OBJECTIVES:Chronic myelomonocytic leukemia (CMML) is defined as a clonal disorder of the myeloid cell lineage, with the characteristic feature being monocytosis. Chromosomal abnormalities are common, but translocations involving chromosome 1p36 are rare. Here, we document a case of CMML that carried an unreported translocation involving t(1;3)(p36.2;p12). The patient showed rapid progression and died within six days post-diagnosis. The 1p36.2 chromosomal region harbors tumor suppressors such as PR domain containing 16 (PRDM16), Tumor Protein 73 (TP73), Cadherin 5 or VE-cadherin (CHD5), and Kinase Family Member 1B (KIF1B), while the 3p12 chromosomal location plays a role in the malignant transformation and disruption of the tumor suppressors, focusing on the genomic instability observed in the case. These changes may partially harbor the capacity to contribute to the pathogenesis of aggressive behaviors in leukemia through failure of apoptosis, chromatin remodeling pathways, and enhanced self-renewal capabilities of stem cells.
OBJECTIVES:Cytogenetic abnormalities play a pivotal role in the diagnosis, classification, risk stratification, and therapeutic decision-making in hematological malignancies. Among these, acute leukemia represents a genetically heterogeneous group in which chromosomal rearrangements and copy number changes significantly influence disease behavior and outcome. The present study describes a comprehensive cytogenetic and fluorescence in situ hybridization (FISH) analysis of 22 patients diagnosed with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML) in blast crisis. Conventional karyotyping and targeted FISH probes were employed to identify recurrent and rare chromosomal abnormalities, with a special emphasis on inv(16) (p13.1q22), MLL rearrangements, and complex karyotypes. Our findings highlight the indispensable role of integrating cytogenetics and FISH in routine diagnostic workflows, especially in cases with cryptic rearrangements or subclonal abnormalities, thereby underscoring their clinical and prognostic significance.
OBJECTIVES:Laboratory genetic counselors (GCs) in cytogenetics oversee a laboratory stewardship (LS) program to review the appropriateness of incoming test orders, which saves both time and healthcare resources. This is especially important for familial cytogenetic testing performed after proband genomic testing, since appropriate testing methodology may vary between families and among family members. We describe three inappropriate orders for familial cytogenetic testing performed after proband genomic testing that were identified and corrected because of the LS process at ARUP Laboratories. Review of familial testing using an LS program avoids false-negative results in at-risk relatives and shortens the time to provide accurate results, enabling relatives to make informed clinical management decisions. This series highlights the importance of seeking genetic advice prior to submitting familial testing samples and including the proband's test results to help the laboratory confirm the appropriateness of test orders. Structural variants (SVs) are identified by proband chromosome analysis, genomic microarray (GMA), and genome sequencing. Healthcare providers without specialized genetics expertise may not realize that SVs can be cryptic by karyotype or undetectable by GMA (when balanced), and that standard FISH probes may fail to detect SVs due to FISH probe localization not spanning the abnormality, even when the FISH probe is designed to target the patient's condition. This series illustrates the benefits of a routine laboratory LS program for familial cytogenetic testing, particularly when cryptic SVs are involved.
OBJECTIVES:We describe a case of a 13-year-old male who presented with fatigue, loss of appetite, and weakness. Flow cytometric analysis of the bone marrow aspirate demonstrated an abnormal population of myeloid blasts, comprising approximately 48% of total events, suggesting acute myeloid leukemia (AML). The cells express CD45(dim+), CD34(+), CD117(+), CD33(+), CD13(dim+), HLADR(+), CD38(+), CD123(weak+), CD11b(weak+), CD15(dim+), CD64(variable+), CD14(weak+), CD4(dim+), CD56(variable+), CD7(weak+), CD11c(+), CD65(dim+), CD9(-), and MPO(+) suggesting acute myeloid leukemia. This particular pattern with a t(8;21) is seen in 15-18% of AML cases. Although it's in the favorable risk stratification category (NCCN Clinical Practice Guidelines 2023), the presence of complex abnormalities, including 1q+, deletion of 12p, and a der(12;22), suggests genomic instability and poor prognosis. The patient died six months post-transplant.
OBJECTIVES:Acute lymphocytic leukemia (ALL) is a hematologic malignancy marked by clonal growth of lymphoid precursors within the bone marrow, resulting in disrupted hematopoiesis. Chromosomal abnormalities provide valuable information on the development of ALL and serve as a key indicator of patient outcomes and treatment strategies. Numerous genetic abnormalities can be seen in ALL. Here, we described a case of a 15-year-old patient with B-ALL confirmed through biopsy and immunophenotyping. Conventional cytogenetic and FISH analysis showed t(3;7) with the presence of t(9;22). Translocation t(3;7) is rarely observed and is associated with a worse/ poor prognosis. Hence, the identification of such translocations in patients with B-ALL can aid in patient stratification, personalized medicine, and risk assessment.
OBJECTIVES:Acute erythroid leukemia (AEL), a rare and diagnostically complex subtype of acute leukemia, has undergone significant evolution in its diagnostic criteria since its initial description in 1912 by Copelli. Proper classification requires the integration of clinical history and diagnostic studies, including peripheral blood and bone marrow morphology, flow cytometry, cytogenetic and molecular studies. The latter have significant clinical and prognostic implications. Here, we discuss a case of AEL with a TP53 mutation and highlight the importance of integration of multiple test modalities in the accurate diagnosis of AEL versus acute myeloid leukemia, myelodysplasia- related (AML-MR). Additionally, we provide an overview of AEL and compare diagnostic changes in the WHO-HAEM5 and ICC.
OBJECTIVES:Acute promyelocytic leukemia (APL) is cytogenetically characterized by the t(15;17)(q22;q21) translocation generating the PML::RARA fusion gene. Accurate laboratory diagnosis is essential for disease confirmation and prognostic prediction. In our cytogenetics laboratory, conventional GTG-banded karyotyping and fluorescence in situ hybridization (FISH) are routinely performed for all APL-suspected cases received from the chemotherapy unit of The Gujarat Cancer and Research Institute, Ahmedabad, after bone marrow/IPT requisitions. To document the cytogenetic abnormalities detected in APL-suspected cases using karyotyping and FISH, and to analyze their association with overall patient survival outcomes. This retrospective study included 32 APL-suspected cases referred to our laboratory. Each case underwent conventional cytogenetic analysis and FISH for the PML::RARA fusion. Clinical outcomes (Normal/Recovered, Discharged/Stable, Expired) were obtained from hospital records solely for correlation. Statistical analysis using SPSS included cross-tabulation and chi-square testing to assess the association between FISH status and patient outcomes. FISH detected PML::RARA fusion in 78.1% of cases (25/32), while 21.9% (7/32) exhibited negative or variant fusion patterns. All successful karyotyping studies demonstrated t(15;17), with occasional additional abnormalities. FISH-positive patients showed significantly better recovery rates (60%) compared to none among FISH-negative/variant cases. The association between FISH status and outcome was statistically significant (χ² = 11.165, p = 0.004). Cytogenetic evaluation using karyotyping and FISH provides essential diagnostic and prognostic insight in APL-suspected cases. FISH positivity strongly correlates with favorable outcomes, underscoring its value in routine diagnostic workflows.
OBJECTIVES:A 75-year-old male presented with back pain, abdominal discomfort, and weight loss, and was subsequently found to have a pancreatic head mass. Biopsy confirmed diffuse large B-cell lymphoma (DLBCL), and the patient achieved radiographic remission with chemotherapy. However, fluorescence in situ hybridization (FISH) analysis unexpectedly revealed Philadelphia chromosome-positive (Ph+) cells in the bone marrow and peripheral blood, establishing concurrent chronic myeloid leukemia (CML). Despite targeted therapy for CML, at last follow-up, the patient still has detectable BCR::ABL1. This rare case highlights the diagnostic importance of comprehensive staging and cytogenetic testing, as well as the therapeutic challenge of managing synchronous lymphoid and myeloid neoplasms.
OBJECTIVES:Acute myeloid leukemia (AML) is a blood cancer characterized by the overproduction of myeloid precursors within the bone marrow, resulting in disrupted hematopoiesis. Chromosomal abnormalities provide valuable insights into the development of AML and serve as key indicators of patient outcomes and treatment strategies. Numerous genetic abnormalities can be seen in AML. Here, we describe a case of a 34-year-old patient with AML-M5. Biopsy and immunophenotyping confirmed AML-M5, while conventional cytogenetic and fluorescence in situ hybridization (FISH) analysis revealed trisomy of chromosomes 7 and 12, and an isochromosome (i)(Xq10). Trisomies of such chromosomes and i(Xq10) in combination are rare and carry different prognostic significance. In this case, the patient died within three days of diagnosis, demonstrating a poor prognosis. Hence, identification of such numerical chromosomal abnormalities in AML-M5 can help in patient stratification, tailored medicine, and risk assessment.
OBJECTIVES:Chromosome translocations involving the RUNX1 gene at 21q22 are recurring abnormalities in acute myeloid leukemia (AML). t(8;21)(q22;q22) is the most common translocation involving the RUNX1 gene, which is categorized as an independent type of acute leukemia in the WHO classification system. The translocation results in a frame fusion of RUNX1::RUNX1T1, which is considered to be the pathogenesis of neoplasm development. The present report describes an AML case displaying a t(8;21)(q22;q22)-like translocation by initial chromosome analysis, but subsequent FISH analysis did not show the fusion signals corresponding to the RUNX1::RUNX1T1 fusion gene. Reverse transcriptase polymerase chain reaction (RT-PCR) also failed to identify the formation of the RUNX1::RUNX1T1 fusion gene. Reassessment of chromosome analysis in light of the FISH and RT-PCR data yielded a t(8;21) (q23;q22) translocation.
OBJECTIVES:This case report presents the findings of a genetic analysis using conventional cytogenetics and fluorescence in situ hybridization (FISH) to investigate a chromosomal abnormality in a patient with developmental delay and dysmorphic features. The patient was diagnosed with a 48,XY,t(6;11)(q27;q23) translocation and tetrasomy 21. Chromosomal analysis is essential for the diagnosis and risk stratification of all leukemia patients. Not surprisingly, racial differences in chromosomal aberrations (CA) in hematological malignancies could be found, and CA incidence in leukemia might change over time, possibly due to environmental and lifestyle changes. The t(6;11)(q27;q23) translocation is a significant chromosomal rearrangement linked to acute leukemia, particularly acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). This translocation disrupts normal hematopoietic processes by fusing the KMT2A (MLL) gene on 11q23, a master regulator of gene transcription with the MLLT4 (AF6) gene on 6q27, leading to oncogenic transformation and aggressive disease progression. Conventional cytogenetic analysis revealed the presence of an additional chromosome 21 and a translocation between chromosomes 6 and 11, which were further confirmed by FISH. This case highlights the significance of cytogenetic techniques in identifying complex chromosomal disorders and provides insights into the clinical implications of such abnormalities.
OBJECTIVES:A recent prospective study run by the IDENTIFY project at the U.S. National Institutes of Health (NIH) uncovered occult cancers in pregnant or postpartum women who previously received Non-Invasive Prenatal Testing (NIPT) reports of atypical abnormal/ unreportable results that were discordant with the fetal genotype. Among 107/117 patients enrolled who received a full evaluation, 52 (48.6%) had cancers, mostly lymphomas (31/52), colorectal tumors (9/52), and breast cancer (4/52). These results were gathered through standardized research cfDNA sequencing in peripheral blood and a comprehensive cancer screening protocol. Most of these patients (47/52) showed a sequencing pattern in cfDNA of multiple subchromosomal and/or whole gains and losses in multiple chromosomes (≥3). This pattern was interpreted as a high-risk indicator of cancers. Except for whole-body MRI imaging, which was very effective in discovering tumors (49/101 cases), the rest of the cancer screening was not informative. The whole data strengthen the view that NIPT has clinical value for a preliminary identification of pregnant women who may have hidden malignancies and should be referred for a thorough cancer screening. In addition, a uniform follow-up protocol of comprehensive cancer screening allowed the diagnosis of a substantial number of cancers that otherwise would not have been detected. Overall, these results from IDENTIFY, the first via a prospective study, also represent progress in guidelines for improved identification and management of occult malignancies coexisting with pregnancies.
OBJECTIVES:Hermaphroditism can be triggered by 22q11.2 duplication in 46,XX individuals without SRY, indicating alternate routes regulating sexual differentiation. Hypospadias may be exacerbated by gene overexpression in this area, which may interfere with androgen signaling. Furthermore, located on the 22q13.33 and 22q11.2 regions, respectively, PLXNB2 and CRKL may also be involved in urogenital abnormalities, while SOX10 duplications are associated with sex reversal. The way that TBX1 interacts with the SHH pathway points to an additional role in the development of hypospadias. Despite their contributions, genes such as ZNF74 likely have little effect. Although chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) improve the diagnosis of 22q11.2-associated hermaphroditism, the syndrome's varied expressivity makes clinical evaluation and prediction more difficult. These uncommon rearrangements are caused by nonallelic homologous recombination NAHR between low-copy repeats, which makes diagnosis even more difficult. More study is required to elucidate the underlying mechanisms of these disorders' complicated gene connections and enhance diagnostic precision.
OBJECTIVES:We report the case of a 50-year-old male with acute myeloid leukemia (AML). Chromosome analysis revealed an abnormal karyotype with a t(6;20)(q13;q11.2) and a complex rearrangement leading to an extra derivative chromosome 1 [der(1)(14q32->14p13::1p13->1q44] which was confirmed by metaphase FISH. FISH analysis confirmed an extra copy of 1q25 in 30.5% [61/200] of the nuclei examined. Rearrangements leading to an extra copy of 1q are common in AML, but translocations involving chromosomes 6 and 20 are rarely observed. Both were seen previously in this patient, suggesting persistence of this patient's neoplasm. Only six cases in the literature describe translocations between chromosomes 6 and 20. However, the breakpoints found in our patient [t(6;20)(q13;q11.2)] appear to be unique. Further studies need to be conducted to determine if this is a common/rare abnormality in AML. Also, there was a complex rearrangement involving chromosomes 1 and 14, which was characterized by metaphase FISH, which is still a powerful tool for detecting complex rearrangements in the clinical cytogenetics laboratory.
OBJECTIVES:Chronic myeloid leukemia (CML) is typically characterized by the presence of the BCR-ABL1 fusion gene on chomosome 22 resulting from a t(9;22)(q34;q11.2) translocation. We report a case of a 59-year-old female with CML in the chronic phase, initially presenting with thrombocytosis and diagnosed with t(9;22) via conventional karyotyping and fluorescence in situ hybridization (FISH). Nine years and seven months after the initial diagnosis, despite treatment with standard imatinib mesylate therapy (400 mg daily), conventional cytogenetic analysis revealed the emergence of trisomy 8 and a pericentric inversion of chromosome 16 (inv(16) (p13q22)) in cells that already carried the t(9;22). Bone marrow aspiration and biopsy showed 80% blasts, predominantly expressing myeloid markers CD13, CD33, CD117, along with HLA-DR and CD34. Both FISH and conventional karyotyping confirmed the presence of trisomy 8, inversion of chromosome 16, and t(9;22). Additionally, reverse transcription-polymerase chain reaction (RT-PCR) confirmed the presence of the BCR-ABL fusion gene. The coexistence of these genetic abnormalities is often associated with an aggressive clinical course, rapid disease progression, and chemotherapy resistance. Following disease progression, the patient was treated with a combination of hydroxyurea (500 mg) and decitabine (50 mg), and her tyrosine kinase inhibitor (TKI) therapy was switched to bosutinib (400 mg). Despite these interventions, she developed pleural effusions and lung metastases and ultimately passed away approximately seven months after initiating the new treatment due to relapsed disease and infectious complications.
OBJECTIVES:IgD myeloma is a rare subset of multiple myeloma characterized by the production of monoclonal IgD protein. This subset of myeloma generally has a more severe and aggressive clinical course. The case reported here is of a 61-year-old female with recurrent disease complicated by encephalopathy, myalgia, and extensive skeletal involvement. The bone marrow showed sheets of plasma cells and plasmablasts, with flow cytometry demonstrating a monoclonal population of CD138-positive, lambda-restricted cells. FISH demonstrated a t(11;14)(q13;q32) translocation and a gain of 1q. Despite treatments with daratumumab, bortezomib, lenalidomide, dexamethasone, and autologous stem cell transplant, the patient ultimately expired from streptococcal pneumonia with hypoxic respiratory and subsequent multiorgan failure.
OBJECTIVES:Acute myeloid leukemia (AML) is a heterogeneous disease, indicated by its many conceivable cytogenetic mutations. Hyperdiploidy is a rare abnormality in AML, more prevalent in children than adults, with few other distinguishing associations. Chromosome totals above 49 in AML are very rare (2%). AML with hyperdiploidy can first be categorized as low or high hyperdiploidy (HH) based on modal chromosome number. High hyperdiploidy is then subcategorized into adverse, structural, or numerical HH. Across all three subtypes of HH, gains of chromosomes 8, 13, and 21 are the most frequent. Although the general survival outcomes of HH AML have remained inconsistent across several different studies, prognosis often relies on the modal chromosome number of the patient, with higher numbers having significantly poorer overall survival rates (OS). Here, we present an 80-year-old male patient with AML showing an abnormal karyotype presenting 78 to 81 chromosomes.
OBJECTIVES:The Nobel Assembly of the Karolinska Institute (Sweden) awarded the 2024 Nobel Prize in Physiology or Medicine to Dr. Victor Ambros (University of Massachusetts Chan Medical School, Worcester, United States) and Dr. Gary Ruvkun (Massachusetts General Hospital, Boston, United States). This award recognized their joint discoveries of microRNAs and a novel mechanism of post-transcriptional regulation of gene expression in the worm C. elegans. This revolutionary breakthrough demonstrated first that miRNAs provide a refined control of development in C. elegans targeting mRNAs from distinct genes in an orderly fashion. Subsequent discoveries of many more microRNAs in other organisms across a wide evolutionary tree showed that these molecules and the regulatory mechanism of gene expression that they regulate are conserved throughout evolution. With more studies, these advances also triggered a realization that microRNAs play important roles in various critical biological processes (e.g., cellular growth, differentiation, development, cellular physiology, etc.). Other surveys reported abnormalities in microRNAs connected to multiple human diseases which, in turn, generated research interest in potential treatments focused on faulty microRNAs and their evaluation as potential markers of disease. This Nobel Prize caps nearly three decades of unprecedented advances in RNA research that include similar awards. A 2006 Nobel Prize honored the discovery of RNA interference that was initially described in 1998. The 2023 Nobel Prize paid tribute to the first effective human mRNA vaccines. Both advances generated practical applications of high significance including medical uses in humans. For these reasons, there is hope that in due time it will also be the case with microRNAs given their biological potential and many relevant physiological functions that they control.
OBJECTIVES:The Nobel Prize in Physiology or Medicine for 2023 awarded to Dr. Katalin Karikó and Dr. Drew Weissman recognized their seminal discoveries in nucleoside modifications of messenger RNA that were pivotal to developing the first mRNA vaccines for clinical use in humans. These novel vaccines were key for prophylactic control of a pandemic caused by the new coronavirus SARS-CoV-2 that emerged abruptly in late 2019/early 2020. This breakthrough capped years of previous research in coronaviruses that included SARS- CoV and MERS-CoV associated with earlier human outbreaks, developments of more efficient formulations to deliver nucleic acids in vivo, and applications of a novel mRNA technology to generate a new generation of better vaccines cost-effectively. Such successful outcomes herald a wide range of advances with this highly adaptable mRNA technology. These include vaccines against existing infectious agents of medical significance but also emerging pathogens, cancer immunotherapies, and protein-replacement therapies, while at the same time, other uses are also under active investigation.
OBJECTIVES:16p11.2 deletion syndrome is a rare genetic abnormality that affects an individual's cognitive abilities. 16p11.2 deletion syndrome is characterized by a loss of region 11.2 on chromosome 16, which includes several genes with various functions. Numerous genes linked to this loss are essential for brain function and neurodevelopment. Notably, genes associated with neuronal development, synaptic function, and brain connection have been found inside the deleted region, including KIF22, TAOK2, and ALDOA, as well as approximately 22 to 25 other additional genes. The diverse clinical presentations noted in patients with 16p11.2 deletion syndrome can be ascribed to the intricate interactions among these mutated genes and their influence on multiple cellular processes. The 16p11.2 deletion syndrome is not observable by conventional cytogenetics. Chromosomal microarray studies are recommended to detect this 16p11.2 deletion.
