Classic and molecular cytogenetic findings in leukemia patients from the Western part of Romania.

Acute lymphoblastic leukemia (ALL) is the most common type of leukemia in childhood and rare in adults, while acute myeloid leukemia (AML) is less common in children and more common in older adults. The aim of the study was to present our experience for the diagnostic of leukemia by using the classic and molecular cytogenetic methods. The study was conducted between 2009 and 2019 within the Classic and Molecular Genetic Laboratory of the Oncohematology Department from the Louis Turcanu Emergency Hospital for Children, Timisoara, Romania. The study group included 337 children and adults, evaluated between 2009 and 2019. By using the conventional and molecular cytogenetic technique, the cytogenetic anomalies found were 35 numerical chromosomal abnormalities, 10 (9;22)(q34;q11) [four ALL, one AML, five chronic myeloid leukemia (CML)] translocations, nine (15;17)(q24;q21) translocations, three (14;14)(q11;q32) translocations, two (4;11)(q21;q23) translocations, one (1;14)(p32;q11) translocation, one (7;14)(qter;q11) translocation, one (8;21)(q22;q22) translocation, one (9;14)(p12;q32) translocation, seven rearrangements of the MLL gene and two rearrangements of the core-binding factor subunit beta∕myosin heavy chain 11 (CBFB∕MYH11) gene. The use of conventional and molecular cytogenetic analysis is one of the most important prognostic indicators in acute leukemia patients, allowing the identification of biologically distinct subtypes of disease and selection of appropriate treatment approaches.

Exploring the noncoding genome with chromosomal structural rearrangements.

Highlighting the Distinguished Speakers Symposium on "The Future of Human Genetics and Genomics," this collection of articles is based on presentations at the ASHG 2023 Annual Meeting in Washington, DC, in celebration of all our field has accomplished in the past 75 years, since the founding of ASHG in 1948.

Chromosomal abnormalities detected by chromosomal microarray analysis and pregnancy outcomes of 4211 fetuses with high-risk prenatal indications.

With the gradual liberalization of the three-child policy and the development of assisted reproductive technology in China, the number of women with high-risk pregnancies is gradually increasing. In this study, 4211 fetuses who underwent chromosomal microarray analysis (CMA) with high-risk prenatal indications were analysed. The results showed that the overall prenatal detection rate of CMA was 11.4% (480/4211), with detection rates of 5.82% (245/4211) for abnormal chromosome numbers and 5.58% (235/4211) for copy number variants. Additionally, the detection rates of clinically significant copy number variants were 3.78% (159/4211) and 1.8% (76/4211) for variants of uncertain significance. The detection rates of fetal chromosomal abnormalities were 6.42% (30/467) for pregnant women with advanced maternal age (AMA), 6.01% (50/832) for high-risk maternal serum screening (MSS) results, 39.09% (224/573) with abnormal non-invasive prenatal testing (NIPT) results, 9.21% (127/1379) with abnormal ultrasound results, and 5.1% (49/960) for other indications. Follow-up results were available for 4211 patients, including 3677 (3677/4211, 87.32%) whose infants were normal after birth, 462 (462/4211, 10.97%) who terminated their pregnancy, 51 (51/4211, 1.21%) whose infants were abnormal after birth, and 21 (21/4211, 0.50%) who refused follow-up. The results of this study demonstrate significant variation in the diagnostic rate of chromosomal microarray analysis across different indications, providing valuable guidance for clinicians to assess the applicability of CMA technology in prenatal diagnosis.

Prevalence of karyotype alterations in couples with recurrent pregnancy loss in a tertiary center in Brazil.

Objective: To assess the prevalence and type of chromosomal abnormalities in Brazilian couples with recurrent pregnancy loss (RPL) and compare the clinical characteristics of couples with and without chromosome abnormalities. Methods: We assessed the medical records of 127 couples with a history of two or more miscarriages, referred to a tertiary academic hospital in Belo Horizonte, Brazil, from January 2014 to May 2023. Karyotype was generated from peripheral blood lymphocyte cultures, and cytogenetic analysis was performed according to standard protocols by heat-denatured Giemsa (RHG) banding. Results: Abnormal karyotypes were detected in 10 couples (7.8%). The prevalence of chromosomal abnormalities was higher among females (6.3%) compared to males (2.0%), but this difference was not statistically significant (p=0.192). The mean number of miscarriages was. 3.3 ± 1.1 in couples with chromosome abnormalities and 3.1 ± 1.5 in couples without chromosome abnormalities (p=0.681). Numerical chromosomal anomalies (6 cases) were more frequent than structural anomalies. Four women presented low-grade Turner mosaicism. No differences were found between couples with and without karyotype alterations, except for maternal age, which was higher in the group with chromosome alterations. Conclusion: The prevalence of parental chromosomal alterations in our study was higher than in most series described in the literature and was associated with increased maternal age. These findings suggest that karyotyping should be part of the investigation for Brazilian couples with RPL, as identifying the genetic etiology may have implications for subsequent pregnancies.

Enhancement of the Clastogenic Effects of Topotecan In Vivo by Tyrosyl-DNA Phosphodiesterase 1 Inhibitors.

Topotecan administered intraperitoneally at single doses of 0.25, 0.5, and 1 mg/kg induced chromosomal aberrations in bone marrow cells of F1(CBA×C57BL/6) hybrid mice in a dose-dependent manner. A tyrosyl-DNA phosphodiesterase 1 (TDP1) inhibitor, an usnic acid derivative OL9-116 was inactive in a dose range of 20-240 mg/kg, but enhanced the cytogenetic effect of topotecan (0.25 mg/kg) at a dose of 40 mg/kg (per os). The TDP1 inhibitor, a coumarin derivative TX-2552 (at doses of 20, 40, 80, and 160 mg/kg per os), increased the level of aberrant metaphases induced by topotecan (0.25 mg/kg) by 2.1-2.6 times, but was inactive at a dose of 10 mg/kg. The results indicate that TDP1 inhibitors enhance the clastogenic activity of topotecan in mouse bone marrow cells in vivo and are characterized by different dose profiles of the co-mutagenic effects.

G0-PCC-FISH derived multi-parametric biodosimetry methodology for accidental high dose and partial body exposures.

High dose radiation exposures are rare. However, medical management of such incidents is crucial due to mortality and tissue injury risks. Rapid radiation biodosimetry of high dose accidental exposures is highly challenging, considering that they usually involve non uniform fields leading to partial body exposures. The gold standard, dicentric assay and other conventional methods have limited application in such scenarios. As an alternative, we propose Premature Chromosome Condensation combined with Fluorescent In-situ Hybridization (G0-PCC-FISH) as a promising tool for partial body exposure biodosimetry. In the present study, partial body exposures were simulated ex-vivo by mixing of uniformly exposed blood with unexposed blood in varying proportions. After G0-PCC-FISH, Dolphin's approach with background correction was used to provide partial body exposure dose estimates and these were compared with those obtained from conventional dicentric assay and G0-PCC-Fragment assay (conventional G0-PCC). Dispersion analysis of aberrations from partial body exposures was carried out and compared with that of whole-body exposures. The latter was inferred from a multi-donor, wide dose range calibration curve, a-priori established for whole-body exposures. With the dispersion analysis, novel multi-parametric methodology for discerning the partial body exposure from whole body exposure and accurate dose estimation has been formulated and elucidated with the help of an example. Dose and proportion dependent reduction in sensitivity and dose estimation accuracy was observed for Dicentric assay, but not in the two PCC methods. G0-PCC-FISH was found to be most accurate for the dose estimation. G0-PCC-FISH has potential to overcome the shortcomings of current available methods and can provide rapid, accurate dose estimation of partial body and high dose accidental exposures. Biological dose estimation can be useful to predict progression of disease manifestation and can help in pre-planning of appropriate & timely medical intervention.

Prediction of chromosomal abnormalities in the screening of the first trimester of pregnancy using machine learning methods: a study protocol.

BACKGROUND: For women in the first trimester, amniocentesis or chorionic villus sampling is recommended for screening. Machine learning has shown increased accuracy over time and finds numerous applications in enhancing decision-making, patient care, and service quality in nursing and midwifery. This study aims to develop an optimal learning model utilizing machine learning techniques, particularly neural networks, to predict chromosomal abnormalities and evaluate their predictive efficacy. METHODS/ DESIGN: This cross-sectional study will be conducted in midwifery clinics in Mashhad, Iran in 2024. The data will be collected from 350 pregnant women in the high-risk group who underwent screening tests in the first trimester (between 11-14 weeks) of pregnancy. Information collected includes maternal age, BMI, smoking habits, history of trisomy 21 and other chromosomal disorders, CRL and NT levels, PAPP-A and B-HCG levels, presence of insulin-dependent diabetes, and whether the pregnancy resulted from IVF. The study follows up with the women during their clinic visits and tracks the results of amniocentesis. Sampling is based on Convenience Sampling, and data is gathered using a checklist of characteristics and screening/amniocentesis results. After preprocessing, feature extraction is conducted to identify and predict relevant features. The model is trained and evaluated using K-fold cross-validation. DISCUSSION: There is a growing interest in utilizing artificial intelligence methods, like machine learning and deep learning, in nursing and midwifery. This underscores the critical necessity for nurses and midwives to be well-versed in artificial intelligence methods and their healthcare applications. It can be beneficial to develop a machine learning model, specifically focusing on neural networks, for predicting chromosomal abnormalities. ETHICAL CODE: IR.MUMS.NURSE.REC. 1402.134.

Approximately 3% of newborns are affected by congenital abnormalities and genetic diseases, leading to disability and death. Among live births, around 3000 cases of Down syndrome (trisomy 21) can be expected based on the country's birth rate. Pregnant women carrying fetuses with Down syndrome face an increased risk of pregnancy complications. Artificial intelligence methods, such as machine learning and deep learning, are being used in nursing and midwifery to improve decision-making, patient care, and research. Nurses need to actively participate in the development and implementation of AI-based decision support systems. Additionally, nurses and midwives should play a key role in evaluating the effectiveness of artificial intelligence-based technologies in professional practice.

Werner helicase interacting protein 1 contributes to G-quadruplex processing in human cells.

Genome replication is frequently impeded by highly stable DNA secondary structures, including G-quadruplex (G4) DNA, that can hinder the progression of the replication fork. Human WRNIP1 (Werner helicase Interacting Protein 1) associates with various components of the replication machinery and plays a crucial role in genome maintenance processes. However, its detailed function is still not fully understood. Here we show that human WRNIP1 interacts with G4 structures and provide evidence for its contribution to G4 processing. The absence of WRNIP1 results in elevated levels of G4 structures, DNA damage and chromosome aberrations following treatment with PhenDC3, a G4-stabilizing ligand. Additionally, we establish a functional and physical relationship between WRNIP1 and the PIF1 helicase in G4 processing. In summary, our results suggest that WRNIP1 aids genome replication and maintenance by regulating G4 processing and this activity relies on Pif1 DNA helicase.

Prenatal ultrasound diagnosis and quality control of fetal nuchal translucency. / èƒŽå„¿é¢ˆé¡¹é€æ˜Žå±‚äº§å‰è¶ å£°è¯Šæ–­åŠè´¨é‡æŽ§åˆ¶.

OBJECTIVES: In clinical ultrasound examinations, it is challenging to perform quality control on the images of each fetal nuchal translucency (NT) and crown-rump length (CRL). However, small measurement differences can increase the probability of false-positive or false-negative diagnosis. Therefore, it is necessary to establish a quality control system for fetal NT examination. This study aims to control the quality of fetal NT and CRL measurements, evaluate the accuracy of ultrasound physicians in early pregnancy NT measurements, and analyze the impact of increased fetal structure screening on the detection rate of chromosomal abnormalities. METHODS: Data were collected from cases before and after 12 months of NT examination quality control, with 2 214 before quality control and 2 538 cases after quality control. Three quality control data metrics were analyzed: NT multiple of median (NT-MoM), standard deviation (SD) of log10MoM [(SD) log10MoM], and the slope of NT on CRL (SNC). The performance of NT measurements was monitored through the individual CRL NT-MoM within the 0.9-1.1 MoM range of the normal median curve, while grouped based on different years of experience (<3 years, 3-6 years, >6 years), and NT-MoM values among these groups were compared. Data on NT thickening, structural anomalies, and chromosomal abnormalities were retrospectively analyzed during the quality control period. RESULTS: According to the curve equation of the American NTQR project group, the NT-MoM value before quality control was 0.921 7 MoM, the (SD) log10MoM value was 0.091 92, and the SNC value was 12.20%. After quality control, the NT-MoM value was 0.948 3 MoM, the (SD) log10MoM value was 0.094 81, and the SNC value was 11.43%. The comparison of NT-MoM values before and after quality control showed a statistically significant difference (P<0.000 1). The comparison of NT-MoM values measured by ultrasound physicians with different years of experience before and after quality control also showed statistically significant differences (P<0.000 1). The NT-MoM values for the 3-6 years and >6 years groups were higher after quality control (P<0.05), while the <3 years group showed no significant difference before and after quality control (P>0.05). After quality control, cases of NT thickening without significant structural abnormalities accounted for 19.05%, NT thickening with structural abnormalities accounted for 47.62%, and NT normal with structural abnormalities accounted for 33.33%. There were 36 cases of fetal heart abnormalities, accounting for 20.34% of the total abnormality rate, with a positive rate of 36% in chromosome tests. CONCLUSIONS: After quality control, ultrasound physicians measure NT more accurately, but differences among measurements remain. Measurements by experienced ultrasound physicians are closer to expected values, usually lower than expected. Monitoring fetal NT and CRL measurements helps improve measurement accuracy. Increasing structural screening during NT examinations, especially for the fetal heart, enhances the detection rate of chromosomal abnormalities.

Prenatal diagnosis and genetic analysis of small supernumerary marker chromosomes in the eastern chinese han population: A retrospective study of 36 cases.

BACKGROUND: Small supernumerary marker chromosomes (sSMCs) are additional chromosomes with unclear structures and origins, and their correlations with clinical fetal phenotypes remain incompletely understood, which reduces the accuracy of genetic counseling. METHODS: We conducted a retrospective analysis of a cohort of 36 cases of sSMCs diagnosed in our center. We performed G-banding and chromosomal microarray analysis (CMA). The resulting karyotypes were compared with case reports in the literature and various databases including OMIM, DECIPHER, ClinVar, ClinGen, ISCA, DGV, and PubMed. RESULTS: Karyotype analysis data revealed that 19 out of 36 fetuses were mosaic. Copy number variants (CNVs) analysis results showed that 27 out of 36 fetuses harbored pathogenic/likely pathogenic variants. Among these 27 cases, 11 fetuses carried sex chromosome-related CNVs, including 4 female cases exhibiting Turner syndrome phenotypes and 7 cases showing Y chromosome deletions. In the remaining 16 fetuses with autosomal CNVs, 9 fetuses carried variants associated with Cat eye syndrome, Emanuel syndrome, Tetrasomy 18p, and 15q11-q13 duplication syndrome. Among these, 22 fetuses were terminated, and the remaining 5 fetuses were delivered and developed normally. Additionally, we identified a few variants with unclear pathogenicity. CONCLUSION: Cytogenetic analysis is essential for identifying the pathogenicity of sSMCs and increasing the accuracy of genetic counseling.

Sleep EEG signatures in mouse models of 15q11.2-13.1 duplication (Dup15q) syndrome.

BACKGROUND: Sleep disturbances are a prevalent and complex comorbidity in neurodevelopmental disorders (NDDs). Dup15q syndrome (duplications of 15q11.2-13.1) is a genetic disorder highly penetrant for NDDs such as autism and intellectual disability and it is frequently accompanied by significant disruptions in sleep patterns. The 15q critical region harbors genes crucial for brain development, notably UBE3A and a cluster of gamma-aminobutyric acid type A receptor (GABAAR) genes. We previously described an electrophysiological biomarker of the syndrome, marked by heightened beta oscillations (12-30 Hz) in individuals with Dup15q syndrome, akin to electroencephalogram (EEG) alterations induced by allosteric modulation of GABAARs. Those with Dup15q syndrome exhibited increased beta oscillations during the awake resting state and during sleep, and they showed profoundly abnormal NREM sleep. This study aims to assess the translational validity of these EEG signatures and to delve into their neurobiological underpinnings by quantifying sleep physiology in chromosome-engineered mice with maternal (matDp/ + mice) or paternal (patDp/ + mice) inheritance of the full 15q11.2-13.1-equivalent duplication, and mice with duplication of just the UBE3A gene (Ube3a overexpression mice; Ube3a OE mice) and comparing the sleep metrics with their respective wildtype (WT) littermate controls. METHODS: We collected 48-h EEG/EMG recordings from 35 (23 male, 12 female) 12-24-week-old matDp/ + , patDp/ + , Ube3a OE mice, and their WT littermate controls. We quantified baseline sleep, sleep fragmentation, spectral power dynamics during sleep states, and recovery following sleep deprivation. Within each group, distinctions between Dup15q mutant mice and WT littermate controls were evaluated using analysis of variance (ANOVA) and student's t-test. The impact of genotype and time was discerned through repeated measures ANOVA, and significance was established at p < 0.05. RESULTS: Our study revealed that across brain states, matDp/ + mice mirrored the elevated beta oscillation phenotype observed in clinical EEGs from individuals with Dup15q syndrome. Time to sleep onset after light onset was significantly reduced in matDp/ + and Ube3a OE mice. However, NREM sleep between Dup15q mutant and WT littermate mice remained unaltered, suggesting a divergence from the clinical presentation in humans. Additionally, while increased beta oscillations persisted in matDp/ + mice after 6-h of sleep deprivation, recovery NREM sleep remained unaltered in all groups, thus suggesting that these mice exhibit resilience in the fundamental processes governing sleep-wake regulation. CONCLUSIONS: Quantification of mechanistic and translatable EEG biomarkers is essential for advancing our understanding of NDDs and their underlying pathophysiology. Our study of sleep physiology in the Dup15q mice underscores that the beta EEG biomarker has strong translational validity, thus opening the door for pre-clinical studies of putative drug targets, using the biomarker as a translational measure of drug-target engagement. The unaltered NREM sleep may be due to inherent differences in neurobiology between mice and humans. These nuanced distinctions highlight the complexity of sleep disruptions in Dup15q syndrome and emphasize the need for a comprehensive understanding that encompasses both shared and distinct features between murine models and clinical populations.

Multi-step control of homologous recombination via Mec1/ATR suppresses chromosomal rearrangements.

The Mec1/ATR kinase is crucial for genome stability, yet the mechanism by which it prevents gross chromosomal rearrangements (GCRs) remains unknown. Here we find that in cells with deficient Mec1 signaling, GCRs accumulate due to the deregulation of multiple steps in homologous recombination (HR). Mec1 primarily suppresses GCRs through its role in activating the canonical checkpoint kinase Rad53, which ensures the proper control of DNA end resection. Upon loss of Rad53 signaling and resection control, Mec1 becomes hyperactivated and triggers a salvage pathway in which the Sgs1 helicase is recruited to sites of DNA lesions via the 911-Dpb11 scaffolds and phosphorylated by Mec1 to favor heteroduplex rejection and limit HR-driven GCR accumulation. Fusing an ssDNA recognition domain to Sgs1 bypasses the requirement of Mec1 signaling for GCR suppression and nearly eliminates D-loop formation, thus preventing non-allelic recombination events. We propose that Mec1 regulates multiple steps of HR to prevent GCRs while ensuring balanced HR usage when needed for promoting tolerance to replication stress.

Human Genetics of Ventricular Septal Defect.

Ventricular septal defects (VSDs) are recognized as one of the commonest congenital heart diseases (CHD), accounting for up to 40% of all cardiac malformations, and occur as isolated CHDs as well as together with other cardiac and extracardiac congenital malformations in individual patients and families. The genetic etiology of VSD is complex and extraordinarily heterogeneous. Chromosomal abnormalities such as aneuploidy and structural variations as well as rare point mutations in various genes have been reported to be associated with this cardiac defect. This includes both well-defined syndromes with known genetic cause (e.g., DiGeorge syndrome and Holt-Oram syndrome) and so far undefined syndromic forms characterized by unspecific symptoms. Mutations in genes encoding cardiac transcription factors (e.g., NKX2-5 and GATA4) and signaling molecules (e.g., CFC1) have been most frequently found in VSD cases. Moreover, new high-resolution methods such as comparative genomic hybridization enabled the discovery of a high number of different copy number variations, leading to gain or loss of chromosomal regions often containing multiple genes, in patients with VSD. In this chapter, we will describe the broad genetic heterogeneity observed in VSD patients considering recent advances in this field.

Human Genetics of Tricuspid Atresia and Univentricular Heart.

Tricuspid atresia (TA) is a rare congenital heart condition that presents with a complete absence of the right atrioventricular valve. Because of the rarity of familial and/or isolated cases of TA, little is known about the potential genetic abnormalities contributing to this condition. Potential responsible chromosomal abnormalities were identified in exploratory studies and include deletions in 22q11, 4q31, 8p23, and 3p as well as trisomies 13 and 18. In parallel, potential culprit genes include the ZFPM2, HEY2, NFATC1, NKX2-5, MYH6, and KLF13 genes. The aim of this chapter is to expose the genetic components that are potentially involved in the pathogenesis of TA in humans. The large variability in phenotypes and genotypes among cases of TA suggests a genetic network that involves many components yet to be unraveled.

[Effect of TP53 Allelic State on Clinical Performance and Prognosis of Patients with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the clinical significance of TP53 allelic state in patients with myelodysplastic syndromes (MDS). METHODS: The clinical data of 858 MDS patients who underwent second-generation sequencing (NGS) testing in the First Affiliated Hospital of Soochow University from January 2019 to December 2021 were retrospectively analyzed. RESULTS: The median age of the patients was 52 years old, and median follow-up time was 23.8 (0.4-109.6) months. Four hundred and one patients (46.7%) had at least one chromosomal abnormality, including 106 complex karyotypes and 78 monosomal karyotypes. A total of 103 cases of TP53 mutations were identified, with a mutation rate of 12%. Compared with TP53 wild-type, various types of chromosomal abnormalities were significantly more common in patients with TP53 mutations (all P < 0.001). Patients with TP53 mutations had lower hemoglobin levels, lower platelet counts and higher percentage of bone marrow primitive cell compared with TP53 wild type (all P < 0.05), and significantly shorter overall survival (OS). Among 97 evaluable patients, 33 cases (34%) were mono-allelic TP53 mutation, while 64 cases were bi-allelic TP53 mutation. Patients in bi-allelic TP53 mutation subgroup had a higher proportion of chromosomal abnormalities and a lower number of co-mutations compared with mono-allelic TP53 mutation. The median OS was 33.6 months in patients with mono-allelic state and only 11.4 months in patients with bi-allelic state (HR=2.138, 95%CI : 1.053-4.343, P >0.05). Median OS was not reached in TP53 wild-type patients, and there was a significant difference in OS among TP53 wild-type, mono-allelic and bi-allelic TP53 mutation patients (P < 0.001). Multivariable Cox regression analysis showed that bi-allelic TP53 was an independent predictor of poor outcomes (HR=2.808, 95%CI : 1.487-5.003, P =0.001), while mono-allelic TP53 mutation and wild-type TP53 were not. CONCLUSION: Patients with TP53 mutations have a poor prognosis, and bi-allelic TP53 mutations have a worse prognosis compared with mono-allelic TP53 mutations and independently affect the prognosis of MDS patients.

High hyperdiploid karyotype with ≥ 49 chromosomes represents a heterogeneous subgroup of acute myeloid leukemia with differential TP53 mutation status and prognosis: a single-center study from China.

High hyperdiploid karyotype with ≥ 49 chromosomes (which will be referred to as HHK) is rare in acute myeloid leukemia (AML). The European leukemia network (ELN) excluded those harboring only numerical changes (with ≥ 3 chromosome gains) from CK and listed them in the intermediate risk group, while the UK National Cancer Research Institute Adult Leukaemia Working Group classification defined ≥ 4 unrelated chromosome abnormalities as the cutoff for a poorer prognosis. Controversies occurred among studies on the clinical outcome of HHK AML, and their molecular characteristics remained unstudied. We identified 1.31% (133/10,131) HHK cases within our center, among which 48 cases only had numerical changes (NUM), 42 had ELN defined adverse abnormalities (ADV) and 43 had other structural abnormalities (STR). Our study demonstrated that: (1) No statistical significance for overall survival (OS) was observed among three cytogenetic subgroups (NUM, STR and ADV) and HHK AML should be assigned to the adverse cytogenetic risk group. (2) The OS was significantly worse in HHK AML with ≥ 51 chromosomes compared with those with 49-50 chromosomes. (3) The clinical characteristics were similar between NUM and STR group compared to ADV group. The former two groups had higher white blood cell counts and blasts, lower platelet counts, and mutations associated with signaling, while the ADV group exhibited older age, higher chromosome counts, higher percentage of myelodysplastic syndrome (MDS) history, and a dominant TP53 mutation.

Cancer cytogenetics in a genomics world: Wedding the old with the new.

Since the discovery of the Philadelphia chromosome in 1960, cytogenetic studies have been instrumental in detecting chromosomal abnormalities that can inform cancer diagnosis, treatment, and risk assessment efforts. The initial expansion of cancer cytogenetics was with fluorescence in situ hybridization (FISH) to assess submicroscopic alterations in dividing or non-dividing cells and has grown into the incorporation of chromosomal microarrays (CMA), and next generation sequencing (NGS). These molecular technologies add additional dimensions to the genomic assessment of cancers by uncovering cytogenetically invisible molecular markers. Rapid technological and bioinformatic advances in NGS are so promising that the idea of performing whole genome sequencing as part of routine patient care may soon become economically and logistically feasible. However, for now cytogenetic studies continue to play a major role in the diagnostic testing and subsequent assessments in leukemia with other genomic studies serving as complementary testing options for detection of actionable genomic abnormalities. In this review, we discuss the role of conventional cytogenetics (karyotyping, chromosome analysis) and FISH studies in hematological malignancies, highlighting the continued clinical utility of these techniques, the subtleties and complexities that are relevant to treating physicians and the unique strengths of cytogenetics that cannot yet be paralleled by the current high-throughput molecular technologies. Additionally, we describe how CMA, optical genome mapping (OGM), and NGS detect abnormalities that were beyond the capacity of cytogenetic studies and how an integrated approach (broad molecular testing) can contribute to the detection of actionable targets and variants in malignancies. Finally, we discuss advances in the field of genomic testing that are bridging the advantages of individual (single) cell based cytogenetic testing and broad genomic testing.

A Paradoxical Role for Somatic Chromosomal Mosaicism and Chromosome Instability in Cancer: Theoretical and Technological Aspects.

Somatic chromosomal mosaicism, chromosome instability, and cancer are intimately linked together. Addressing the role of somatic genome variations (encompassing chromosomal mosaicism and instability) in cancer yields paradoxical results. Firstly, somatic mosaicism for specific chromosomal rearrangement causes cancer per se. Secondly, chromosomal mosaicism and instability are associated with a variety of diseases (chromosomal disorders demonstrating less severe phenotypes, complex diseases), which exhibit cancer predisposition. Chromosome instability syndromes may be considered the best examples of these diseases. Thirdly, chromosomal mosaicism and instability are able to result not only in cancerous diseases but also in non-cancerous disorders (brain diseases, autoimmune diseases, etc.). Currently, the molecular basis for these three outcomes of somatic chromosomal mosaicism and chromosome instability remains incompletely understood. Here, we address possible mechanisms for the aforementioned scenarios using a system analysis model. A number of theoretical models based on studies dedicated to chromosomal mosaicism and chromosome instability seem to be valuable for disentangling and understanding molecular pathways to cancer-causing genome chaos. In addition, technological aspects of uncovering causes and consequences of somatic chromosomal mosaicism and chromosome instability are discussed. In total, molecular cytogenetics, cytogenomics, and system analysis are likely to form a powerful technological alliance for successful research against cancer.

The Importance of Monitoring Non-clonal Chromosome Aberrations (NCCAs) in Cancer Research.

Cytogenetic analysis has traditionally focused on the clonal chromosome aberrations, or CCAs, and considered the large number of diverse non-clonal chromosome aberrations, or NCCAs, as insignificant noise. Our decade-long karyotype evolutionary studies have unexpectedly demonstrated otherwise. Not only the baseline of NCCAs is associated with fuzzy inheritance, but the frequencies of NCCAs can also be used to reliably measure genome or chromosome instability (CIN). According to the Genome Architecture Theory, CIN is the common driver of cancer evolution that can unify diverse molecular mechanisms, and genome chaos, including chromothripsis, chromoanagenesis, and polypoidal giant nuclear and micronuclear clusters, and various sizes of chromosome fragmentations, including extrachromosomal DNA, represent some extreme forms of NCCAs that play a key role in the macroevolutionary transition. In this chapter, the rationale, definition, brief history, and current status of NCCA research in cancer are discussed in the context of two-phased cancer evolution and karyotype-coded system information. Finally, after briefly describing various types of NCCAs, we call for more research on NCCAs in future cytogenetics.