SAMD9 and SAMD9L are two interferon-regulated genes located adjacent to each other on chromosome 7q21.2. Germline gain-of-function (GL GOF) mutations in SAMD9/SAMD9L are the genetic cause of MIRAGE syndrome, ataxia-pancytopenia (ATXPC) syndrome, myeloid leukemia syndrome with monosomy 7 (MLSM7), refractory cytopenia of childhood (RCC), transient monosomy 7 in children, SAMD9L-associated autoinflammatory disease (SAAD), and a proportion of inherited aplastic anemia and bone marrow failure syndromes. The myeloid neoplasms associated with GL GOF SAMD9/SAMD9L mutations have been included in the World Health Organization (WHO) 2022 classification. The discovery of SAMD9/SAMD9L-related diseases has revealed some interesting pathobiological mechanisms, such as a high rate of primary somatic compensation, with one of the mechanisms being (transient) monosomy 7 a mechanism also described as \"adaption by aneuploidy.\" The somatic compensation in the blood can complicate the diagnosis of SAMD9/SAMD9L-related disease when relying on hematopoietic tissues for diagnosis. Recently, GL loss-of function (LOF) mutations have been identified in older individuals with myeloid malignancies in accordance with a mouse model of SAMD9L loss that develops a myelodysplastic syndrome (MDS)-like disease late in life. The discovery of SAMD9/SAMD9L-associated syndromes has resulted in a deeper understanding of the genetics and biology of diseases/syndromes that were previously oblivious and thought to be unrelated to each other. Besides giving an overview of the literature, this review wants to also provide some practical guidance for the classification of SAMD9/SAMD9L variants that is complicated by the nonrecurrent nature of these mutations but also by the fact that both GL GOF, as well as loss-of-function mutations, have been identified.

MIRAGE syndrome is a rare multisystemic disorder characterized by various manifestations, such as myelodysplasia, susceptibility to infections, growth retardation, adrenal hypoplasia, genital anomalies, and enteropathy. In the literature, there have been rare cases of dysautonomia. We present a 6.5-year-old girl, who was first admitted to our department with short stature. On follow up, she exhibited multiple endocrinological issues, including transient hypothyroidism, primary hypoparathyroidism and dysautonomia, along with multisystem involvement. Further investigations revealed recurrent moniliasis, low IgM levels, and transient monosomy 7 in the bone marrow. Whole exome sequencing revealed a heterozygous pathogenic variant of SAMD9 (c.2159del; p.Asn720ThrfsTer35). Additional complications observed during follow-up included medullary nephrocalcinosis, hypomagnesemia, hypermagnesiuria, hypophosphatemia, decreased glomerular filtration rate, and nephrotic proteinuria. The patient also developed hyperglycemia, which was managed with low-dose insulin. This case highlights the diagnostic challenges and the diverse phenotypic presentation observed in MIRAGE syndrome.

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.

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Myelodysplastic neoplasms (MDS) are clonal hematopoietic neoplasms. Chromosomal abnormalities (CAs) are detected in 40-45% of de novo MDS and up to 80% of post-cytotoxic therapy MDS (MDS-pCT). Lately, several changes appeared in World Health Organization (WHO) classification and International Consensus Classification (ICC). The novel \'biallelic TP53 inactivation\' (also called \'multi-hit TP53\') MDS entity requires systematic investigation of TP53 locus (17p13.1). The ICC maintains CA allowing the diagnosis of MDS without dysplasia (del(5q), del(7q), -7 and complex karyotype). Deletion 5q is the only CA, still representing a low blast class of its own, if isolated or associated with one additional CA other than -7 or del(7q) and without multi-hit TP53. It represents one of the most frequent aberrations in adults\' MDS, with chromosome 7 aberrations, and trisomy 8. Conversely, translocations are rarer in MDS. In children, del(5q) is very rare while -7 and del(7q) are predominant. Identification of a germline predisposition is key in childhood MDS. Aberrations of chromosomes 5, 7 and 17 are the most frequent in MDS-pCT, grouped in complex karyotypes. Despite the ever-increasing importance of molecular features, cytogenetics remains a major part of diagnosis and prognosis. In 2022, a molecular international prognostic score (IPSS-M) was proposed, combining the prognostic value of mutated genes to the previous scoring parameters (IPSS-R) including cytogenetics, still essential. A karyotype on bone marrow remains mandatory at diagnosis of MDS with complementary molecular analyses now required. Analyses with FISH or other technologies providing similar information can be necessary to complete and help in case of karyotype failure, for doubtful CA, for clonality assessment, and for detection of TP53 deletion to assess TP53 biallelic alterations.

The number of predisposing genes is continuously growing with the widespread availability of DNA sequencing, increasing the prevalence of hematologic malignancies with germline predisposition. Cytogenetic analyses provide an effective approach for the recognition of these malignancies with germline predisposition, which is critical for proper diagnosis, optimal treatment and genetic counseling. Based on the World Health Organization and the international consensus classifications as well as the European LeukemiaNet recommendations, this review first presents an advanced classification of neoplasms with germline predisposition focused on the acquired cytogenetic alterations during leukemogenesis. The various genetic rescue mechanisms and the progression to transformation are then explained. The review also outlines the specific constitutional and somatic cytogenetic aberrations indicative of germline predisposition disorders in B-acute lymphoblastic leukemia (ALL), T-ALL, bone marrow failure syndrome and myeloid neoplasms. An emphasis is made on monosomy 7 in the predisposition field, its frequency and diagnosis impact as well as its various circumstances of occurrence. Lastly, we propose cytogenetic technical recommendations and guidelines for clinical reporting of these specific aberrations.

Most clonal cytogenetic abnormalities of Philadelphia-negative cells (CCA/Ph-) occurring during tyrosine kinase inhibitor (TKI) treatment are transient, and the development of secondary myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) is rare, but the frequency and clinical significance in Japanese patients are still unknown. We herein report four patients who developed CCA/Ph- during TKI therapy and were diagnosed with secondary MDS/AML. The duration from TKI therapy initiation to MDS/AML onset ranged from 3 to 48 months, and the survival ranged from 5 to 84 months. The occurrence of CCA/Ph- with MDS/AML may be associated with a poor prognosis, and careful follow-up is recommended for patients who receive TKI therapy.

We performed sequential molecular analyses of a 75-year-old woman with de novo FLT3-ITD positive acute myeloid leukemia (AML) who had received gilteritinib therapy for 43 months. At the time of diagnosis, her karyotype was normal; however, FLT3-ITD, NPM1, DNMT3A, and IDH2 mutations were detected. She received induction therapy with daunorubicin and cytarabine and achieved hematological complete remission (HCR). After attaining HCR, she underwent consolidation therapy with azacytidine or cytarabine, aclarubicin, and granulocyte-colony stimulating factor. However, AML relapsed eight months after the first HCR. FLT3-ITD and NPM1 mutations were persistently positive, and the patient received gilteritinib therapy. Although the FLT3-ITD clone was not detected during gilteritinib treatment, a clone harboring monosomy 7 and CBL mutations emerged. Bone marrow examinations at 15, 24, and 32 months after gilteritinib treatment revealed multi-lineage blood cell dysplasia without an increase in myeloblasts. After 33 months of treatment, gilteritinib was discontinued for two months because to ileus development, and the FLT3-ITD clone was detected again. Gilteritinib treatment was restarted, and FLT3-ITD became negative. Our analysis demonstrated that: (1) hematopoiesis derived from gilteritinib-resistant clones was generated by long-term gilteritinib treatment, and (2) FLT3-ITD clones regained clonal dominance in the absence of FLT3 inhibition. These findings suggest that gilteritinib affects the selection of dominant clones during clonal hematopoiesis.

Granular acute lymphoblastic leukemia (ALL) is defined by the presence of intracytoplasmic granules in lymphoblastic blasts, mimicking acute myeloblastic leukemia. The disease is extremely rare in adults, and hence, the characteristics thereof are poorly understood. We report a case of a 70-year-old man diagnosed with granular ALL. Bone marrow examination showed blasts with azurophilic granules in the cytoplasm, but immunophenotyping showed B-ALL with aberrant expression of myeloid antigens CD13 and CD33. Karyotyping revealed monosomy 7, and targeted NGS showed DNMT3A mutation, which suggested poor prognosis. Despite conventional chemotherapy treatment, the patient did not achieve complete remission. He declined further chemotherapy treatment and was maintained on only supportive care. This is the first report of adult granular ALL with DNMT3A mutation and monosomy 7.

An 80-year-old Japanese male patient presented to our hospital with complaints of fatigue. His peripheral blood tests revealed pancytopenia with predominant lymphocytes and without blasts. The bone marrow (BM) aspiration was unsuccessful due to a dry tap, and the subsequent BM biopsy revealed hypocellular marrow with fibrosis. He was diagnosed with myelodysplastic syndrome (MDS) with excess blasts (EB)-2 based on CD34-positive cells. The chromosome analysis of the BM revealed monosomy 7, and the SAMD9 W22* mutation was detected (variant allele frequency [VAF] of 51.22%) using next-generation sequencing. An identical mutation was observed in the buccal mucosa (VAF of 50%), which was confirmed as a germline mutation. The SAMD9 gene mutation is reported as one of the causative genes for MIRAGE syndrome and child-onset MDS. The present case was considered a loss-of-function mutation due to the near full-length SAMD9 deletion. This is the first adult case of MDS with SAMD9 W22* as a germline mutation.