Chromosomal Aberrations Research Articles

Scaled and efficient derivation of loss-of-function alleles in risk genes for neurodevelopmental and psychiatric disorders in human iPSCs

Translating genetic findings for neurodevelopmental and psychiatric disorders (NPDs) into actionable disease biology would benefit from large-scale and unbiased functional studies of NPD genes. Leveraging the cytosine base editing (CBE) system, we developed a pipeline for clonal loss-of-function (LoF) allele mutagenesis in human induced pluripotent stem cells (hiPSCs) by introducing premature stop codons (iSTOP) that lead to mRNA nonsense-mediated decay (NMD) or protein truncation. We tested the pipeline for 23 NPD genes on 3 hiPSC lines and achieved highly reproducible, efficient iSTOP editing in 22 genes. Using RNA sequencing (RNA-seq), we confirmed their pluripotency, absence of chromosomal abnormalities, and NMD. Despite high editing efficiency, three schizophrenia risk genes (SETD1A, TRIO, and CUL1) only had heterozygous LoF alleles, suggesting their essential roles for cell growth. We found that CUL1-LoF reduced neurite branches and synaptic puncta density. This iSTOP pipeline enables a scaled and efficient LoF mutagenesis of NPD genes, yielding an invaluable shareable resource.

LINE-1 methylation index correlates with sister chromatid exchanges and chromatid but not chromosome aberrations in personnel from a nuclear chemical facility with incorporated plutonium-239

LINE-1 methylation index correlates with sister chromatid exchanges and chromatid but not chromosome aberrations in personnel from a nuclear chemical facility with incorporated plutonium-239

Whole genome analysis of Salmonella Gallinarum strains isolated from a fowl typhoid outbreak in southern Brazil

ABSTRACT 1. Salmonella Gallinarum strains isolated from a southern Brazil fowl typhoid outbreak were subjected to phenotypic and genotypic analyses to identify genetic elements that could improve prevention and control strategies. 2. Whole-genome sequencing revealed the presence of the aac(6’)-Iaa gene, conferring aminoglycoside resistance, along with novel chromosomal point mutations, including the first detection of parE p.S451F in Salmonella Gallinarum. 3. Additionally, IncFII(S) plasmid replicons, Salmonella pathogenicity islands and 105 virulence genes associated with cell adhesion, invasion and antimicrobial peptide resistance were identified. 4. These findings shed light on the molecular mechanisms of fowl typhoid and provide crucial insights into emerging antimicrobial resistance and virulence factors.

Association of ADAM family members with proliferation signaling and disease progression in multiple myeloma

Multiple myeloma (MM) is a hematological malignancy whose curability is greatly challenged by recurrent patient relapses and therapy resistance. We have previously proposed the high expression of ADAM8, ADAM9 and ADAM15 (A Disintegrin And Metalloproteinase 8/9/15) as adverse prognostic markers in MM. This study focused on the so far scarcely researched role of ADAM8/9/15 in MM using two patient cohorts and seven human MM cell lines (HMCL). High ADAM8/9/15 expression was associated with high-risk cytogenetic abnormalities and extramedullary disease. Furthermore, ADAM8/15 expression increased with MM progression and in relapsed/refractory MM compared to untreated patient samples. RNA sequencing and gene set enrichment analysis comparing ADAM8/9/15high/low patient samples revealed an upregulation of proliferation markers and proliferation-associated gene sets in ADAM8/9/15high patient samples. High ADAM8/9/15 expression correlated with high Ki67 and high ADAM8/15 expression with high MYC protein expression in immunohistochemical stainings of patient tissue. Conversely, siRNA-mediated knockdown of ADAM8/9/15 in HMCL downregulated proliferation-related gene sets. Western blotting revealed that ADAM8 knockdown regulated IGF1R/AKT signaling and ADAM9 knockdown decreased mTOR activation. Lastly, high ADAM8/9/15 expression levels were verified as prognostic markers independent of Ki67/MYC expression and/or high-risk abnormalities. Overall, these findings suggest that ADAM8/9/15 play a role in MM progression and proliferation signaling.

Catatonia Optimized With ECT and Maintenance IV Lorazepam in a Rare Chromosomal Disorder.

Catatonia Optimized With ECT and Maintenance IV Lorazepam in a Rare Chromosomal Disorder.

Molecular Profiling Defines Three Subtypes of Synovial Sarcoma.

Synovial Sarcomas (SS) are characterized by the presence of the SS18::SSX fusion gene, which protein product induce chromatin changes through remodeling of the BAF complex. To elucidate the genomic events that drive phenotypic diversity in SS, we performed RNA and targeted DNA sequencing on 91 tumors from 55 patients. Our results were verified by proteomic analysis, public gene expression cohorts and single-cell RNA sequencing. Transcriptome profiling identified three distinct SS subtypes resembling the known histological subtypes: SS subtype I and was characterized by hyperproliferation, evasion of immune detection and a poor prognosis. SS subtype II and was dominated by a vascular-stromal component and had a significantly better outcome. SS Subtype III was characterized by biphasic differentiation, increased genomic complexity and immune suppression mediated by checkpoint inhibition, and poor prognosis despite good responses to neoadjuvant therapy. Chromosomal abnormalities were an independent significant risk factor for metastasis. KRT8 was identified as a key component for epithelial differentiation in biphasic tumors, potentially controlled by OVOL1 regulation. Our findings explain the histological grounds for SS classification and indicate that a significantly larger proportion of patients have high risk tumors (corresponding to SS subtype I) than previously believed.

Physical activity and indices of physical well-being in children and adolescents with trisomy 21

Introduction: Trisomy 21 (Down syndrome) is the most common genetic disorder, which is caused by a chromosomal abnormality and presents various deviations in areas such as mental and motor levels. The presence of extra information corresponding in whole or in part to chromosome 21 affects the development of children with trisomy 21, and abnormal gene expression leads to changes in brain function. The overall prevalence of the syndrome is one (1) to two (2) per thousand (1,000) live births, although the prevalence may have variability among racial or ethnic groups. The purpose of this research is to highlight the deviations in the balance ability, the strength of the upper limbs, and to what extent they affect the quality of life of children and adolescents with trisomy 21. Methods: Eighteen (18) children and adolescents with trisomy 21 participated in the research, with three (3) being excluded due to exclusion criteria. Fifteen (15) children and adolescents with trisomy 21 were finally included, of which four (4) were boys and eleven (11) were girls.

Genomic Balancing Act: deciphering DNA rearrangements in the complex chromosomal aberration involving 5p15.2, 2q31.1, and 18q21.32.

Despite extensive research into the genetic underpinnings of neurodevelopmental disorders (NDD), many clinical cases remain unresolved. We studied a female proband with a NDD, mildly dysmorphic facial features, and brain stem hypoplasia on neuroimaging. Comprehensive genomic analyses revealed a terminal 5p loss and aterminal 18q gain in the proband while a diploid copy number for chromosomes 5 and 18 in both parents. Genomic investigations in the proband identified an unbalanced translocation t(5;18) with additional genetic material from chromosome 2 (2q31.3) inserted at the breakpoint, pointing to a complex chromosomal rearrangement (CCR) involving 5p15.2, 2q31.3, and 18q21.32. Breakpoint junction analyses enabled by long-read genome sequencing unveiled the presence of four distinct junctions in the father, who is acarrier of a balanced CCR. The proband inherited from the father both the abnormal chromosome 5 resulting in segmental aneusomies of chr5 (loss) and chr18 (gain) and a der(2) homologue. Evidences suggest a chromoplexy mechanism for this CCR derivation, involving double-strand breaks (DSBs) repaired by non-homologous end joining (NHEJ) or alternative end joining (alt-EJ). The complexity of the CCR and the segregation of homologues elucidate the genetic model for this family. This study demonstrates the importance of combining multiple genomic technologies to uncover genetic causes of complex neurodevelopmental syndromes and to better understand genetic disease mechanisms.

Discovering down's syndrome: An account from A low middle income country.

This study aims to establish the frequency of Down's syndrome which will enhance the knowledge of our local population as well to understand our genotypic patterns and variations. Electronic Medical Records of inborn babies at the Department of Neonatology, Sheikh Saeed Memorial Campus of The Indus Hospital Karachi during the study period from 1st January 2021 to 31st December 2022 were retrieved. Chromosomal karyotyping was done for all babies with suspicious clinical features identified on routine new born examination by consultant neonatologists, trainee doctors and experienced nurses. There was a total of 7,433 live births during the study period, out of which 14 babies had features suggestive of DS. repetition of sentence. What about karyotyping result?? The frequency of DS in our study is slightly higher than the incidence reported within South East Asia. It is high time to perform effective antenatal screening and efficient prenatal diagnostic services for early detection of chromosomal numerical aberration such as Down syndrome for better management of upcoming pregnancies.

Complete morphologic response to gilteritinib in ALK-rearranged acute myeloid leukemia

The cytogenetic abnormality inv(2)(p23q13) in acute myeloid leukemia (AML) results in a fusion of RANBP2 with ALK. This fusion makes ALK constitutively active and acts as a driver for the proliferation of AML cell lines. Gilteritinib, a FLT3 inhibitor approved in AML, also can inhibit ALK among other receptor tyrosine kinases. A 75-year-old-woman with a history of essential thrombocythemia (ET) and a presumed germline DDX41 mutation developed ALK-fusion positive AML and despite standard therapies was transfusion-dependent and globally declining. The patient has been on gilteritinib with an ongoing response of more than one year with near normal blood counts and no evidence of AML. The fact that she was found to harbor a presumed germline DDX41 alteration may account for why she developed, and yet survived, two myeloid neoplasms (ET and AML). Additionally, this demonstrates that gilteritinib is clinically active as an ALK inhibitor, and could be considered for use in any AML patient presenting with an inv(2(p23q13)) translocation. Finally, it is an example of using a disease-agnostic, precision medicine approach to arrive at a beneficial treatment.

Causes of Hospitalization in Children with Down Syndrome.

Background and Objectives: Down syndrome (DS) is the most common chromosomal disorder in the world. It is caused by the imbalance of the chromosomal constitution of 21 by free trisomy, translocation or mosaicism. Children and adolescents with Down syndrome have immune dysregulation and are more susceptible to infections. This study aims to evaluate hospitalizations of children and adolescents with DS in the pediatric ward of Botucatu Clinics Hospital (HCFMB) and to classify the population of children included in the study according to age, diagnosis, outpatient follow-up, length of stay and need for the intensive care unit (ICU). Thus, it will be possible to improve care for these children, aiming to reduce these hospitalizations. Materials and Methods: This study was an observational, cross-sectional study, with retrospective data collected from the last nine years of hospitalization, from January 2013 to December 2021, from children and adolescents with DS in the pediatric ward, emergency room, and the ICU of HCFMB. Children hospitalized in this period in the pediatric ward and ICU, in the age range of 30 days to 15 years, were included in this study. The evaluation of comorbidities that culminated in the need for hospitalization in this population can be the focus of actions to improve the diagnoses and conducts for this population, which can prevent worsening illness and hospitalizations in future populations. Results: In this analysis, 80 children with DS were evaluated, with a total of 283 hospitalizations. The most prevalent age group was 1 to 3 years, and the main cause was due to problems in the respiratory system (99 cases). Among the respiratory causes, the main cause of hospitalization was due to pneumonia in 50% of cases, followed by acute respiratory failure in 14%. The average hospitalization time was 8 days, and in 49 hospitalizations, the children required the ICU. The main cause of hospitalization in the ICU was due to respiratory causes (36%), followed by cardiac malformations (14%). During the ICU hospitalizations, there were 13 deaths, and we observed a higher prevalence of heart conditions and, in some cases, positive urine cultures in these children. Conclusions: The Hospital serves as a reference for pediatric hospitalizations within its region and beyond, owing to its specialized capabilities. The main causes of hospitalization were those related to the respiratory system and cardiac malformations. Roughly one-third of the children required admission to the intensive care unit.

Fetal Cystic Lymphatic Malformations: Systematic Review on Pregnancy and Neonatal Outcomes.

Evaluate pregnancy and neonatal outcomes with fetal cystic lymphatic malformations (LMs), excluding those arising from the posterior neck, to facilitate patient counseling. A systematic review was performed in accordance with PRISMA guidance. Case series and case reports published between 2000 and 2022 were included. Sixty-five studies (96 fetuses) met the inclusion criteria. The average gestational age at diagnosis was 25.5 weeks with the commonest location being the anterior neck (28%). All patients were diagnosed with LM using two-dimensional (2D) ultrasound. Prenatal progression in LM size, presence of intralesional bleeding, or fetal hydrops occurred in 70% (41/59), 9% (5/59), and 3% (2/59), respectively. Chromosomal and structural abnormalities were reported in 4% (2/52) and 2% (2/96), respectively. Overall livebirth rate was 94% (79/84); 12/96 resulted in termination and 5/84 in in utero demise. The average gestational age of delivery was 37.7 weeks. Exactly 19% (15/79) had a vaginal birth, of which shoulder dystocia occurred in one infant. Ex utero intrapartum treatment (EXIT) procedure was performed in 13% (10/79). Postnatal treatment commonly involved surgical excision 38% (30/79), sclerotherapy in 21.5% (17/79), or combination of both in 11.4% (9/79). Of those with reported follow-up, 4 died within 1 year, 1 developed heart failure at 2 years of life, and the remaining 44 had normal developmental outcomes. Fetal cystic LMs, excluding those in the posterior neck, are not commonly associated with chromosomal, or additional structural abnormalities. They usually increase in size before delivery with only a minority developing complications. The good developmental outcome was reported in all survivors.

Bifidobacterium longum subsp. infantis YLGB-1496-Toxicological evaluation.

Bifidobacterium infantis YLGB-1496, originally isolated from breast milk from a Taiwanese mother, is under study for use as a probiotic. As part of safety assessment, an Ames, in vivo mouse micronucleus, and in vivo mouse spermatocyte chromosome aberration assay were conducted along with a 13-week oral rat toxicity study. B.infantis YLGB-1496 had no activity in any of the genotoxicity assays. Administration of the bacteria to Sprague-Dawley rats at doses ranging from 0 to 1.5 g/kg bw/day had no treatment-related effects on any of the endpoints measured. There appear to be no concerns for translocation or pathogenicity of B.infantis YLGB-1496 based on extensive experience with the species in general. The results of the current investigations support potential use of B.infantis YLGB-1496 as a probiotic in infant formula.

Bortezomib, lenalidomide, and dexamethasone versus bortezomib, doxorubicin, and dexamethasone in newly diagnosed multiple myeloma

Bortezomib, lenalidomide, and dexamethasone (VRD), and bortezomib, doxorubicin, and dexamethasone (PAD), are commonly used in induction regimens for patients with newly diagnosed multiple myeloma (NDMM) in China. This real-world study enrolled 390 patients, 195 receiving VRD and 195 receiving PAD induction. The primary endpoint was progression-free survival (PFS) and stringent complete remission/complete remission. Across the entire cohort, VRD demonstrated significantly improved five-year overall survival (OS) (74% vs. 59%, p = 0.0024) and five-year PFS (67% vs. 37%, p = 0.0018) compared to PAD. Notably, the median OS and PFS were not reached for VRD-treated patients, while they were 77 months (60-not reached [NR]) and 46 months (36-NR), respectively, for PAD. In patients with standard-risk cytogenetics, VRD showed superior five-year OS (83% vs. 58%, p = 0.0038) and PFS (78% vs. 48%, p = 0.0091) compared to PAD. However, these differences were not statistically significant in high-risk patients. For transplanted patients, VRD was associated with superior five-year OS (91% vs. 67%, p = 0.014) and PFS (79% vs. 47%, p = 0.015) compared to PAD. In non-transplanted patients, VRD showed a trend towards improved five-year OS (p = 0.085) and PFS (p = 0.073) compared to the PAD group. In conclusion, VRD displayed superior OS and PFS outcomes in standard-risk patients and those who underwent transplantation. These findings suggest potential advantages of VRD over PAD in real-world clinical settings for NDMM treatment. However, due to the imbalance in transplantation rates between the VRD and PAD groups, limitations in testing for high-risk cytogenetic abnormalities (HRA), and the difference between the received cycles and salvage therapies, the conclusions of this study should be interpreted with caution.

Characterization of driver mutations identifies gene signatures predictive of prognosis and treatment sensitivity in multiple myeloma.

In multiple myeloma (MM), while frequent mutations in driver genes are crucial for disease progression, they traditionally offer limited insights into patient prognosis. This study aims to enhance prognostic understanding in MM by analyzing pathway dysregulations in key cancer driver genes, thereby identifying actionable gene signatures. We conducted a detailed quantification of mutations and pathway dysregulations in 10 frequently mutated cancer driver genes in MM to characterize their comprehensive mutational impacts on the whole transcriptome. This was followed by a systematic survival analysis to identify significant gene signatures with enhanced prognostic value. Our systematic analysis highlighted 2 significant signatures, TP53 and LRP1B, which notably outperformed mere mutation status in prognostic predictions. These gene signatures remained prognostically valuable even when accounting for clinical factors, including cytogenetic abnormalities, the International Staging System (ISS), and its revised version (R-ISS). The LRP1B signature effectively distinguished high-risk patients within low/intermediate-risk categories and correlated with significant changes in the tumor immune microenvironment. Additionally, the LRP1B signature showed a strong association with proteasome inhibitor pathways, notably predicting patient responses to bortezomib and the progression from monoclonal gammopathy of unknown significance to MM. Through a rigorous analysis, this study underscores the potential of specific gene signatures in revolutionizing the prognostic landscape of MM, providing novel clinical insights that could influence future translational oncology research.

Chromosome aberrations cause tumorigenesis through chromosomal rearrangements in a hepatocarcinogenesis rat model.

Chromosome aberrations (CAs), a genotoxic potential of carcinogens, are believed to contribute to tumorigenesis by chromosomal rearrangements through micronucleus formation. However, there is no direct evidence that proves the involvement of CAs in tumorigenesis invivo. In the current study, we sought to clarify the involvement of CAs in chemical carcinogenesis using a rat model with a pure CA-inducer hepatocarcinogen, acetamide. Whole-genome analysis indicated that hepatic tumors induced by acetamide treatment for 26-30 weeks showed a broad range of copy number alterations in various chromosomes. In contrast, hepatic tumors induced by a typical mutagen (diethylnitrosamine) followed by a nonmutagen (phenobarbital) did not show such mutational patterns. Additionally, structural alterations such as translocations were observed more frequently in the acetamide-induced tumors. Moreover, most of the acetamide-induced tumors expressed c-Myc and/or MDM2 protein due to the copy number gain of each oncogene. These results suggest the occurrence of chromosomal rearrangements and subsequent oncogene amplification in the acetamide-induced tumors. Taken together, the results indicate that CAs are directly involved in tumorigenesis through chromosomal rearrangements in an acetamide-induced hepatocarcinogenesis rat model.

Cellular toxicity of calcium propionate in human lymphocyte.

Calcium propionate is the chemical substance added to food in order to prolong the shelf-life of factory made foods by inhibiting the development of bacteria, fungi and other microorganisms. The objective of this study was to investigate the ability of calcium propionate to induce cytotoxic and genotoxic effects in lymphocytes. Oxidative stress induction by calcium propionate was also studied. Four concentrations of calcium propionate (0.5, 1.0, 1.5 and 2.0 mg/ml) were applied in lymphocytes for 24 and 48 h treatment. It studied cytotoxic and genotoxic effects by MTT assay, chromosome culture technique, and micronucleus assay. Oxidative stress induction was studied by superoxide dismutase (SOD) activity assay. The results showed that lymphocyte viability was decreased significantly by calcium propionate at 1.5 and 2.0 mg/ml (p < 0.05). Calcium propionate induced chromosome aberration at 1.0, 1.5 and 2.0 mg/ml and sister chromatid exchange at 1.5 and 2.0 mg/ml (p < 0.05). It induced micronucleus formation at 0.5, 1.0, 1.5 and 2.0 mg/ml (p < 0.05). The calcium propionate concentrations of 0.5 - 1.0 mg/ml and 1.5 - 2.0 mg/ml could reduce SOD activity inhibition (p < 0.05). Calcium propionate induced oxidative stress in lymphocytes. It can be concluded that calcium propionate induces genotoxic risk and oxidative stress in lymphocytes. Based on this study and the positive results, consumers should be made aware that calcium propionate should be considered a genotoxic compound. The awareness of food preservative usage and the educational program must take place frequently for good human health in the community.

Pregnancies with ‘double-positive’ multiple marker screening results: a population-based study in Ontario, Canada

BackgroundMultiple marker screening is offered to pregnant individuals in many jurisdictions to screen for trisomies 21 and 18. On occasion, the result is ‘double-positive’—a screening result that is unexpectedly positive for both aneuploidies. Although this occurs rarely, the paucity of available evidence about the outcomes of these pregnancies hinders patient counselling. This study aimed to investigate the association of double-positive results with preterm birth and other adverse perinatal outcomes.MethodsWe conducted a population-based retrospective cohort study of pregnancies with an estimated date of delivery from September 1, 2016, to March 31, 2021, using province-wide perinatal registry data in Ontario, Canada. Pregnancies with double-positive screening results where trisomies 21 and 18 were ruled-out were compared to pregnancies with screen negative results for both aneuploidies. We used modified Poisson regression models with robust variance estimation to examine the association of double positive results with preterm birth and secondary outcomes.ResultsFrom 429 540 pregnancies with multiple marker screening, 863 (0.2%) had a double-positive result; trisomies 21 and 18 were ruled out in 374 pregnancies, 203 of which resulted in a live birth. Among the pregnancies in the double-positive group resulting in a live birth, the risk of preterm birth was increased compared to pregnancies with a screen negative result: adjusted risk ratio (aRR) 2.6 (95%CI 2.0-3.6), adjusted risk difference (aRD) 10.5% (95%CI 5.4–15.7). In a sensitivity analysis excluding all diagnosed chromosomal abnormalities, the risk of preterm birth remained elevated to a similar degree: aRR 2.6 (95%CI 1.9–3.7), aRD 10.0% (95%CI 4.8–15.3). The risk of other adverse perinatal outcomes was also higher, including the risk of chromosomal abnormalities other than trisomies 21 and 18: aRR 81.1 (95%CI 69.4–94.8), aRD 34.0% (95%CI 29.2–38.8). Pregnancies with double-positive results were also less likely to result in a live birth, even when excluding all diagnosed chromosomal abnormalities; and at increased risk of adverse perinatal outcomes for those resulting in a live birth.ConclusionAlthough rare, double-positive multiple marker screening results are associated with an increased risk of preterm birth and other adverse perinatal outcomes, even when excluding all identified chromosomal abnormalities.

Long-term survival after unrelated donor marrow transplantation for aplastic anaemia after optimized conditioning regimen: a retrospective multicentre cohort study

Almost all acquired severe aplastic anaemia is immune mediated and characterised by hypocellular bone marrow and ≥2 affected haematopoietic lineages. The optimal preparartive regimen for unrelated donor transplantation remains to be established. We aimed to study long-term outcomes after unrelated donor transplantation for severe aplastic anaemia with de-escalation of cyclophosphamide (Cy) dose in steps of 50mg/kg (150, 100, 50, 0mg/kg) in combination with total body irradiation (TBI) 2Gy, anti-thymocyte globulin (ATG) and fludarabine. Ninety-six patients with severe aplastic anaemia aged ≤65 years with adequate organ function enrolled on a trial of human leukocyte antigen (HLA)-matched or 1 HLA-locus mismatched unrelated donor marrow transplantation conducted between 02/2006 and 12/2013 in the United States (NCT00326417). Exclusion criteria were Karnofsky performance status of less than 60, clonal cytogenetic abnormalities and inherited marrow failure syndormes. The primary outcome was day-100 engraftment (achievement of absolute neutrophil recovery to at least 0.5×109/L without subsequent decline) and day-100 survival. The trial determined the lowest effective Cydose as 50mg/kg (n=38) for day-100 engraftment and survival. Cy dose 100mg/kg (n=41) was also acceptable. Accrual to Cy doses 150mg/kg (n=15) and 0mg/kg (n=3) was terminated early for toxicities. The current study is an extended follow up of patients enrolled on the trial (NCT00326477) and includes 76 of 96 patients alive ≥1 year after transplantation. There were 20 deaths in the first year after transplantation (Cy 0mg/kg [n=2], Cy 50mg/kg [n=1], Cy 100mg/kg [n=10], Cy 150mg/kg [n=7]). Patients were followed prospectively from transplantation and data reported using standardized data collection forms until death, loss to follow up or last contact through November 2023. The incidence of graft failure was calculated using the cumulative incidence estimator and the probability of survival using the Kaplan-Meier estimator. The median follow up of the cohort is 8.02 (IQR) 5.16-10.12) years. With Cy 50mg/kg, there was one graft failure and five deaths ≥1 year after transplantation. With Cy 100mg/kg there was only one late death and no graft failure. The 8-year probabilities of survival were 85.0% (95% CI 67.3-93.5) and 75.6% (95% CI 59.4-86.1) after Cy50mg/kg and 100mg/kg, respectively, P=0.31. With Cy 0mg/kg and 150mg/kg, there were no graft failures or death ≥1 year after transplantation. Regardless of Cy dose 12 of 15 patients aged ≥50 years died. Cy 50mg/kg or 100mg/kg with TBI 2Gy, ATG and fludarabine are effective conditioning regimens for unrelated donor marrow transplants for aplastic anaemia. Identification of an optimized transplantation approach for patients aged ≥50 years is needed. US National Institutes of Health.

Combined first-trimester screening and invasive diagnostics for atypical chromosomal aberrations: Danish nationwide study of prenatal profiles and detection compared with NIPT.

Our aim was to examine the prenatal profiles of pregnancies affected by an atypical chromosomal aberration, focusing on pathogenic copy-number variants (pCNVs). We also wanted to quantify the performance of combined first-trimester screening (cFTS) and a second-trimester anomaly scan in detecting these aberrations. Finally, we aimed to estimate the consequences of a policy of using non-invasive prenatal testing (NIPT) rather than invasive testing with chromosomal microarray analysis (CMA) to manage pregnancies identified as high risk by cFTS. This was a retrospective review of the Danish Fetal Medicine Database of all pregnant women who underwent cFTS and a risk assessment for trisomy 21 between 1 January 2008 and 31 December 2018. Chromosomal aberrations diagnosed prenatally, postnatally or from fetal tissue following pregnancy loss or termination of pregnancy were identified. Chromosomal aberrations were grouped into one of six categories: triploidy; common trisomy (13, 18 or 21); monosomy X; other sex-chromosome aberration (SCA); pCNV; and rare autosomal trisomy (RAT) or mosaicism. The prevalence of each aberration category was stratified by the individual cFTS markers and trisomy 21 risk estimate, and the size of each pCNV diagnosed by CMA was calculated. We retrieved data on 565 708 pregnancies, of which 3982 (0.70%) were diagnosed with a fetal chromosomal aberration. cFTS identified 87% of the common trisomies, but it also performed well in identifying triploidies (86%), monosomy X (92%), atypical SCAs (58%) and RATs or mosaicisms (70%). pCNVs comprised 27% (n = 1091) of the chromosomal aberrations diagnosed overall, and the prevalence increased during the study period, as prenatal CMA was increasingly being performed. In pregnancies with a maternal age < 30 years, nuchal translucency (NT) thickness ≤ 95th centile, pregnancy-associated plasma protein-A (PAPP-A) ≥ 1 multiple of the median, or trisomy 21 risk of ≤ 1 in 1000, the prevalence of pCNVs exceeded significantly the prevalence of trisomies 21, 18 and 13. Pregnancies affected by a pCNV had significantly increased NT and decreased levels of the maternal biomarkers PAPP-A and β-human chorionic gonadotropin compared with unaffected pregnancies. However, only 23% of these pregnancies screened positive on cFTS and 51% of pCNVs were not detected until after birth. Among high-risk pregnancies, pCNVs comprised 14% of diagnosed aberrations, and when other atypical aberrations were considered, conventional NIPT (screening for trisomies 21, 18 and 13 and monosomy X) would miss 27% of all pathogenic aberrations diagnosed from invasive testing following a high-risk cFTS result. Thus, 1 in 26 pregnancies at high risk following cFTS would be affected by a chromosomal aberration despite a normal result from conventional NIPT. In a contingent screening model using NIPT for the 'intermediate'-risk group (trisomy 21 risk of 1 in 100-299), 50% of the aberrations would be missed. In our cohort, 79% of the pCNVs diagnosed were < 5Mb and therefore not detectable using current forms of 'genome-wide' NIPT. As a by-product of screening for trisomies 21, 18 and 13, most triploidies and the majority of atypical SCAs, RATs and mosaicisms are detected before birth. However, only 23% of pCNVs are associated with a high-risk result according to cFTS and only half are diagnosed before birth. Replacing invasive testing with NIPT for high-risk pregnancies would substantially decrease the first-trimester detection of pathogenic chromosomal anomalies. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.