasizing early infection management to mitigate mortality risks. This comprehensive analysis contributes to scientific knowledge, offering important insights for clinicians and researchers in diagnosing and managing this rare condition.

Genetic predisposition to myelodysplastic syndrome: Genetic counseling and transplant implications

The development of myelodysplastic syndromes (MDS) is influenced by various genetic predispositions. Several important genes contribute to disease susceptibility. This paper explores common genetic predisposition genes in MDS, including DDX41, CEBPA, and SAMD9/SAMD9L, which are linked to hereditary conditions presenting diagnostic and clinical challenges. It delves into hereditary conditions that affect platelet production and count, such as RUNX1, ETV6, and ANKRD26, detailing their clinical features and how they contribute to an increased risk of MDS. The discussion extends to additional genetic syndromes like GATA2 deficiency, telomere biology disorders, Fanconi anemia, and Li-Fraumeni syndrome, along with new findings on genes like ERG that offer new insights into disease etiology. The importance of genetic counseling in MDS is underscored, outlining its goals, methods for evaluating family history, risk assessment, and the ethical considerations involved. Furthermore, the role of hematopoietic cell transplantation in managing MDS, particularly in patients with germline syndromes, is reviewed, emphasizing the need for optimal donor selection and personalized treatment approaches. This comprehensive overview illustrates the critical role of genetic factors in MDS and highlights the need for continued research and tailored clinical practices to improve patient outcomes.

The CRISPR-Cas System and Clinical Applications of CRISPR-Based Gene Editing in Hematology with a Focus on Inherited Germline Predisposition to Hematologic Malignancies

Clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing has begun to transform the treatment landscape of genetic diseases. The history of the discovery of CRISPR/CRISPR-associated (Cas) proteins/single-guide RNA (sgRNA)-based gene editing since the first report of repetitive sequences of unknown significance in 1987 is fascinating, highly instructive, and inspiring for future advances in medicine. The recent approval of CRISPR-Cas9-based gene therapy to treat patients with severe sickle cell anemia and transfusion-dependent β-thalassemia has renewed hope for treating other hematologic diseases, including patients with a germline predisposition to hematologic malignancies, who would benefit greatly from the development of CRISPR-inspired gene therapies. The purpose of this paper is three-fold: first, a chronological description of the history of CRISPR-Cas9-sgRNA-based gene editing; second, a brief description of the current state of clinical research in hematologic diseases, including selected applications in treating hematologic diseases with CRISPR-based gene therapy, preceded by a brief description of the current tools being used in clinical genome editing; and third, a presentation of the current progress in gene therapies in inherited hematologic diseases and bone marrow failure syndromes, to hopefully stimulate efforts towards developing these therapies for patients with inherited bone marrow failure syndromes and other inherited conditions with a germline predisposition to hematologic malignancies.

Unraveling germline predisposition in hematological neoplasms: Navigating complexity in the genomic era

Genomic advancements have yielded pivotal insights into hematological neoplasms, particularly concerning germline predisposition mutations. Following the WHO 2016 revisions, dedicated segments were proposed to address these aspects. Current WHO 2022, ICC 2022, and ELN 2022 classifications recognize their significance, introducing more mutations and prompting integration into clinical practice. Approximately 5-10% of hematological neoplasm patients show germline predisposition gene mutations, rising with risk factors such as personal cancer history and familial antecedents, even in older adults. Nevertheless, technical challenges persist. Optimal DNA samples are skin fibroblast-extracted, although not universally applicable. Alternatives such as hair follicle use are explored. Moreover, the scrutiny of germline genomics mandates judicious test selection to ensure precise and accurate interpretation. Given the significant influence of genetic counseling on patient care and post-assessment procedures, there arises a demand for dedicated centers offering specialized services.

Germline Variants and Characteristic Features of Hereditary Hematological Malignancy Syndrome

Due to the proliferation of genetic testing, pathogenic germline variants predisposing to hereditary hematological malignancy syndrome (HHMS) have been identified in an increasing number of genes. Consequently, the field of HHMS is gaining recognition among clinicians and scientists worldwide. Patients with germline genetic abnormalities often have poor outcomes and are candidates for allogeneic hematopoietic stem cell transplantation (HSCT). However, HSCT using blood from a related donor should be carefully considered because of the risk that the patient may inherit a pathogenic variant. At present, we now face the challenge of incorporating these advances into clinical practice for patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) and optimizing the management and surveillance of patients and asymptomatic carriers, with the limitation that evidence-based guidelines are often inadequate. The 2016 revision of the WHO classification added a new section on myeloid malignant neoplasms, including MDS and AML with germline predisposition. The main syndromes can be classified into three groups. Those without pre-existing disease or organ dysfunction; DDX41, TP53, CEBPA, those with pre-existing platelet disorders; ANKRD26, ETV6, RUNX1, and those with other organ dysfunctions; SAMD9/SAMD9L, GATA2, and inherited bone marrow failure syndromes. In this review, we will outline the role of the genes involved in HHMS in order to clarify our understanding of HHMS.

ETV6 represses inflammatory response genes and regulates HSPC function during stress hematopoiesis in mice

ETS variant 6 (ETV6) encodes a transcriptional repressor expressed in hematopoietic stem and progenitor cells (HSPCs), where it is required for adult hematopoiesis. Heterozygous pathogenic germline ETV6 variants are associated with thrombocytopenia 5 (T5), a poorly understood genetic condition resulting in thrombocytopenia and predisposition to hematologic malignancies. To elucidate how germline ETV6 variants affect HSPCs and contribute to disease, we generated a mouse model harboring an Etv6R355X loss-of-function variant, equivalent to the T5-associated variant ETV6R359X. Under homeostatic conditions, all HSPC subpopulations are present in the bone marrow (BM) of Etv6R355X/+ mice; however, these animals display shifts in the proportions and/or numbers of progenitor subtypes. To examine whether the Etv6R355X/+ mutation affects HSPC function, we performed serial competitive transplantation and observed that Etv6R355X/+ lineage-sca1+cKit+ (LSK) cells exhibit impaired reconstitution, with near complete failure to repopulate irradiated recipients by the tertiary transplant. Mechanistic studies incorporating cleavage under target and release under nuclease assay, assay for transposase accessible chromatin sequencing, and high-throughput chromosome conformation capture identify ETV6 binding at inflammatory gene loci, including multiple genes within the tumor necrosis factor (TNF) signaling pathway in ETV6-sufficient mouse and human HSPCs. Furthermore, single-cell RNA sequencing of BM cells isolated after transplantation reveals upregulation of inflammatory genes in Etv6R355X/+ progenitors when compared to Etv6+/+ counterparts. Corroborating these findings, Etv6R355X/+ HSPCs produce significantly more TNF than Etv6+/+ cells post-transplantation. We conclude that ETV6 is required to repress inflammatory gene expression in HSPCs under conditions of hematopoietic stress, and this mechanism may be critical to sustain HSPC function.