Journal of the Association of Genetic Technologists最新文献

Objectives: Fluorescent in situ hybridization has been the definitive modality in testing for overexpression of the Human Epidermal Growth Factor Receptor 2 (HER2) for decades to guide the appropriate treatment for cancer patients. In more recent years innovation and new techniques have been developed to supplant or even replace FISH as a standard method for biomarker testing. Alternative testing methods such polymerase chain reaction (PCR), next-generation sequencing (NGS), and other in situ hybridization (ISH)-derived techniques such as chromogenic-ISH (CISH) have been shown in multiple publications to have high concordance with FISH in addition to advantages in economics, logistics and practicality to the point where CISH and derived methods appear to have eclipsed FISH as a testing method of choice after immunohistochemistry (IHC). This review assesses the status of FISH compared to other diagnostic techniques such as IHC, CISH, and less common and/or experimental methods. Also addressed are the updates to the guidelines from the American Society of Clinical Oncology (ASCO), College of American Pathologists (CAP), and National Comprehensive Cancer Network (NCCN) regarding FISH and IHC for HER2 testing with the updates reducing the number of equivocal diagnoses in the latest iteration. Though our findings show a constantly changing technological landscape, FISH remains an important primary tool to guide medical treatment and as a solid foundation to build upon for innovation in cancer research.

Objectives: Patients with Fanconi Anemia (FA) have an increased risk of developing myeloid malignancies, which often precede the diagnosis of FA. We describe a patient with non-specific clinical findings diagnosed with myelodysplastic syndrome (MDS) at 17 years of age. A pathogenic SF3B1 alteration was identified and prompted evaluation for a bone marrow failure syndrome. Chromosomal breakage testing demonstrated an increase in breakage and radial formation; a targeted FA molecular panel identified variants of unknown significance in FANCB and FANCM. To date, reports of pediatric patients, with or without a co-morbid diagnosis of FA, diagnosed with MDS with SF3B1 alteration are rare. We describe a patient with FA diagnosed with MDS with ring sideroblasts and multilineage dysplasia (MDS-RS-MLD, WHO revised 4th edition) with an associated SF3B1 alteration and discuss the new classifications of this entity. In addition, as the knowledge around FA grows, so too does the knowledge about genes associated with FA. We present a novel variant of unknown significance in FANCB, to add to the growing body of literature about genetic alterations identified in individuals with a clinical picture most in keeping with FA.

Objectives: The ribosomal protein S14 (RPS14) gene located at 5q33 codes for a protein involved in ribosomal biogenesis. The RPS14 gene has a length of 5.9 kb of DNA comprising 5 exons and 4 introns. It is possible that RPS14 is involved in the formation of pre-RNA 18s, an intermediate RNA that serves for the formation of the 40S small subunit of the ribosome. RPS14 haploinsufficiency (HI) produces alterations in intermediate RNA levels (pre-RNA 30S/18SE/18S), which are found in del(5q) MDS. In addition, RPS14 haploinsufficiency results in the formation of the MDM2 (double minute mouse E3 ubiquitin ligase)-RP (ribosomal protein) complex that prevents the MDM2-p53 interaction, generating an accumulation of p53 levels. This accumulation produces cell cycle arrest, impaired DNA repair, senescence, and apoptosis. RPS14 haploinsufficiency has been seen in MDS. Altered expression levels of RPS14 have also been reported in glioma, colorectal cancer, hepatocellular carcinoma, breast cancer, renal cell carcinoma, and primary myelofibrosis.

Objectives: Myelodysplastic syndrome with excess blasts-2 (MDS-EB-2) primarily affects adults older than 50 years and confers a worse prognosis with a higher risk of transformation to acute myeloid leukemia (AML) compared to myelodysplastic syndrome (MDS) and MDS with excess blasts-1 (MDS-EB-1). In ordering diagnostic studies for MDS, cytogenetic and genomic studies are vital as they have significant clinical and prognostic implications for the patient. We present a case of a 71-year-old male diagnosed with MDS-EB-2 with a pathogenic loss-of-function TP53 variant and discuss presentation, pathogenesis, and the importance of thorough diagnostic testing through multiple modalities to accurately diagnose and subtype MDS. In addition, we explore a historical overview of the diagnostic criteria of MDS-EB-2 and how it has changed over time from the World Health Organization (WHO) 4th edition in 2008, the WHO revised 4th edition in 2017, and the upcoming WHO 5th edition and International Consensus Classification (ICC) for 2022.

Objectives: We present a case study of a 73-year-old female with a history of pancytopenia. The bone marrow core biopsy was suggestive of a myelodysplastic syndrome, unspecified (MDS-U). Chromosomal analysis of the bone marrow revealed an abnormal karyotype including gain of chromosomes 1, 4, 6, 8, 9, 19, and 20 in addition to loss of chromosomes 11, 13, 15, 16, 17, and 22. Also, additional material of unknown origin was found on 3q, 5p, 9p, 11p, 13p, 14p, and 15p; there were two copies of 19p, a deletion of 8q, and numerous unidentified rings and markers were present. This was characterized as: 75~77,XXX,+1,der(1;6)(p10;p10),add(3)(q27),+4,add(5)(p15.1),+6,+8,del(8)(q24.1),+add(9)(p24),-11,add (11) (p13),-13,add(13)(p10),add(14)(p11.2),-15,add(15)(p11.2), -16,-17,+19,add(19)(p13.3)x2,+20,-22, +0~4r,+4~10mar[cp11]/46,XX[8]. The cytogenetic analysis correlates with the concurrent FISH study which was positive for additional signals of EVI1(3q26.2), TAS2R1 (5p15.31), EGR1 (5q31.2), RELN (7q22), TES (7q31) RUNX1T1 (8q21.3), ABL1 (9q34), KMT2A (11q23), PML (15q24.1), CBFB (16q22), RARA (17q21), PTPRT (20q12), MYBL2 (20q13.12), RUNX1 (21q22.12) and BCR (22q11.2). Hyperdiploid karyotypes within the context of complex structural abnormalities are rare events usually associated with a poor prognosis in MDS.

Objectives: Objectives Disorders of sex development(DSD)can result in discordance between the chromosomal and anatomicand/orphenotypic sex of a patient. Reporting patients with uncommon karyotypes associated with DSD is important for clinical comparison of developmental outcomes, and management. Methods We describe three female patients with karyotypes resulting in DSD and the use of a combination of chromosomes and FISH techniques to identify potential causes. Results The first patient was mosaic for idic(Y) that was negative for SRY by FISH. The second patient had idic(Y) that was positive for SRY by FISH. The third patient had an unbalanced translocation between the X chromosome and chromosome 2 [der(2)(X;2)] and XY. These three patients illustrate three different genetic mechanisms underlying DSD. Conclusion Our findings expand the list of abnormal karyotypes that can be associated with DSD and highlight the importance of SRY and DAX1 in phenotypic and functional sexual development.

Objectives: The Janus Kinase 2 gene (JAK2) provides instructions for generating a protein that promotes the division and growth, or what is referred to as the proliferation, of cells. This generated protein relays signals in cells in order to promote cell growth, as well as help manage the count of white blood cells, red blood cells, and platelets that are generated within the bone marrow. Mutations and rearrangements of JAK2 are found in 3.5% of B-acute lymphoblastic leukemia (B-ALL) cases and in 18.9% of Down syndrome B-ALL patients, and are associated with a Ph-like ALL and a poor prognosis. However, there have been great challenges in understanding their role in this pathogenesis. In this review, we will discuss the most recent literature and trends associated with JAK2 mutations in patients with B-ALL.

Objectives: The Nobel Assembly at the Karolinska Institute awarded the 2022 Nobel Prize in Physiology or Medicine to Svante Pääbo (Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany). This award acknowledged his discoveries about the genomes of extinct hominins (Neandertal man and the Denisovans), the molecular genetic insights of human origin and evolutionary history, and the understanding of phylogenetic relationships between archaic hominins and modern humans. The scientific advances included detection of Neandertal and Denisovan DNA carried by modern humans due to past admixture events, which in turn stimulated active research about the functional and phenotypic significance of such archaic ancestry on non-disease and disease phenotypic features in modern populations. In addition, comparative genomic studies started to delineate the genes and genetic regulation mechanisms that distinguish modern-day humans from the archaic hominins and our immediate ancestors, the anatomically modern humans. These breakthroughs allowed a more thorough understanding of ancestral and modern human population genetics, and propelled the take-off of human paleogenomics as a new scientific discipline in its own right.

Objectives: A recent landmark study reported the value of next-generation sequencing (NGS) to uncover pathogenic abnormalities of clinical significance in patients with pediatric B-ALL enrolled in the UKALL2003 clinical trial (Schwab et al., 2023). NGS, as whole genome sequencing (WGS) or targeted NGS (t-NGS), was combined with previous data (cytogenetics, FISH and MLPA) from 351 pediatric patients with precursor B-ALL who lacked a defining genetic abnormality (B-other ALL). This integration of tests classified patients into 15 distinct subtypes, each one characterized by a specific abnormality. The most frequent subtypes were defined by abnormalities of PAX5, DUX4, ZNF384, an ABL class, and an ETV6::RUNX1-like with a gene expression profile similar to the typical ETV6::RUNX1 but without the specific abnormality. Quite conspicuously, WGS detected some classical abnormalities that remained undetected by standard cytogenomic methods. This application of NGS integrated into standard cytogenomic assays is a decisive advance in classifying patients with B-other ALL into distinct subtypes characterized by unique genomic changes. The addition of NGS improved the identification of pathogenic abnormalities and refined the classification as well as the risk stratification to determine clinical prognosis.

Objectives: Congenital neutropenia, defined by absolute neutrophil count (ANC) 2.5x109/L in infants, includes a variety of genotypic alterations that manifest with chronic immunodeficiency and, as a result, presents in infancy with recurrent infections. The gene that encodes neutrophil elastase, ELANE, has pathological variants yielding two distinct phenotypes: severe congenital neutropenia (SCN) and cyclic neutropenia (CyN). While SCN exhibits persistent pathologic ANC values, CyN exhibits pathologic ANC values in a patterned fashion which can recur in 21-day intervals. Here, we describe a patient with a novel heterozygous ELANE deletion (c.224+(4_19)del16) presenting with clinical features consistent with CyN and a response to first-line therapy of granulocyte colony- stimulating factor.