Monosomy Of Chromosome Research Articles

Unequal distribution of genes and chromosomes refers to nuclear diversification in the binucleated Giardia intestinalis

The single-celled parasite Giardia intestinalis (Diplomonadida) has two equally sized nuclei in one cell. The nuclei have been considered identical. We have previously shown that they contain different chromosomal sets and proceed through the cell cycle with some asynchrony. Here, we demonstrate by fluorescence in situ hybridization that several genes from chromosome 5 are lost in one of the two nuclei of the WBc6 Giardia line. The missing segment stretches over at least 50 kb near the 5′ chromosome end. In both WB and WBc6 Giardia cell lines, chromosome 5 is trisomic in one nucleus and monosomic in the other nucleus. The described chromosomal deletion has always been observed at the monosomic chromosome in WBc6; however, the deletion was not detected in the parent line WB. The chromosomal segment was thus initially lost after biological cloning of WB, which gave rise to clone WBc6. We show that Giardia is capable of carrying out gene expression from only one nucleus. The two nuclei display a certain level of diversity, making each of them irreplaceable. The doubled karyomastigonts of diplomonads likely have separate functions both in the mastigont/flagellar organization and in chromosomal and gene content. To our knowledge, our results offer the first methodical approach to differentiating the two, so far indistinguishable nuclei.

Cognitive and Behavioral Functioning Among Fraternal Twins with an Unbalanced Translocation of Chromosomes 10q and 12p: A Case Report

Because neurodevelopmental disorders, such as autism spectrum disorder, intellectual disability, and language disorder, are genetically heterogeneous, there is a need for exploring their many pathways, and case studies provide a means to do so in rare conditions. We present a case study describing fraternal twins with an unbalanced translocation, resulting in a partial trisomy of chromosome 10 (q24.1) and a partial monosomy of chromosome 12 (p13). The twin’s father, a healthy individual with typical development, was found to have a balanced translocation between chromosomes 10q and 12p. Although a handful of cases have described individuals with only trisomies of chromosome 10q or only monosomies of chromosome 12p, none have examined children with both chromosomal aberrations. We describe the children’s cognitive and behavioral phenotype (including autism spectrum disorder, moderate intellectual disability, and language disorder), discuss a possible genetic mechanism contributing to their comorbidities (i.e., 12p13 microdeletions), and review other potential contributing factors to their presentation.

Comparison of Efficiencies of Non-invasive Prenatal Testing, Karyotyping, and Chromosomal Micro-Array for Diagnosing Fetal Chromosomal Anomalies in the Second and Third Trimesters.

In this study, we aimed to compare the efficiency of non-invasive prenatal testing (NIPT), karyotyping, and chromosomal micro-array (CMA) for the diagnosis of fetal chromosomal anomalies in the second and third trimesters. Pregnant women, who underwent amniocenteses for prenatal genetic diagnoses during their middle and late trimesters, were recruited at the Prenatal Diagnosis Center of Taizhou City. Maternal blood was separated for NIPT, and amniotic fluid cells were cultured for karyotyping and CMA. The diagnostic efficiency of NIPT for detecting fetal imbalanced anomalies was compared with karyotyping and CMA. A total of 69 fetal chromosomal imbalances were confirmed by CMA, 37 were diagnosed by NIPT and 35 were found by karyotyping. The sensitivities of NIPT and karyotyping for diagnosing aneuploidy were 96.3% and 100% respectively. Only one mosaic sexual chromosome monosomy was misdiagnosed by NIPT, whereas the sensitivity of NIPT and karyotyping was 70% and 30%, respectively, for detecting pathogenic deletions and duplications sized from 5–20 Mb. Taken together, our results suggest that the efficiency of NIPT was similar to the formula karyotyping for detecting chromosome imbalance in the second and third trimesters.

Epigenetics and genomics in Turner syndrome.

The pathogenesis of Turner syndrome (TS) and the genotype-phenotype relationship has been thoroughly investigated during the last decade. It has become evident that the phenotype seen in TS does not only depend on simple gene dosage as a result of X chromosome monosomy. The origin of TS specific comorbidities such as infertility, cardiac malformations, bone dysgenesis, and autoimmune diseases may depend on a complex relationship between genes as well as transcriptional and epigenetic factors affecting gene expression across the genome. Furthermore, two individuals with TS with the exact same karyotype may exhibit completely different traits, suggesting that no conventional genotype-phenotype relationship exists. Here, we review the different genetic mechanisms behind differential gene expression, and highlight potential key-genes essential to the comorbidities seen in TS and other X chromosome aneuploidy syndromes. KDM6A, important for germ cell development, has shown to be differentially expressed and methylated in Turner and Klinefelter syndrome across studies. Furthermore, TIMP1/TIMP3 genes seem to affect the prevalence of bicuspid aortic valve. KDM5C could play a role in the neurocognitive development of Turner and Klinefelter syndrome. However, further research is needed to elucidate the genetic mechanism behind the phenotypic variability and the different phenotypic traits seen in TS.

Poor overall survival in hyperhaploid multiple myeloma is defined by double-hit bi-allelic inactivation of TP53.

Hyperhaploid multiple myeloma is a rare numerical aberration group defined by a range of 24-34 chromosomes, which is associated with a poor prognosis with a 5-year survival rate of 23%. Hyperhaploid patient samples (n=8) were sequenced and copy number and mutations identified. Samples had a median of 13 monosomies (range 12-14), which in general were those not associated with trisomies in hyperdiploid samples. The chromosomes traditionally trisomic in hyperdiploid myeloma were disomic in hyperhaploid myeloma with retention of heterodisomy. We examined the hyperhaploid samples for frequently mutated genes and found that 8/8 (100%) hyperhaploid samples had a mutation in TP53, exceeding the overall rate of mutation in newly diagnosed patients (5.5%), indicating an oncogenic dependency in this group. All samples with TP53 mutation also had monosomy of chromosome 17, indicating bi-allelic inactivation of TP53. As such, this high risk group is part of double-hit myeloma.

Cytogenetic Abnormalities in Multiple Myeloma Patients at a Tertiary Healthcare Center in India

Objective:Multiple myeloma (MM) is a clinically and genetically heterogeneous plasma cell neoplasm. The prognosis of MM patients is dependent on several factors including the patient’s age, the stage of disease and genetic alterations. This study aimed to determine the frequency of common chromosomal abnormalities and their significance in MM patients referred to a tertiary healthcare center in India.Methods:Fluorescence in situ hybridization on interphase nuclei from bone marrow cells using seven MM-specific probes for recurrent aberrations was performed in a total of 215 newly diagnosed patients.Results:Chromosomal abnormalities were detected in 161 (74.9%) MM patients in this study. The most frequent aberration was trisomy(ies) involving only gain of chromosomes in 48 (22.3%) cases. A translocation involving the IGH gene alone or accompanied by trisomy(ies) or by monosomy 13/13q deletion or by both was registered in 80 (37.2%) patients. Atypical patterns such as a deletion of the IGH variable segment (IGHv) on the derivative chromosome 14 or on the native (normal) chromosome 14, biallelic deletion of IGHv, deletion of the IGH constant segment on the rearranged chromosome14 and extra fusions were noticed in 21 (9.8%) patients with an IGH rearrangement. Monosomy 13/deletion 13q was identified singly or as part of a complex karyotype in 74 patients (34.4%). Clonal heterogeneity and additional abnormalities including TP53 deletion and monosomies of chromosomes 4, 9, 14 and 16 were recorded in 18.6% and 16.3% of patients respectively. Patients with abnormalities exhibited plasmacytosis, reduced hemoglobin value and high level of ß2-microglobulin.Conclusions:A lower median age and a low frequency of IGH translocations particularly t(11;14) and chromosome 13 abnormalities suggest ethnic diversity. Further investigations on genetic alterations including IGH deletions will contribute to improved insights into the biology of myeloma disease, risk stratification and patient management.

Predictive Analysis on Prognostic Impact of Monosomy 7 in AML and Identified Therapy Options for This Cohort

Background: Monosomy of chromosome 7/Del 7 (-7) or its long arm (del(7q)) is one of the most common cytogenetic abnormalities in pediatric and adult myeloid malignancies, particularly in adverse-risk acute myeloid leukemias (AMLs). Monosomy 7 with complex karyotype further worsens the prognosis. Therefore, predicting response of therapies in this segment of patients is urgently needed to improve disease management by customizing therapy to the profile genomics instead of the conventional method of trial and error or one-size-fits all treatments.Aim: Predictive analysis of disease characteristics of Monosomy 7 and Sub-clustering of this segment along with identification of therapy options for treatment of this cohort using computational biology modeling (CBM).Methods: We selected a cohort of 1168 AML patients whose genomics and clinical data was collated from public domain datasets and literature. Using CBM, patients with (-7) were identified from this larger cohort and were sub-clustered using a machine learning approach.The genomic data of the representative patients per sub-cluster of (-7) cohort were used to generate disease-specific protein network maps. Digital drug simulations were done by quantitatively measuring drug effect and calculating a disease inhibition score (DIS) that is a composite of proliferation, viability and apoptosis along with impact on disease specific biomarker score. Each patient-specific map was digitally screened for the extent by which standard of care (SOC) and combinations with Non-SOC inhibited the disease.Results: CBM identified 187 (-7) patients (16%) that grouped into 8 sub-clusters (Table 1). CBM analysis of genomics of each sub-cluster representative identified combination therapy options for this cohort with poor response to SOC, supported by genomics driven disease characteristics.Monosomy 7 aberrations would lead to decreased expression of EZH2, CARD11, EIF3, PMS2, HUS1, KMT2C (MLL3), CDK5 and IKZF1. Azacitidine (AZA) is predicted to be a non-responder in this cohort due to decreased expression of EZH2, that would impact DNA methylation via reduced recruitment of DNMTs. Lenalidomide (LEN) is also predicted to be a non-responder due to decreased expression of IKZF1, CARD11, and EIF3 despite presence of Del5q, a strong inclusion for LEN response.This segment has shown high microsatellite instability (MSI) characteristics and this could be linked to reduced mismatch repair (MMR) pathway due to reduced expression of PMS2, HUS1 and KMT2C. This characteristic could explain certain patient cases with (-7) who have responded to Cytarabine. (Figure 1) However, the response rate of chemotherapy in (-7) cohort is <50% and relapse is high. (PMID 12393746) Loss of histone methyltransferase EZH2 through reduction of H3K27 trimethylation can be the key reason for inducing resistance to many AML cytotoxic drugs.With (-7), CBM analysis determined an increased expression of BCL2 due to reduced methylation and HOXA9 expression. (PMID: 9562974) Proteasomal subunit PSMB5 gets down regulated due to CDK5 loss which would make the cohort more sensitive to proteasomal inhibition. This can also help with controlling EZH2 levels in the disease via regulating EZH2 proteasomal degradation. (PMID: 21289309, 27941792) CBM predicted that a combination of Cytarabine + Bortezomib and Cytarabine + Venetoclax could be effective in the (-7) AML cohort.Conclusions: CBM analysis of AML patient genomics identified abnormal protein networks and drug resistance pathways in patients with monosomy 7, and combination therapy options in the (-7) sub-clusters. EZH2 was identified as a key reason for resistance and combinations of Cytarabine with proteasome or BCL2 inhibitor was predicted to be effective in this cohort. [Display omitted] DisclosuresVali:Cell Works Group Inc.: Employment. Cogle:Celgene: Other: Steering Committee Member of Connect MDS/AML Registry. Singh:Cellworks Research India Private Limited: Employment. Usmani:Cellworks Research India Private Limited: Employment. Pampana:Cellworks Research India Private Limited: Employment. Shyamasundar:Cellworks Research India Private Limited: Employment. Sikora:Cellworks Research India Private Limited: Employment. Kumar:Cellworks Research India Private Limited: Employment. Abbasi:Cell Works Group Inc.: Employment.

Aplastic Anemia in the Elderly: A Nationwide Survey on Behalf of the French Reference Center for Aplastic Anemia

▪IntroductionAplastic anemia (AA) is a rare but potentially life-threatening disease that frequently occurs in older patients. Various therapeutic options can be proposed and data regarding the ideal first line treatment of AA in this ageing population remains scarce.MethodsWe conducted a retrospective nationwide multicenter study in France to examine current treatments for AA patients over 60 years old within a 10-year period (1/1/2007 to 12/31/2016). Our aims were to evaluate efficacy and tolerance of AA treatment, and to analyze predictive factors for response and survival. Patients who were diagnosed with AA by a bone marrow biopsy at the age of 60 or over were included in the study.ResultsOver the course of a decade, 88 patients (median age 68.5) were identified in 19 centers, with a median follow-up of 32.1 months; 49% were women, the median Charlson comorbidity index was 2 (range 0-6), the median performance status was 1 (range 0-3), 21% had very severe (vSAA) and 36% severe AA. We analyzed 184 treatment lines which comprised ATG-CsA (33%, including 72% with horse ATG), CsA alone (14%), androgen alone (14%), eltrombopag alone (10%), CsA associated with androgen or eltrombopag (9%), and other treatments (20%). First-line treatment was ATG-CsA for half of patients. Comparisons of patients treated in first line with ATG-CsA, CsA or other treatments revealed that patients receiving ATG-CsA were significantly younger (66 years, vs. 71.5 vs. 71.5, respectively, p=0.007), more frequently female (61%, vs. 50% vs. 27%, p=0.02) and had a lower platelet count (8x109/L, vs. 12x109/L vs. 15x109/L, p=0.025). We found no difference with respect to weight, Charlson comorbidity index score, performance status or disease severity between first line treatment regimens. After first-line therapy, 32% of patients achieved a complete response (CR), and 15% a partial response (PR). After the 181 assessable treatment lines, 19% achieved CR and 19% a PR. Median time until best response was 151 days. The overall response rate (ORR) was 62% with ATG-CsA (70% as a first-line treatment), 35% with CsA alone (39% as first-line), 22% with eltrombopag, and 21% with androgen. The ORR in patients over 70 years receiving ATG-CsA (n=16) was 81% (50% achieving a CR). Responses were significantly better in first line and in patients with good performance status, as well as in those that had received ATG-CsA (ORR of 70% after first-line treatment). In a multivariable analysis using ATG-CsA as a baseline, we found that CsA alone (OR 0.35 (0.13;0.96), p=0.042), eltrombopag (OR 0.12 (0.03;0.54), p=0.0057) and androgens (OR 0.17 (0.05;0.58), p=0.0047) were all individually associated with lower response rates. The main complications were infections (grade III/IV, 35% of treatment lines including 9 deaths (5%)), and renal issues (grade-III/IV, 29%). ATG-CsA was associated with significantly more infectious complications (72% vs. 24%, p<0.0001), cardiovascular complications (32% vs. 15%, p=0.01) and acute kidney failure (43% vs. 22%, p=0.003) than other treatments. Patients aged 70 and over receiving ATG-CsA did not experience more complications than younger patients. Four clonal evolutions were recorded: two abnormal karyotypes (1 monosomy of chromosome 7 and 1 t(3;4)), one case of acute myeloid leukemia, and one case of myelodysplastic syndrome with 17% excess blasts. Three-year survival was 74.7% (median survival 7.36 years, Figure) and 24 patients died (nine infections, five deaths in palliative care or after active treatment had finished, four hemorrhagic complications, and six miscellaneous causes). Age (OR 1.07 (1.01;1.14), p=0.03), Charlson comorbidity index (HR 1.34 (1.07;1.67), p=0.01) and vSAA (HR 3.67 (1.51;8.91), p=0.004) were independently associated with mortality.ConclusionOur study showed a significantly better ORR with ATG-CsA than other regimens for treatment of AA in elderly, with more complications but no more death. Age per se is not a limiting factor for treatment with ATG-CsA: this regimen should be used as first-line treatment in elderly patients if they have a good performance status and low comorbidity index score. Among patients with adverse performance status or comorbidities contra-indicating the use of ATG, CsA alone or in combination may be safely used. Other strategies might be reserved for later courses of treatments. Supportive care may have a great impact on survival in this population. [Display omitted] DisclosuresAdes:JAZZ: Honoraria; Takeda: Membership on an entity's Board of Directors or advisory committees; silent pharma: Consultancy; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Peffault De Latour:Pfizer Inc.: Consultancy, Honoraria, Research Funding; Amgen Inc.: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding.

Biology of Acute Myeloid Leukemia (AML) with Monosomy of Chromosome 7 or Loss of 7q. a Study on 487 Patients Analyzed By Gene Expression Profile (GEP), Single Nucleotide Polymorphism (SNP) Arrays and Metabolomics

Biology of Acute Myeloid Leukemia (AML) with Monosomy of Chromosome 7 or Loss of 7q. a Study on 487 Patients Analyzed By Gene Expression Profile (GEP), Single Nucleotide Polymorphism (SNP) Arrays and Metabolomics

Transcriptomic Profile Identified a Specific Signature in Children with Acute Myeloid Leukemia (AML) and Primary Induction Failure (PIF): Preliminary Data and Future Perspectives

Background. Acute Myeloid Leukemia is a heterogeneous disease, characterized by the uncontrolled proliferation of hematopoietic precursor cells. AML accounts for 15% of acute leukemias in children, with a cure rate of 55-60% as overall survival (Pession A Blood 2013). Complete remission (CR) is achieved in 80-85% of children with AML. Current protocol defines CR by morphological evaluation (blasts <5%) and cytofluorimetric analyses (blasts <0,1%), after two cycles of high-dose chemotherapy. Around 10-15% of children and 30% of adults do not achieve remission and are defined as Primary Induction Failure (PIF). The majority of these cases are addressed to other form of high-dose chemotherapy blocks, experimental therapies or directly to hematopoietic stem cell transplantation (HSCT) as salvage treatment, showing a very poor prognosis (Quarello P et al. British Journal of Haematology 2015). Strong efforts to generate biological data in order to define this subtype of AML are needed for early identification and for target therapy design.Aim. Our study aims to characterize a specific gene-expression profile in children with PIF-AML in order to early detect peculiar genetic aberrations and to identify potential targets to new compounds.Materials and Methods. We analyzed diagnostic samples from 4 children with PIF-AML, diagnosed and treated in our Center, from 2013 to 2016. All cases were female and 3 had more than 10 years of age. One presented with a monosomy of chromosome 11; two with complex karyotype (one with NUP98-NSD1 rearrangement) and one with no cytogenetic and molecular markers. After two cycles of Induction phase, one case showed complete blast regeneration (>60%); in the other three cases we detected, by flow-cytometry, a blast rate between 10-20%. In the attempt to compare these cases with those presenting with very high-risk (VHR) features but achieving CR after induction (Primary Induction Responder, PIR), we included in our analyses 8 children with VHR-PIR-AML, diagnosed and treated in our Center: 2 with FLT3-ITD and NUP98-NSD1 fusion genes; 2 with FLT3-ITD and complex karyotype; 2 with DEK-CAN fusion genes (1 with FLT3-ITD); 2 with NUP98 rearrangements and complex karyotype. We performed whole transcriptome analyses using Human Transcriptome Array 2.0 (Affymetrix). Then we compared our analyses with a recently published data set, including a large population of children with AML (Bisio V Leukemia 2017). Based on transcriptomic findings, we determined the expression of specific genes, by Real-time PCR using gene-specific probes (UPL probes by Roche Merck, Germany), applying a QuantStudio7 Flex System technology (Applied Biosystem, California, USA) and the relative quantification method (the comparative 2-ΔΔCt method). We applied a t-student test, for statistical analyses among different subgroups.Results. A direct comparison of PIF-AML vs PIR-AML subgroups revealed 919 protein-coding and 8 pri-miRNA overexpressed genes (fold-change >3, FDR adjusted p value <0.05) and 18 protein coding and 43 pri-miRNA down-regulated genes (fold-change >-3, FDR adjusted p value <0.05). Marked differences were observed in cancer-related genes such as KIT, PTEN, FLT3 and POU4F1, and in cell-cycle related genes such as cyclin transcripts (CNNG1, CCNA1, CCND2, CCNJ, CCNC, CCNY). Moreover some genes that discriminate PIF from PIR subgroups are also differentially expressed between cases with NUP98-negative and NUP98-positive AML (PDGFD, CCNA1). The latter group is considered as a VHR-AML subtype. Based on these findings, we selected several genes including HOX-B3, HOX-B5, CEBP-D, CCNA1, PDGF-D and performed a Real-Time PCR with specific-gene probes. Comparing gene expression data of our 4 PIF-AML cases with 8 VHR-PIR-AML cases, we observed a strong statistically significant different expression in CCNA1 (p<0.0001) and PDGF-D (p<0.0001).Conclusions. Our findings defined a characteristic profile of PIF-AML, highlighting the overexpression of cell-cycle related genes (CCNG1, CCNA1) and several potential targets (KIT, FLT3, PDGF-D) to be considered for an alternative treatment in this very poor-prognostic subgroup of patients. In conclusion our results suggest that PIF-AML samples bear a specific gene expression profile, not overlapping with those of known molecular and karyotype AML subgroups. However, a larger population study is needed to confirm our preliminary data. DisclosuresNo relevant conflicts of interest to declare.

Poor Overall Survival in Hyperhaploid Multiple Myeloma Is Defined By Double-Hit Bi-Allelic Inactivation of TP53

Introduction Hyperhaploid multiple myeloma is a rare numerical aberration group defined by a range of 24-34 chromosomes. We have previously shown that hyperhaploid myeloma is associated with a poor prognosis with a 5-year survival rate of 23.1%, compared to 64% for hyperdiploid myeloma, and 80.4% for those with a normal karyotype. It is known that hyperhaploid myeloma frequently has monosomy of chromosome 17, making it a high risk group, but no data are currently available on the mutational status of this interesting sub-group, or how the copy number difference arises.Methods We analyzed data from whole genome, whole exome, and targeted panel sequencing from 1141 newly diagnosed myeloma patients. Internal samples were selected for whole exome or targeted sequencing based on previous karyotype information, or were identified in the process of other sequencing studies. The CoMMpass dataset was screened for the presence of hyperhaploidy. Hyperhaploid samples without prior karyotype information were identified by conflicting copy number profile and B allele frequency information, where the samples had incorrectly been normalized to a diploid copy number. These samples were re-normalized to a haploid copy number. Copy number, B allele frequency, and mutations of key genes were examined.Results In the entire dataset 9 hyperhaploid samples were identified, of which 2 came from the CoMMpass dataset. From those with gene expression array data, 5/7 were GEP70 high risk and all belonged to the D1 hyperdiploid gene expression subgroup. Samples had a median of 13 monosomies (range 9-14), which in general were those not associated with trisomies in hyperdiploid samples. The chromosomes traditionally trisomic in hyperdiploid myeloma were disomic in hyperhaploid myeloma. We examined the B allele frequency of these disomic chromosomes and saw that they all retained heterodisomy. Retention of heterodisomy indicates that the method of generating hyperhaploidy is through deletion of the monosomic chromosomes, rather than reverting to a haploid genome followed by duplication of some chromosomes. Retention of heterodisomy was also seen on chromosome 18, which is not normally trisomic in hyperdiploid samples, indicating that heterodisomy of chromosome 18 may be essential for a viable plasma cell clone.We examined the hyperhaploid samples for frequently mutated genes and found that 8/9 (88.8%) of hyperhaploid samples had a mutation in TP53. This rate of mutation far exceeds the overall rate of mutation in newly diagnosed patients (5.5%), indicating an oncogenic dependency in this group. The sample without mutation of TP53 had only 9 monosomies, fewer than the other samples (12-14 monosomies), indicating there may be a prognostic difference that is dependent on the total chromosome count. All samples with TP53 mutation also had monosomy of chromosome 17, indicating bi-allelic inactivation of TP53. The variant allele frequency of the TP53 mutations was high (median=0.94), indicating that bi-allelic inactivation was a clonal event. No other significant mutations were found, including those that encode chromosome segregation or kinetochore proteins.Conclusions We have previously described bi-allelic inactivation of TP53 as Double Hit myeloma, and here we identify that hyperhaploid myeloma belongs to this poor prognosis group. The method of generating the hyperhaploid clone is through deletion of chromosomes, which may happen in a way that is similar to gain of chromosomes in hyperdiploid myeloma. These Double Hit patients may be good candidates for new therapies, but using next generation sequencing techniques researchers must be careful when normalizing data to correctly identify them as hyperhaploid rather than hyperdiploid, using copy number and B allele frequency data. DisclosuresDavies:MMRF: Honoraria; TRM Oncology: Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; ASH: Honoraria. Morgan:Takeda: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Research Funding; Celgene: Consultancy, Honoraria, Research Funding.

Is mitochondrial DNA (MTDNA) quantification a potential biomarker for selection among euploid embryos?

Recently, there have been controversial publications about the clinical relevance of mtDNA quantification in human blastocysts. Previous studies have not found an association between this parameter and ploidy, maternal age or pregnancy outcome. However, some laboratories, based on their evidence, apply this quantification as an implantation potential biomarker between euploid embryos. Different methodologies have been used for mtDNA assessment, mainly next generation sequencing (NGS) platforms and real-time polymerase chain reaction (qPCR), with consistent results between them. The aim of this study was to evaluate if there was a relationship between human blastocyst mtDNA content and female age, embryo ploidy and clinical pregnancy. Retrospective cohort study. A cohort of 447 blastocysts obtained from 202 couples, with an average female age of 33.8 years old (21-46), undergoing preimplantation genetic testing for aneuploidies (PGT-A) were included. Data was collected between April 2016 and March 2018 from a single center. Mosaic embryos (between 20%-80%) were excluded from this analysis. Trophectoderm biopsies were assessed by NGS (Veriseq-Illumina). For each sample, reads were aligned to the human reference genome (hg19) and the mtDNA genome separately. The number of reads that mapped to the mtDNA were divided by the number of reads that mapped to the nuclear DNA in order to normalize technical variability. The resulting values were mathematically adjusted by correction factors for embryo ploidy (complete chromosomal monosomies or trisomies) and gender previously reported. T-test was performed for statistical analysis in order to analyze mtDNA scores regarding embryo aneuploidy, maternal age and clinical pregnancy. Regarding all blastocysts analyzed, 236 (53%) were euploid and 210 (47%) aneuploid. The amount of mtDNA was significantly higher in aneuploid embryos (P= 0.0002). However, the amount of mtDNA was not different between euploid embryos from younger (<38 years, n=187) and older women (≥38 years, n=49) (P=0.6870). During the period covered, 65 single embryo transfer were performed after thawing, resulting in 37 (57%) HCG-beta subunit positive and 26 (40%) ongoing pregnancies. The mtDNA score from euploid blastocysts that achieved a clinical pregnancy was no significantly different from those that did not result in an ongoing pregnancy (P=0.7589). This study contributes evidence that mtDNA quantification in euploid embryos have no clinical impact in pregnancy outcome. mtDNA score was only statistically associated with chromosomal aneuploidy suggesting that high levels of mtDNA may have a negative impact resulting in an inadequate chromosome segregation.

Prognostic significance of monosomal karyotype in myelodysplastic syndrome: a meta-analysis

ABSTRACTObjectives: In myelodysplastic syndrome (MDS), the prognostic role of monosomal karyotype (MK), defined as at least two autosomal monosomies or a single monosomy associated with at least one additional structural abnormality, remained controversial. Therefore, we conducted a meta-analysis to address this issue.Methods: PubMed, Embase, Web of Science, Medline, and the Cochrane Library were retrieved. We extracted hazard ratios (HRs) and the corresponding 95% confidential intervals (CIs) for overall survival (OS) on patients with MK versus those without, as well as on MK patients with monosomies of chromosome 7 and/or 5 versus those without from the available studies.Results: Seventeen studies covering 7500 patients were included this meta-analysis. The pooled HRs indicated MK had a negative impact on OS in MDS (pooled HR: 2.484, 95%CI: 2.033–3.036, P < .001), in MDS patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) (pooled HR: 2.150, 95%CI: 1.861–2.48, P < .001), and in MDS with complex karyotype (CK) (pooled HR: 2.56, 95%CI: 2.032–3.036, P = .01). However, monosomies of chromosome 5 and/or 7 had no impact on OS in MDS with MK (pooled HR: 1.330, 95%CI: 0.827–2.139, P = .240). Meta-regression indicated that therapy was the origin of the heterogeneity (P = .012).Discussion: Our meta-analysis indicated that MK has a negative impact on OS in MDS, in MDS patients undergoing allo-HSCT, and MDS with CK, but monosomies of chromosome 5 and/or 7 have no impact on OS in MDS with MK. The heterogeneity reflected the biologic and therapeutic heterogeneity of MDS.Conclusion: MK is associated with poor prognosis in MDS, the underlying mechanism needs further exploring.

Inheritance of Traits Controlled by Odd Chromosomes Using Data on Transmission of Monosomic Addition St Chromosome of the Elymus Sibiricus Genome

On the basis of the winter bread wheat cultivar Obryi, two independent disomic addition lines BC12F∞ with the chromosome of the E. sibiricus St genome are created. A practical algorithm for determining the probabilities of transmission of the odd chromosome separately through male and female gametes in selfpollination of hemizygous hybrids from the equation p2–(1 + f1–f4) × p + f1 = 0 is proposed, where p is the probability of the formation of viable gametes with the considered chromosome and f1 and f4 are the empirical frequencies of the corresponding homozygotes with and without the trait. The probability of transmission of an alien univalent chromosome through pollen (p♂) is associated with the frequency of its transmission through the egg cell (p♀) in backcrosses and in self-pollination (1–f4) by the equation p♂ = 1–f4/(1–p♀). The calculated empirically dependent estimates of the probabilities of transmission of the added chromosome through the egg cell p♀ = 18.7% and through pollen p♂ = 4.3% correspond to the empirical frequencies obtained for backcrosses. The coefficients of the gamete selection V♀ = 0.748 and V♂ = 0.172 are calculated, and the expected segregation for the alien trait controlled by a dominant gene located in the added chromosome is determined—with the trait: without the trait is 0.222: 0.778 in F2; 0.187: 0.813 in equational and 0.043: 0.957 in certational backcrosses.

35. Runs of homozygosity (ROH) reveal that segmental-UPD is associated with the repair of genomic imbalance

Uniparental disomy (UPD) in the context of whole chromosome non-disjunction mediated trisomy or monosomy is well documented with mechanisms largely understood. In contrast, the etiology of segmental UPD (segUPD) existing in only a portion of a chromosome pair, primarily evinced by a terminal absence of heterozygosity, occurs rarely and the etiology is not well documented. In the course of confirming (300) cases of whole chromosome UPD using single nucleotide polymorphism (SNP) microarrays to detect runs of homozygosity (ROH) associated with UPD we identified 62 cases of segUPD in prenatal and postnatal samples. Nearly half of these cases were due to positive selection based Beckwith-Wiedemann syndrome 11p15 imprinting imbalance. We highlight a subset of the remaining cases to show that segUPD occurs secondarily to mitotic recombination based correction of genomic imbalances that include deletions, translocation derivative chromosomes and terminal deletions with contiguous duplications. Non-invasive prenatal testing (NIPT), CVS, placental, amniotic fluid and peripheral blood samples taken from several individuals at multiple times show temporal correction of aberrations during fetal development. Although the various genetic lesions are “repaired”, sustained clinical effects might still be present because the original imbalance may have affected early development, may still be present in some cells or the resulting seg-UPD may unmask a recessive disorder. In the case of genomic rearrangements consisting of terminal deletions with contiguous duplications, we hypothesize that genomic repair processes restore euploidy if initiated proximal to the duplication, but result in a triplication and terminal segUPD if initiated at the “end” of the inverted duplication. Importantly, these studies suggest that the incidence of segUPD mediated correction is underestimated, and may explain the etiology of clinical phenotypes that are undetected by CGH based microarray analysis and whole exome sequencing studies.

Chromosome-wide gene dosage rebalance may benefit tumor progression.

The high-risk of tumor initiation in patients with Turner syndrome (TS) characterized by X chromosome monosomy in women has been well established and aneuploidy, defined as an abnormal number of chromosomes, is a common feature in human cancer. However, the underlying mechanisms of X chromosome aneuploidy promoting tumorigenesis remain obscure. We propose that chromosome-wide gene dosage imbalance (CDI) may serve as an important mechanism. Here, we assess the relative expression ratios of X chromosome and autosomes (expression ratios of X:AA) between tumor samples and adjacent normal samples across 16 tumor types using expression datasets from The Cancer Genome Atlas (TCGA) project. Our results show that the expression ratios of X:AA in tumor samples are frequently rebalanced to a lower level compared to those in adjacent normal samples, which is termed chromosome-wide gene dosage rebalance (CDR) thereafter. Gene ontology (GO) analysis of differentially expression genes from X chromosome reveals that downregulation of multicellularity-related genes and upregulation of unicellularity-related genes in tumors form a distinctive feature and enrichment analysis shows that downregulated genes are enriched in tumor suppressor genes, which indicate that CDR benefits tumor progression. Further experimental results prove that disturbance of X chromosome expression by knocking down of XIST in breast cancer cells, which functions in initiation phase of X chromosome inactivation (XCI), inhibits tumor progression. Our results demonstrate that the prevalent CDRs across tumor types serve as an important mechanism in promoting tumor progression, which partially explains the high risk of tumor in patients with TS and also provides a new cancer therapy from the CDR perspective.

Transcriptional Regulation on Aneuploid Chromosomes in Diverse Candida albicans Mutants

Candida albicans is a diploid fungus and a predominant opportunistic human pathogen. Notably, C. albicans employs reversible chromosomal aneuploidies as a means of survival in adverse environments. We previously characterized transcription on the monosomic chromosome 5 (Ch5) that arises with adaptation to growth on the toxic sugar sorbose in the mutant Sor125(55). We now extend this analysis to the trisomic hybrid Ch4/7 within Sor125(55) and a diverse group of three mutants harboring a single Ch5. We find a similar pattern of transcriptional changes on either type of aneuploid chromosome within these mutants wherein expression of many genes follows chromosome ploidy, consistent with a direct mechanism to regulate genes important for adaptation to growth. In contrast, a significant number of genes are expressed at the disomic level, implying distinct mechanisms compensating for gene dose on monosomic or trisomic chromosomes consistent with maintaining cell homeostasis. Finally, we find evidence for an additional mechanism that elevates expression of genes on normal disomic Ch4 and Ch7 in mutants to levels commensurate with that found on the trisomic Ch4/7b in Sor125(55). Several of these genes are similarly differentially regulated among mutants, suggesting they play key functions in either maintaining aneuploidy or adaptation to growth conditions.

Analysis of Chromosome 3, 7 and 8 Centromeric Regions in Bronchial Lavage Specimens by FISH.

Multiple genetic changes are observed in malignant tumors but are rare or absent in benign conditions. Aneuploidy is the most common feature of solid tumors including lung cancer and diagnosis of malignant tumors is possible through detection of aneuploidy. The aim of this study was to investigate chromosomal abnormalities in cells from non-small cell lung cancer patients obtained bronchoscopically and to evaluate the suitability of fluorescence in situ hybridization (FISH). Bronchial lavage samples of 17 non-small cell lung cancer (NSCLC) patients were evaluated with four-color FISH using deoxyribonucleic acid (DNA) probes specific for the centromere regions of chromosomes 3, 7 and 8. tested specimens were first hybridized with probes, then visualized under fluorescence microscobe and captured with device's camera. High number of aneuploidic cells were detected in all the samples. Increased or decreased abnormal copies or chromosomes 3, 7 and 8 were obserced in all the 17 patients. Aneuploidy of chromosome 3 (21.35%) was higher than those of chromosome 7 (9.06%) and chromosome 8 (15.47%). Moreover, our results were significant for monosomy and trisomy of chromosome 3, trisomy of chromosome 7, nullisomy, monosomy and trisomy of, chromosome 8 (p< 0.05). It has been observed that FISH is a useful technique for detection of aneuploidy in bronchial lavage samples obtained by bronchoscopy. Interphase cells were evaluated without cell culturing with this method and high number of tumor cells were enumerated rapidly. Our study has demonstrated that, FISH technique may be used successfully in detection of chromosome number abnormalities in NSCLC patients and may facilitate evaluation of genetic abnormalities.

Coexistence of deletion, ring, and monosomy of chromosome 7 in a patient with MDS-RAEB-2

Coexistence of deletion, ring, and monosomy of chromosome 7 in a patient with MDS-RAEB-2

Should embryos with autosomal monosomy by preimplantation genetic testing for aneuploidy be transferred?: Implications for embryo selection from a systematic literature review of autosomal monosomy survivors.

To review the literature for survival and phenotypes of liveborns with autosomal monosomy to inform decisions regarding transfer of in vitro fertilization-derived embryos reported as monosomic on preimplantation genetic testing for aneuploidy (PGT-A). Ovid-Medline and EMBASE were systematically searched to identify published case reports of liveborn individuals with autosomal monosomy, full or mosaic, for a whole chromosome. Fifty-three reports describing 56 individuals with autosomal monosomy met the selection criteria: 1 case each of monosomy 14 and 16, 3 each for monosomy 15 and 18, 1 for group "E", 5 for monosomy 20, 24 for monosomy 21, 7 for monosomy 22, and eleven for a "G" group chromosome. There were no reports with monosomy for the larger chromosomes 1 through 13, nor for chromosomes 17 or 19, autosomes with highest gene density. Most reported individuals had severe handicaps and died in infancy with some surviving longer. Given potential for survival of handicapped individuals with autosomal monosomy for chromosomes 14, 15, 16, 18, 20, 21, and 22, low priority should be given to transfer of embryos apparently monosomic for these chromosomes. Couples electing transfer of monosomic embryos should consider amniocentesis for ongoing pregnancies but should be informed of its limitations.