Unbalanced Chromosomal Abnormalities Research Articles

Recurrent MiscarriageGreen-top Guideline No. 17.

In this guideline, recurrent miscarriage has been defined as three or more first trimester miscarriages. However, clinicians are encouraged to use their clinical discretion to recommend extensive evaluation after two first trimester miscarriages, if there is a suspicion that the miscarriages are of pathological and not of sporadic nature. Women with recurrent miscarriage should be offered testing for acquired thrombophilia, particularly for lupus anticoagulant and anticardiolipin antibodies, prior to pregnancy. [Grade C] Women with second trimester miscarriage may be offered testing for Factor V Leiden, prothrombin gene mutation and protein S deficiency, ideally within a research context. [Grade C] Inherited thrombophilias have a weak association with recurrent miscarriage. Routine testing for protein C, antithrombin deficiency and methylenetetrahydrofolate reductase mutation is not recommended. [Grade C] Cytogenetic analysis should be offered on pregnancy tissue of the third and subsequent miscarriage(s) and in any second trimester miscarriage. [Grade D] Parental peripheral blood karyotyping should be offered for couples in whom testing of pregnancy tissue reports an unbalanced structural chromosomal abnormality [Grade D] or there is unsuccessful or no pregnancy tissue available for testing. [GPP] Women with recurrent miscarriage should be offered assessment for congenital uterine anomalies, ideally with 3D ultrasound. [Grade B] Women with recurrent miscarriage should be offered thyroid function tests and assessment for thyroid peroxidase (TPO) antibodies. [Grade C] Women with recurrent miscarriage should not be routinely offered immunological screening (such as HLA, cytokine and natural killer cell tests), infection screening or sperm DNA testing outside a research context. [Grade C] Women with recurrent miscarriage should be advised to maintain a BMI between 19 and 25 kg/m2 , smoking cessation, limit alcohol consumption and limit caffeine to less than 200 mg/day. [Grade D] For women diagnosed with antiphospholipid syndrome, aspirin and heparin should be offered from a positive test until at least 34 weeks of gestation, following discussion of potential benefits versus risks. [Grade B] Aspirin and/or heparin should not be given to women with unexplained recurrent miscarriage. [Grade B] There are currently insufficient data to support the routine use of PGT-A for couples with unexplained recurrent miscarriage, while the treatment may carry a significant cost and potential risk. [Grade C] Resection of a uterine septum should be considered for women with recurrent first or second trimester miscarriage, ideally within an appropriate audit or research context. [Grade C] Thyroxine supplementation is not routinely recommended for euthyroid women with TPO who have a history of miscarriage. [Grade A] Progestogen supplementation should be considered in women with recurrent miscarriage who present with bleeding in early pregnancy (for example 400 mg micronised vaginal progesterone twice daily at the time of bleeding until 16 weeks of gestation). [Grade B] Women with unexplained recurrent miscarriage should be offered supportive care, ideally in the setting of a dedicated recurrent miscarriage clinic. [Grade C].

Retrospective Analysis of Meiotic Segregation Pattern and Reproductive Outcomes in Blastocysts from Robertsonian Preimplantation Genetic Testing Cycles.

In this retrospective study, 120 heterozygous Robertsonian translocation carriers undergoing preimplantation genetic testing (PGT) were included, between January 2018 and September 2021. Meiotic segregation patterns of 462 embryos from 51 female carriers and 69 male carriers were analyzed according to chromosome type, carrier's sex, and female age. The proportion of alternate embryos in female carriers was slightly lower than that in male carriers [P < 0.001, odds ratio (OR) = 0.512]. By contrast, no difference was observed among Rob (13;14), Rob (14;21), and rare RobT groups. Stratification analysis of female carriers' age doses showed no significant increase in unbalanced chromosomal abnormalities. Reproductive outcomes of 144 frozen-thawed cycles were analyzed. All 144 blastocysts were transferred, and there were no significant differences in the clinical pregnancy rates per transfer (CPR), miscarriage rates (MR), live birth rates per transfer (LBR), and cumulative live birth rates between female carriers and male carriers. In addition, couples in Rob (13;14), Rob (14;21), and rare RobTs groups had comparative clinical pregnancy rates per transfer (CPR), miscarriage rates (MR), live birth rates per transfer (LBR), and cumulative live birth rates. Our study demonstrated that the meiotic segregation pattern of Robertsonian translocations carriers is associated with the carrier's sex, but not the carrier's translocation type and female age. In addition, the sex of translocation carriers only affects the meiotic segregation pattern but does not influence the subsequent viability of normal embryos and live birth.

Genetic and semen examination of patients with 46,XX testicular disorder of sex development

Background. 46,XX male syndrome (XX sex reversal) or 46,ХХ testicular disorder of sex development (DSD) – a genetic disorder that characterized by primary hypogonadism and male infertility because of severe spermatogenesis defects. 46,XX testicular DSD is resulted from unbalanced microstructural sex chromosome abnormalities, mostly X-Y translocations involving SRY gene. Genetic heterogeneity and phenotypic variability, particularly the effect of the genotype on semen parameters in XX sex reversed patients are not sufficiently studied.Aim. Genetic and semen examination in patients with 46,ХХ testicular DSD.Materials and methods. 32 patients with 46,XX testicular DSD and 2 men with mosaicism 46,XX/46,XY were examined. Cytogenetics, molecular genetics and spermatology examination (standard semen analysis and quantitative karyological analysis of immature germ cells) were performed.Results. The presence of the SRY gene was detected in 23 (82.1 %) of 28 patients who underwent a molecular genetic study, and 5 patientswere SRY-negative. Azoospermia and severe oligozoospermiawere diagnosed in 24 (75 %) and 8 (25 %) patients, respectively. Quantitative karyological analysis of immature germ cells allowed to reveal cryptozoospermia in 3 patients with initially diagnosed azoospermia (according to a standard semen analysis). Severe oligozoospermia and cryptozoospermia were mentioned both in some of SRY-positive and SRY-negative patients.Conclusion. 46,XX testicular DSD is characterized by severe degree of spermatogenesis defects (azoospermia and extremely severe oligozoospermia). Small number of germ cells detected in ejaculate in some patients with 46,XX testicular DSD, including SRY-negative individuals, indicates partial preservation ofspermatogenesisin the absence of Y chromosome genes.

Analysis of a fetus with unbalanced translocation derived from a balanced t(6;14) maternal translocation

To explore the genetic characteristics of a fetus with a high risk by maternal serum screening during the second trimester. Genetic counseling was provided to the pregnant woman on March 22, 2020 at Henan Provincial People's Hospital. G-banded chromosomal karyotyping and array comparative genomic hybridization (aCGH) were carried out on the amniotic fluid sample and peripheral blood samples from the couple. The fetus and the pregnant woman were respectively found to have a 46,XX,der(6)t(6;14)(q27;q31.2) and 46,XX,t(6;14)(q27;q31.2) karyotype, whilst the husband was found to have a normal karyotype. aCGH analysis has identified a 6.64 Mb deletion at 6q26q27 and a 19.98 Mb duplication at 14q31.3q32.33 in the fetus, both of which were predicted to be pathogenic copy number variations. No copy number variation was found in the couple. The unbalanced chromosome abnormalities in the fetus have probably derived from the balanced translocation carried by the pregnant woman. aCGH can help to determine the types of fetal chromosome abnormalities and site of chromosomal breakage, which may facilitate the prediction of fetal outcome and choice for subsequent pregnancies.

The presence of a chromosomal abnormality in cytopenia without dysplasia identifies a category of high-risk clonal cytopenia of unknown significance.

Myelodysplastic syndromes (MDS) are hematological malignancies classically defined by the presence of cytopenia(s) and dysmorphic myeloid cells. It is now known that MDS can be preceded by a pre-malignant condition called clonal cytopenia of unknown significance (CCUS), which associates a clonality marker with cytopenia in the absence of criteria of dysplasia. However, to date, it is not clear whether chromosomal abnormalities should be considered in the definition of CCUS or if they carry a prognostic impact in CCUS patients. In this study, we analyzed the clinico-biological features and outcomes of 34 patients who presented with one or more cytopenias, an absence of significant dysplasia, and a presence of a chromosomal abnormality (CA). We named this entity chromosomal abnormality with cytopenia of undetermined significance (CACtUS). We show that these patients are slightly older than MDS patients and that they more frequently presented with normocytic anemia. Most CACtUS patients exhibited only one unbalanced CA. The number and type of mutations were comparable between CACtUS patients and MDS patients. Regardless of the cytogenetic abnormality, the clinicobiological characteristics, overall survival, and risk of progression to high-risk (HR) MDS were similar between CACtUS patients and low-risk MDS patients. Thus, we suggest that CACtUS patients can be considered as HR-CCUS and should receive the follow-up regimen recommended for MDS patients.

Prenatal diagnosis and genetic counseling of a paternally inherited microduplication 18q11.1 to 18q11.2 in a chinese family

BackgroundCopy number variants are a substantial source of pathogenic or normal genome variations. Chromosomal imbalances of several megabasepair are normally harmful for the affected person. Still, rarely reported are so-called “unbalanced chromosome abnormalities” (UBCAs), which are either losses or gains or equally large genomic regions, but the carrier is only minimally clinically affected even no clinically affected. The knowledge of such UBCAs is imperative also in noninvasive prenatal testing (NIPT) or chromosomal microarray analysis.Case presentationA paternally inherited dup(18)(q11.1q11.2) was identified in a over two generations in a Chinese family. The affected region encompasses 25 genes, among which GATA6 is expressed in fetal endothelial cells and mesodermal cells. GATA6 duplications and /or mutations have been seen in cases with congenital heart disease but also non-affected individuals, suggesting incomplete penetrance and variable expressivity.ConclusionsDuplications in the region of chromosome 18q11 have been rare reported previously in clinically healthy persons. Here a further family with an UBCA in 18q11 is added to the literature, suggesting a careful genetic counselling in prenatal diagnosis.

Prenatal diagnosis and genetic counseling of an inherited unbalanced chromosome abnormalities in a Chinese family

BackgroundUnbalanced chromosome abnormalities (UBCA) are either gains or losses or large genomic regions, but the affected person is not or only minimally clinically affected. Copy number variants (CNVs) are an important source of normal and pathogenic genome variations. CNVs and UBCA identified in prenatal cases need careful considerations and correct interpretation if those are harmless or harmful variants from the norm.Case presentationA 25-year-old, gravida 1, para 0, woman underwent amniocentesis at 18 weeks of gestation because the noninvasive prenatal testing (NIPT) results revealed a 6.8 Mb duplication from 2q11.1 to 2q11.2. Chromosomal microarray analysis (CMA) was performed on uncultured amniocytes. GTG-banding karyotype analysis on cultured amniocytes was performed.ResultsChromosomal GTG-banding of the cultured amniocytes revealed a karyotype of 46,XX. CMA detected a 6.8-Mb chromosomal duplication in the region of 2q11.1q11.2 (arr[GRCh37] 2q11.1q11.2(95,327,873_102,088,148)x3).ConclusionChromosomal microdeletions and microduplications are difficult to detect by conventional cytogenetics, combination of prenatal ultrasound, karyotype analysis, NIPT, CMA and genetic counseling is helpful for the prenatal diagnosis of UBCA and chromosomal microdeletions/microduplications.

Molecular cytogenetics in acute myeloid leukemia in adult patients: practical implications.

Throughout the last 50 years, cytogenetic analyses of pretreatment bone marrow and / or blood samples from patients diagnosed with acute myeloid leukemia (AML) revealed a large number of recurring chromosome aberrations, both structural and numerical. Using standard banding methods and, more recently, molecular cytogenetic techniques, such as fluorescence in situ hybridization, spectral karyotyping, multiplex fluorescence in situ hybridization and comparative genomic hybridization, cytogenetic investigations detect acquired abnormalities that, together with submicroscopic gene mutations and changes in gene expression, strongly influence the clinical features and prognosis of patients with AML. Selected reciprocal translocations and inversions and their molecular counterparts, as well as a number of unbalanced chromosome abnormalities are used, together with bone marrow morphology, immunophenotype, and clinical characteristics, to define separate AML entities in the World Health Organization Classification of Haematolymphoid Tumours. Moreover, cytogenetic findings (and specific gene mutations) are being used in geneticrisk classifications, such as the 2022 European LeukemiaNet classification. Such classifications divide patients into broad prognostic categories: favorable, intermediate, and adverse, which are useful in the management of adults with AML. In this article, I review the present data on recurrent chromosome rearrangements in AML and on correlations between cytogenetic findings and clinical features and treatment outcomes of adult patients diagnosed with AML.

Prenatal diagnosis and genetic counseling of a 10p11.23q11.21 duplication associated with normal phenotype

BackgroundCopy number variants (CNVs) are an important source of normal and pathogenic genome variations. Unbalanced chromosome abnormalities (UBCA) are either gains or losses or large genomic regions, but the affected person is not or only minimally clinically affected. CNVs and UBCA identified in prenatal cases need careful considerations and correct interpretation if those are harmless or harmful variants from the norm.Case presentationA 24-year-old, gravida 1, para 0, woman underwent amniocentesis at 17 weeks of gestation because the noninvasive prenatal testing (NIPT) results revealed a 12.4 Mb duplication from 10p11.2 to 10q11.2. GTG-banding karyotype analysis was performed on cultured amniocytes. Chromosomal microarray analysis (CMA) on uncultured amniocytes was performed.ResultsChromosomal GTG-banding of the cultured amniocytes revealed a karyotype of 46,XX,dup(10)(p11.2q11.2). CMA detected a 12.5-Mb chromosomal duplication in the region of 10p11.23q11.21 (arr[GRCh37] 10p11.23q11.21(30,345,109_42,826,062) × 3).ConclusionThe present report enlarges the known UBCA region 10p11.22-10q11.22 to 10p11.23-10q11.22. Also it highlights that an integration of prenatal ultrasound, NIPT, karyotype analysis, CMA and genetic counseling is helpful for the prenatal diagnosis of chromosomal deletions/duplications.

GENType: all-in-one preimplantation genetic testing by pedigree haplotyping and copy number profiling suitable for third-party reproduction.

Is it possible to develop a comprehensive pipeline for all-in-one preimplantation genetic testing (PGT), also suitable for parents-only haplotyping and, for the first time, third-party reproduction? Optimized reduced representation sequencing (RRS) by GENType, along with a novel analysis platform (Hopla), enables cheap, accurate and comprehensive PGT of blastocysts, even without the inclusion of additional family members or both biological parents for genome-wide embryo haplotyping. Several haplotyping strategies have proven to be effective for comprehensive PGT. However, these methods often rely on microarray technology, whole-genome sequencing (WGS) or a combination of strategies, hindering sample throughput and cost-efficiency. Moreover, existing tools (including other RRS-based strategies) require both prospective biological parents for embryo haplotyping, impeding application in a third-party reproduction setting. This study included a total of 257 samples. Preliminary technical validation was performed on 81 samples handpicked from commercially available cell lines. Subsequently, a clinical validation was performed on a total of 72 trophectoderm biopsies from 24 blastocysts, tested for a monogenic disorder (PGT-M) (n = 15) and/or (sub)chromosomal aneuploidy (PGT-SR/PGT-A) (n = 9). Once validated, our pipeline was implemented in a diagnostic setting on 104 blastocysts for comprehensive PGT. Samples were whole-genome amplified (WGA) and processed by GENType. Quality metrics, genome-wide haplotypes, b-allele frequencies (BAFs) and copy number profiles were generated by Hopla. PGT-M results were deduced from relative haplotypes, while PGT-SR/PGT-A results were inferred from read-count analysis and BAF profiles. Parents-only haplotyping was assessed by excluding additional family members from analysis and using an independently diagnosed embryo as phasing reference. Suitability for third-party reproduction through single-parent haplotyping was evaluated by excluding one biological parent from analysis. Results were validated against reference PGT methods. Genome-wide haplotypes of single cells were highly accurate (mean > 99%) compared to bulk DNA. Unbalanced chromosomal abnormalities (>5 Mb) were detected by GENType. For both PGT-M as well as PGT-SR/PGT-A, our technology demonstrated 100% concordance with reference PGT methods for diverse WGA methods. Equally, for parents-only haplotyping and single-parent haplotyping (of autosomal dominant disorders and X-linked disorders), PGT-M results were fully concordant. Furthermore, the origin of trisomies in PGT-M embryos was correctly deciphered by Hopla. Intrinsic to linkage-analysis strategies, de novo single-nucleotide variants remain elusive. Moreover, parents-only haplotyping is not a stand-alone approach and requires prior diagnosis of at least one reference embryo by an independent technology (i.e. direct mutation analysis) for haplotype phasing. Using a haplotyping approach, the presence of a homologous recombination site across the chromosome is biologically required to distinguish meiotic II errors from mitotic errors during trisomy origin investigation. We offer a generic, fully automatable and accurate pipeline for PGT-M, PGT-A and PGT-SR as well as trisomy origin investigation without the need for personalized assays, microarray technology or WGS. The unique ability to perform single-parent assisted haplotyping of embryos paves the way for cost-effective PGT in a third-party reproduction setting. L.D.W. is supported by the Research Foundation Flanders (FWO; 1S74619N). L.R. and B.M. are funded by Ghent University and M.B., S.S., K.T., F.V.M. and A.D. are supported by Ghent University Hospital. Research in the N.C. lab was funded by Ghent University, VIB and Kom op Tegen Kanker. A.D.K and N.C. are co-inventors of patent WO2017162754A1. The other authors have no conflicts of interest. N/A.

Prenatal diagnosis of a novel 7q31.31q31.33 microduplication with a favorable outcome

BackgroundCopy number variants (CNVs) are an important source of normal and pathogenic genome variations. Especially CNVs identified in prenatal cases need careful considerations and correct interpretation if those are harmless or harmful variants from the norm.Case presentationHerein, we reported a paternally inherited duplication of 7.6 Mb in 7q31.3 with, surprisingly, a favorable outcome. GTG-banding and CMA on the DNA derived from uncultured amniocytes revealed a karyotype: 46,XX.arr[GRCh37] 7q31.31q31.33(118,601,001_126,177,044) × 3. Ultrasound examination showed no dysmorphisms or intrauterine growth restriction in the fetus and the father was clinically normal as well.ConclusionPrenatal detection of a 7.6 Mb in 7q31.31 to 7q31.33 duplication in a female fetus turned out to be a yet unreported unbalanced chromosome abnormality. This is another example that parental testing and GTG-banding are necessary additional tests to be done in prenatal cases, before a reliable conclusion on the meaning of an aberration can be drawn.

Detection of aneuploidy using multiplex ligation–dependent probe amplification in fetal tissues from aborted pregnancies

Purpose: About 10-15% of all pregnancies terminate as spontaneous miscarriages. In the first trimester, ≈50% of spontaneous miscarriages are the result of chromosomal aberrations, mostly chromosomal aneuploidies. Cytogenetic analyses are used to confirm aneuploidy in failed pregnancies. Culture failure or poor-quality chromosomes are often problems in those cases. In such situations, methods that are independent of tissue culture are used, and we employed multiplex ligation-dependent probe amplification (MLPA). We determined if MLPA is an appropriate and compatible method compared with classical cytogenetic analyses on fetal tissues.&#x0D; Methods: All fetal samples received from spontaneous abortions were cultured, karyotyped (if possible) and genomic DNA extracted. MLPA analyses were undertaken using subtelomeric probe kits. Additionally, comparative genomic hybridization (CGH) was used to confirm aneuploidy detected by MLPA in cases of failed culture growth.&#x0D; Results: MLPA analyses confirmed an unbalanced chromosome abnormality identified by cytogenetic analyses in all cases in which tissue culture was successful, and provided data in cases of failed culture growth. Several common numeric chromosome aberrations were detected, as well as rare trisomies and other unbalanced chromosome rearrangements.&#x0D; Conclusions: MLPA analyses can provide information about the karyotype of a DNA sample if cytogenetic analyses are not possible because of a lack of viable cells or if only a small amount of genomic DNA is available. Th

Parental balanced chromosomal rearrangement leading to major genomic imbalance and an autosomal trisomy resulting in consecutive pregnancy loss: a case report

Chromosomal aberrations such as parental balanced translocation contribute to a significant proportion of recurrent pregnancy losses. These have extreme genetic implications on the foetus which can either cause physical and/or mental retardation or early death. In this study, we report a unique clinical case of a couple with three consecutive pregnancy losses and we aim to determine the genetic abnormalities causing the miscarriages. Conventional cytogenetic and molecular genetic analysis were performed on the products of conception as well as for the parents. Chromosomal analysis was performed based on the ISCN 2016 guidelines. This was followed by Chromosomal microarray analysis carried out using ISCA consortium probe set (8X60K). Genetic testing for the 1st product of conception was not performed. However, the 2nd and 3rd products of conception indicated an autosomal trisomy 22 and a 3.7 Mb deletion of 2p (cytoband p25.3) along with 13.6 Mb duplication of 16p (cytoband p13.3p13.12), respectively. The paternal karyotype was normal but mother showed a balanced translocation 46,XX,t(2;16)(p25.3;p13.3). This was parallel to the products of conception microarray findings, unbalanced chromosomal abnormality in the foetus. Balanced translocation carriers are susceptible for meiotic nondisjunction processes and early detection of genetic anomalies can be informative to parents trying to conceive. Genetic analysis of the abortus after the 1st loss can be helpful to understand the cause of miscarriage. A combined approach with microarray and karyotyping of the products of conception can be important to determine the specific aberrations in the foetal chromosomes leading to abortion.

Detection of cytogenomic abnormalities by OncoScan microarray assay for products of conception from formalin-fixed paraffin-embedded and fresh fetal tissues

BackgroundThe OncoScan microarray assay (OMA) using highly multiplexed molecular inversion probes for single nucleotide polymorphism (SNP) loci enabled the detection of cytogenomic abnormalities of chromosomal imbalances and pathogenic copy number variants (pCNV). The small size of molecular inversion probes is optimal for SNP genotyping of fragmented DNA from fixed tissues. This retrospective study evaluated the clinical utility of OMA as a uniform platform to detect cytogenomic abnormalities for pregnancy loss from fresh and fixed tissues of products of conception (POC).ResultsFresh specimens of POC were routinely subjected to cell culture and then analyzed by karyotyping. POC specimens with a normal karyotype (NK) or culture failure (CF) and from formalin-fixed paraffin-embedded (FFPE) tissues were subjected to DNA extraction for OMA. The abnormality detection rate (ADR) by OMA on 94 cases of POC-NK, 38 cases of POC-CF, and 35 cases of POC-FFPE tissues were 2% (2/94), 26% (10/38), and 57% (20/35), respectively. The detected cytogenomic abnormalities of aneuploidies, triploidies and pCNV accounted for 50%, 40% and 10% in POC-CF and 85%, 10% and 5% in POC-FFPE, respectively. False negative result from cultured maternal cells and maternal cell contamination were each detected in one case. OMA on two cases with unbalanced structural chromosome abnormalities further defined genomic imbalances and breakpoints.ConclusionOMA on POC-CF and POC-FFPE showed a high diagnostic yield of cytogenomic abnormalities. This approach circumvented the obstacles of CF from fresh specimens and fragmented DNA from fixed tissues and provided a reliable and effective platform for detecting cytogenomic abnormalities and monitoring true fetal result from maternal cell contamination.

Prognostic Impact of the Latency Time from the Administration of Cytotoxic Therapy to the Development of Therapy-Related Myeloid Neoplasms

Introduction: Among Therapy-Related Myeloid Neoplasms (t-MNs), there are two large groups depending on the cytotoxic trigger. A first group arises after exposure to alkylating agents and / or radiation in the previous 5-10 years and it is associated with unbalanced chromosomal abnormalities, frequently with alterations in Cr 5, 7, complex karyotype and mutated TP53. The second arises after exposure to topoisomerase II inhibitors in the previous 1-5 years, and it is characterized by frequent balanced translocations and KMT2A rearrangement. In those cases with a latency time from cytotoxic exposure to T-MNs diagnosis greater than 10 years, there is doubt about whether they should be considered T-MNs or de novo leukemias. Material and methods: We performed a retrospective analysis of 34 patients with diagnosis of T-MNs treated in our center between 2013 and 2019. We have reviewed the cytogenetic alterations at diagnosis and alterations in TP53 and / or 17p and rearrangements in KMT2A. We divided the cohort into two groups based on the latency time of ≤10 years or&amp;gt; 10 years. The comparison between both groups was carried out using the chi2 test for qualitative variables and the t-student for quantitative variables. The Kaplan Meier method has been used for the calculation of Overall Survival (OS) and Event Free Survival (EFS) and the Cox regression model for the univariate and multivariate analysis. Results: The median follow-up of the global cohort was 8.5 months (0-74). The median OS of the global cohort was 10 months and the EFS was 8 months. In patients with a latency time ≤10 years the median OS was 12 months vs 9 months in those with latency &amp;gt;10 years, with a Hazard Ratio (HR) of 0.6 [95% CI (0.2-1.7), p = 0.3] and the EFS was 7 months vs 9 months respectively [HR 0.3, 95% CI (0.3-1.8), p = 0.7]. The baseline characteristics of the population are reflected in Table 1. A similar percentage of patients with complex or monosomal karyotype at diagnosis is observed in both groups, as well as alterations in TP53 and/or 17p. In the &amp;gt;10-year latency subgroup, there were no patients with prior exposure to Topoisomerase II Inhibitors. Within the &amp;lt;10-year latency group, we divided the cohort into two groups: 1 to 5 years and 5 to 10 years of latency. No differences were found for OS [HR 1.5 95% CI (0.4-5), p = 0.4] or for EFS [HR 2.1 95% CI (0.7-6.2), p = 0.1]. A univariate analysis was performed including the characteristics reflected in Table 2. The variables with a significant HR for OS and EFS were to present a monosomic karyotype at diagnosis and alterations in TP53 and/or 17p. In the multivariate analysis, only the alterations in TP53 and/or 17p maintained a significant HR. Conclusions: Patients with a latency time from exposure to cytotoxic therapy to the diagnosis of T-MNs &amp;gt; 10 years, presented cytogenetic and molecular characteristics similar to those with an exposure time ≤10 years, as well as a similar OS and EFS. Regarding the cytogenetic characteristics at diagnosis of the general cohort, patients with monosomic karyotype and especially those with TP53 and/or 17p alterations had a worse prognosis. Disclosures Garcia-Gutiérrez: Incyte:Consultancy, Other: Travel, Accommodation, Expenses, Research Funding;Novartis:Consultancy, Other: Travel, Accommodation, Expenses, Research Funding;Bristol-Myers Squibb:Consultancy, Other: Travel, Accommodation, Expenses, Research Funding;Pfizer:Consultancy, Other: Travel, Accommodation, Expenses, Research Funding.

M170. GENETIC CHARACTERIZATION OF A COHORT OF PATIENTS AFFECTED BY SCHIZOPHRENIA. THE ROLE FOR RARE STRUCTURAL VARIANTS IN MODULATING TREATMENT RESISTANT ENDOPHENOTYPES: PRELIMINARY DATA

BackgroundSchizophrenia (SCZ) is a debilitating mental illness characterized by a highly complex, heterogeneous, non-mendelian genetic background. Recent progress in dissecting genetic architecture of SCZ has accelerated over the last decade due to new advanced technologies. Genome-Wide Association Studies (GWAS) on extremely large samples of patients identified and replicated hundreds of Single-Nucleotide Polymorphism (SNPs), each exhibiting only a modest effect. The analysis of genomic Copy Number Variations (CNVs) clarified the role of rare structural variants conferring significant risk by disrupting multiple genes involved in neurodevelopmental pathways, and linked to SCZ. In this scenario, the aim of our study is to carry out a genetic characterization of a cohort of patients affected by SCZ, in order to assess the risk of recurrence, to elucidate putative pathogenetic mechanisms and, whenever possible, to conceive tailored interventions and therapies.Methods34 patients (8 women and 26 men) affected by SCZ and admitted to Day Hospital at Psychiatric Division for Treatment Resistant Psychosis of the University of Naples Federico II were recruited, and underwent: i) psychopathological evaluation and assessment of clinical response to antipsychotics; ii) genetic counseling; iii) further diagnostic investigation by using Comparative Genomic Hybridization (CGH) + Single Nucleotide Polymorphism (SNP) microarray with 2x400k Agilent’s platform “GenetiSure” for detecting unbalanced chromosomal abnormalities and regions of homozygosity (ROHs).ResultsStructural pathogenetic rearrangements resulted in 9 (27%) patients. Those identified were the following: 15q13.3 deletion, 16p13.11 duplication, 22q11.22 deletion (TOP3B), 22q11.22 (PRODH, DGCR5, DGCR6), RBFOX1 deletion, TCF4 deletion, derivative X chromosome (X;Y translocation).Potentially pathogenic rearrangements, involving genes associated with psychiatric disorders or implicated in neurodevelopment, resulted in 15 patients (44%).No relevant CNVs were detected in 10 patients (29%), although they showed the presence of ROHs that may contain susceptibility loci, since many neurodevelopmental genes map onto or near these specific regions.Certain of these rearrangements occur in many patients, and certain patients showed likewise multiple rearrangements.DiscussionThe analysis of CNVs and SNPs allowed us to characterize the genetic disease structure in the whole cohort of patients and helped to refine the diagnosis in a few cases, thereby ascertaining an underlying specific genetic condition. A further extension of the study, in terms of sample size and more accurate investigations (i.e genetic mapping of ROHs) is underway. According to literature, rare risk-associated CNVs account for 2% of SCZ cases, but their higher prevalence (27%) in our sample may be influenced by a larger percentage of Treatment Resistant and more severely ill patients (since they were recruited in a highly specialized Unit for Treatment Resistant Psychosis). Therefore, our future purpose is to demonstrate a robust genetic modulation of Treatment Resistant endophenotypes of SCZ.Moreover, we believe that the role of genetic counseling in psychiatric services should be emphasized, and that genetic testing in this field should not be restricted to suspected childhood neuropsychiatric disorders. According to the neurodevelopmental hypothesis of SCZ, that suggests a brain development disruption in early life (due to genetic and early environmental factors), prompting to a subsequent later emergence of the disease in adulthood, even chronic complex adult mental illness, such as SCZ, deserves detailed investigations and a more exhaustive genetic evaluation.

Three Offspring with Cri-du-Chat Syndrome from Phenotypically Normal Parents

Cri-du-chat syndrome is characterized by facial dysmorphism, intellectual disability, and multiple congenital anomalies. Most cases occur de novo. Here, we report 3 siblings with cri-du-chat syndrome born to healthy parents. The proband was admitted to our clinic at the age of 6.5 years due to severe intellectual disability, facial dysmorphism, and heart defect. His karyotype showed a deletion of chromosome 5p. Microarray analysis revealed a 29-Mb deletion in chromosome 5p and a 4.7-Mb duplication in chromosome 19q. FISH analysis indicated an unbalanced translocation between 5p13.3 and 19q13.4. During follow-up, the second and the third child of the family were born with the same chromosome abnormality. Parental peripheral blood and skin fibroblast karyotypes as well as the FISH results using chromosome 5p- and 19q-specific subtelomeric probes were normal. FISH analysis of the father's sperm detected a 5p deletion in 12.8% of 200 cells, and microarray analysis confirmed the same unbalanced chromosome abnormality in a mosaic pattern. Uncultured peripheral blood and buccal smear of the father were also studied by FISH to exclude low-level mosaicism and in vitro culture effect. This is the first study that provides molecular evidence of paternal gonadal mosaicism of an unbalanced translocation detected in 3 siblings with cri-du-chat syndrome.

Хромосомный микроматричный анализ абортивного материала

Цель исследования - оценить распространенность и типы хромосомных аномалий (ХА) в абортивном материале за период с 2015 по 2019 гг. Методом хромосомного микроматричного анализа был исследован 2201 образец ДНК, выделенной из абортивного материала при неразвивающейся беременности. ХА были обнаружены в 49,57% случаев, из них анеуплоидии, в том числе нескольких хромосом и мозаичные формы, составляют 79,65%, триплоидия - 10,72%, другие ХА, возможно имеющие клиническое значение, - 8,62%, тетраплоидия - 1,01%. Таким образом, хромосомный микроматричный анализ может быть рекомендован как рутинный метод для поиска несбалансированных ХА в абортивном материале при невынашивании беременности. Study objective is to assess the prevalence and pattern of chromosomal abnormalities (CAs) in products of conception (POC) for the period from 2015 to 2019. Materials and Methods: 2201 samples of POC were studied by the chromosomal microarray analysis. Study Results: CAs were detected in 49.57% of cases, of which aneuploidy, including several chromosomal and mosaic forms, were detected in 79.65%, triploidy - 10.72%, other CAs with possible clinical significance - 8.62%, tetraploidy - 1.01%. Conclusion: chromosomal microarray analysis can be recommended as a routine method for searching of unbalanced CAs in POC.

Cost‐effectiveness of five prenatal screening strategies for trisomies and other unbalanced chromosomal abnormalities: model‐based analysis

To evaluate the cost-effectiveness of five prenatal screening strategies for trisomies (13/18/21) and other unbalanced chromosomal abnormalities (UBCA), following the introduction of cell-free DNA (cfDNA) analysis. A model-based cost-effectiveness analysis was performed to estimate prevalence, safety, screening-program costs and healthcare costs of five different prenatal screening strategies, using a virtual cohort of 652 653 pregnant women in France. Data were derived from the French Biomedicine Agency and published articles. Uncertainty was addressed using one-way sensitivity analysis. The five strategies compared were: (i) cfDNA testing for women with a risk following first-trimester screening of ≥ 1/250; (ii) cfDNA testing for women with a risk of ≥ 1/1000 (currently recommended); (iii) cfDNA testing in the general population (regardless of risk); (iv) invasive testing for women with a risk of ≥ 1/250 (historical strategy); and (v) invasive testing for women with a risk of ≥ 1/1000. In our virtual population, at similar risk thresholds, cfDNA testing compared with invasive testing was cheaper but less effective. Compared with the historical strategy, cfDNA testing at the ≥ 1/1000 risk threshold was a more expensive strategy that detected 158 additional trisomies, but also 175 fewer other UBCA. Implementation of cfDNA testing in the general population would give an incremental cost-effectiveness ratio of €9 166 689 per additional anomaly detected compared with the historical strategy. Extending cfDNA to lower risk thresholds or even to all pregnancies would detect more trisomies, but at greater expense and with lower detection rate of other UBCA, compared with the historical strategy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Complex karyotype in de novo acute myeloid leukemia: typical and atypical subtypes differ molecularly and clinically.

Complex karyotype (CK) with ≥3 abnormalities is detected in 10-12% of patients with acute myeloid leukemia (AML) and associated with poor prognosis. The most common unbalanced abnormalities found in CK result in loss of material from the 5q, 7q and/or 17p chromosome arms. The presence of 5q, 7q and/or 17p abnormalities denotes typical CK and their absence denotes atypical CK. Since molecular features of CK-AML are not well-characterized, we investigated mutational status of 81 leukemia/cancer-associated genes in 160 clinically well-characterized patients. They included 136 patients with ≥3 exclusively unbalanced chromosome abnormalities, 96 of whom had a typical CK and 40 atypical CK, and 24 patients with ≥1 balanced abnormality in addition to ≥2 unbalanced ones. Patients with atypical CK-AML differed from those with typical CK-AML: they carried TP53 mutations less often (P<0.001) and more often PHF6 (P=0.008), FLT3-TKD (P=0.02), MED12 (P=0.02) and NPM1 (P=0.02) mutations. They were younger (P=0.007), had higher WBC (P=0.001) and percentages of marrow (P<0.001) and blood (P=0.006) blasts, higher complete remission rates (P=0.02) and longer overall survival (P<0.001), thus indicating that atypical and typical CK-AMLs constitute distinct disease subtypes. We also identified smaller patient subsets within both typical and atypical CK-AML that differed molecularly and clinically.