Chromosome Aneuploidy Research Articles

Comparison of web-based information about cell-free DNA prenatal screening: implications for differences of sex development care

ObjectiveCell-free DNA (cfDNA) prenatal screening is a commercially available noninvasive test that detects fetal genetic material in maternal blood. While expectant parents often use it for “gender” determination, there is little information about unintended consequences of testing, such as revelation of a difference of sex development (DSD). The study aimed to characterize currently available website information about cfDNA and compare the cfDNA-related content.MethodsA systematic search for websites with information about cfDNA was conducted using search terms generated by a natural language processing analysis of the results of an Amazon Mechanical Turk (MTurk) survey of 1,000 parents and then performing a “Google” search, using the terms. Commercial cfDNA testing companies (CC) websites were also identified by consulting a genetic counselor (AGW). Data were collected on about each website’s characteristics and information about cfDNA. Information about cfDNA was compared between websites. Data were analyzed using descriptive statistics, Fisher’s exact test or Kruskal-Wallis test were applied, as appropriate.ResultsSixty websites were identified. After eliminating duplicates, 11 commercial company (CC) websites were identified. Nineteen other websites were reviewed of which six overlapped with five CC websites. Most of the websites had non-professional authors (73.7%), such as laypersons and CC representatives. CC websites were significantly more likely than search term-identified websites to state that cfDNA can screen for trisomy 21 (p=0.002), trisomy 18 (p<0.0001), trisomy 13 (p<0.001), sex chromosome aneuploidies (p<0.001), and microdeletions (p=0.002).ConclusionsThis study shows that most website currently available information for expectant parents about cfDNA prenatal screening is produced by non-professional organizations. There are significant differences between the information provided by CC and Google search websites, specifically about the number of conditions screened for by cfDNA. Improving availability and quality of information about cfDNA could improve counseling future expectant parents. Inclusion of information about the potential for detection of a DSD is needed.

Report content and prenatal diagnosis of non-invasive prenatal testing for sex chromosome aneuploidy

Objective: To analyze the report content, the methods and results of prenatal diagnosis of high risk of sex chromosome aneuploidy (SCA) in non-invasive prenatal testing (NIPT). Methods: A total of 227 single pregnancy pregnant women who received genetic counseling and invasive prenatal diagnosis at Drum Tower Hospital Affiliated to the Medical School of Nanjing University from January 2015 to April 2022 due to the high risk of SCA suggested by NIPT were collected. The methods and results of prenatal diagnosis were retrospectively analyzed, and the results of chromosome karyotype analysis and chromosome microarray analysis (CMA) were compared. The relationship between NIPT screening and invasive prenatal diagnosis was analyzed. Results: (1) Prenatal diagnosis methods for 277 SCA high risk pregnant women included 73 cases of karyotyping, 41 cases of CMA and 163 cases of karyotyping combined with CMA, of which one case conducted amniocentesis secondly for further fluorescence in situ hybridization (FISH) testing. Results of invasive prenatal diagnosis were normal in 166 cases (59.9%, 166/277), and the abnormal results including one case of 45,X (0.4%, 1/277), 18 cases of 47,XXX (6.5%, 18/277), 36 cases of 47,XXY (13.0%, 36/277), 20 cases of 47,XYY (7.2%, 20/277), 1 case of 48,XXXX (0.4%, 1/277), 20 cases of mosaic SCA (7.2%, 20/277), 5 cases of sex chromosome structural abnormality or large segment abnormality (1.8%, 5/277), and 10 cases of other abnormalities [3.6%, 10/277; including 9 cases of copy number variation (CNV) and 1 case of balanced translocation]. Positive predictive value (PPV) for SCA screening by NIPT was 34.7% (96/277). (2) Among the 163 cases tested by karyotyping combined with CMA, 11 cases (6.7%, 11/163) showed inconsistent results by both methods, including 5 cases of mosaic SCA, 1 case of additional balanced translocation detected by karyotyping and 5 cases of additional CNV detected by CMA. (3) NIPT screening reports included 149 cases of "sex chromosome aneuploidy"(53.8%, 149/277), 54 cases of "number of sex chromosome increased" (19.5%, 54/277), and 74 cases of "number of sex chromosome or X chromosome decreased" (26.7%, 74/277). The PPV of "number of sex chromosome increased" and "number of sex chromosome or X chromosome decreased" were 72.2% (39/54) and 18.9% (14/74), respectively, and the difference was statistically significant (χ2=34.56, P<0.01). Conclusions: NIPT could be served as an important prenatal screening technique of SCA, especially for trisomy and mosaicism, but the PPV is comparatively low. More information of NIPT such as the specific SCA or maternal SCA might help improving the confidence of genetic counseling and thus guide clinic management. Multi technology platforms including karyotyping, CMA and FISH could be considered in the diagnosis of high risk of SCA by NIPT.

Healthcare and support experiences of adolescents and young adults diagnosed with 47,XXY, 47,XXX, and 48,XXYY.

Sex chromosome aneuploidies (SCAs) are among the most common chromosomal conditions. There is little scholarship on how adolescents and young adults (AYAs) affected by SCA engage with and adapt to their diagnosis. In order to understand how AYAs adapt to a SCA diagnosis, we conducted a secondary analysis of qualitative interviews with AYAs. Eight in-depth semi-structured interviews with individuals with a diagnosis of 47,XXY, 47,XXX, and 48,XXYY were analyzed for iterative themes related to adaptation to a SCA diagnosis in accordance with standard qualitative methodology. Our findings suggest that the process of adaptation is highly variable and complex and is mediated by external factors including diagnosis delivery and community support. Factors associated with adaptation include feeling understood and supported by healthcare providers; researching the condition; receiving hormone replacement therapy; and receiving support from a community of peers. As access to prenatal and pediatric genetic testing continues to expand, non-genetic pediatric providers are increasingly likely to interact with individuals with SCAs as part of their initial diagnostic odyssey or ongoing medical management. Understanding the diversity of lived experiences of AYAs with SCAs is helpful for healthcare providers to facilitate holistic care and provide meaningful support to patients.

Iron overload induces dysplastic erythropoiesis and features of myelodysplasia in Nrf2-deficient mice.

Iron overload (IOL) is hypothesized to contribute to dysplastic erythropoiesis. Several conditions, including myelodysplastic syndrome, thalassemia and sickle cell anemia, are characterized by ineffective erythropoiesis and IOL. Iron is pro-oxidant and may participate in the pathophysiology of these conditions by increasing genomic instability and altering the microenvironment. There is, however, lack of in vivo evidence demonstrating a role of IOL and oxidative damage in dysplastic erythropoiesis. NRF2 transcription factor is the master regulator of antioxidant defenses, playing a crucial role in the cellular response to IOL in the liver. Here, we crossed Nrf2-/- with hemochromatosis (Hfe-/-) or hepcidin-null (Hamp1-/-) mice. Double-knockout mice developed features of ineffective erythropoiesis and myelodysplasia including macrocytic anemia, splenomegaly, and accumulation of immature dysplastic bone marrow (BM) cells. BM cells from Nrf2/Hamp1-/- mice showed increased in vitro clonogenic potential and, upon serial transplantation, recipients disclosed cytopenias, despite normal engraftment, suggesting defective differentiation. Unstimulated karyotype analysis showed increased chromosome instability and aneuploidy in Nrf2/Hamp1-/- BM cells. In HFE-related hemochromatosis patients, NRF2 promoter SNP rs35652124 genotype TT (predicted to decrease NRF2 expression) associated with increased MCV, consistent with erythroid dysplasia. Our results suggest that IOL induces ineffective erythropoiesis and dysplastic hematologic features through oxidative damage in Nrf2-deficient cells.

The value of non-invasive prenatal testing for the identification of numerical and structural chromosomal abnormalities and copy number variations in the fetuses

To assess the value of non-invasive prenatal testing (NIPT) for the identification of numerical and structural chromosomal abnormalities and copy number variations (CNVs) in fetuses. 46 197 pregnant women undergoing NIPT at the Prenatal Diagnosis Center of Chenzhou First People's Hospital from January 2018 to December 2021 were selected as the study subjects. Positive cases were subjected to chromosomal karyotyping and copy number variation sequencing (CNV-seq) following amniocentesis. Nearly 50% of common chromosomal aneuploidies were found in the elder pregnant women. Among these, sex chromosome aneuploidies were mainly found in pregnant women with advanced age as well as borderline risks by serological screening. Rare autosomal aneuploidies and CNVs were mainly found in those with borderline or high risks by serological screening. The positive predictive values (PPV) for fetal chromosomal abnormalities indicated by NIPT were as follows: T21 (92.37%, 109/118), T18 (53.85%, 14/26), sex chromosome aneuploidies (45.04%, 59/131), T13 (34.62%, 9/26), CNVs (29.17%, 14/48), and rare autosomal aneuploidies (2.60%, 2/77). NIPT has a high detection rate for T21, T18, T13 and sex chromosome aneuploidies. It can also detect rare autosomal aneuploidies and CNVs, including some rare structural abnormalities, though verification is required by analyzing amniotic fluid samples.

Aneuploidy in oocytes from women of advanced maternal age: analysis of the causal meiotic errors and impact on embryo development.

In oocytes of advanced maternal age (AMA) women, what are the mechanisms leading to aneuploidy and what is the association of aneuploidy with embryo development? Known chromosome segregation errors such as precocious separation of sister chromatids explained 90.4% of abnormal chromosome copy numbers in polar bodies (PBs), underlying impaired embryo development. Meiotic chromosomal aneuploidies in oocytes correlate with AMA (>35 years) and can affect over half of oocytes in this age group. This underlies the rationale for PB biopsy as a form of early preimplantation genetic testing for aneuploidy (PGT-A), as performed in the 'ESHRE STudy into the Evaluation of oocyte Euploidy by Microarray analysis' (ESTEEM) randomized controlled trial (RCT). So far, chromosome analysis of oocytes and PBs has shown that precocious separation of sister chromatids (PSSC), Meiosis II (MII) non-disjunction (ND), and reverse segregation (RS) are the main mechanisms leading to aneuploidy in oocytes. Data were sourced from the ESTEEM study, a multicentre RCT from seven European centres to assess the clinical utility of PGT-A on PBs using array comparative genomic hybridization (aCGH) in patients of AMA (36-40 years). This included data on the chromosome complement in PB pairs (PGT-A group), and on embryo morphology in a subset of embryos, up to Day 6 post-insemination, from both the intervention (PB biopsy and PGT-A) and control groups. ESTEEM recruited 396 AMA patients: 205 in the intervention group and 191 in the control group. Complete genetic data from 693 PB pairs were analysed. Additionally, the morphology from 1034 embryos generated from fertilized oocytes (two pronuclei) in the PB biopsy group and 1082 in the control group were used for statistical analysis. Overall, 461/693 PB pairs showed abnormal segregation in 1162/10 810 chromosomes. The main observed abnormal segregations were compatible with PSSC in Meiosis I (MI) (n = 568/1162; 48.9%), ND of chromatids in MII or RS (n = 417/1162; 35.9%), and less frequently ND in MI (n = 65/1162; 5.6%). For 112 chromosomes (112/1162; 9.6%), we observed a chromosome copy number in the first PB (PB1) and second PB (PB2) that is not explained by any of the known mechanisms causing aneuploidy in oocytes. We observed that embryos in the PGT-A arm of the RCT did not have a significantly different morphology between 2 and 6 days post-insemination compared to the control group, indicating that PB biopsy did not affect embryo quality. Following age-adjusted multilevel mixed-effect ordinal logistic regression models performed for each embryo evaluation day, aneuploidy was associated with a decrease in embryo quality on Day 3 (adjusted odds ratio (aOR) 0.62, 95% CI 0.43-0.90), Day 4 (aOR 0.15, 95% CI 0.06-0.39), and Day 5 (aOR 0.28, 95% CI 0.14-0.58). RS cannot be distinguished from normal segregation or MII ND using aCGH. The observed segregations were based on the detected copy number of PB1 and PB2 only and were not confirmed by the analysis of embryos. The embryo morphology assessment was static and single observer. Our finding of frequent unexplained chromosome copy numbers in PBs indicates that our knowledge of the mechanisms causing aneuploidy in oocytes is incomplete. It challenges the dogma that aneuploidy in oocytes is exclusively caused by mis-segregation of chromosomes during MI and MII. Data were mined from a study funded by ESHRE. Illumina provided microarrays and other consumables necessary for aCGH testing of PBs. None of the authors have competing interests. Data were mined from the ESTEEM study (ClinicalTrials.gov Identifier NCT01532284).

Noninvasive prenatal screening with conventional sequencing depth to screen fetal copy number variants: A retrospective study of 19 144 pregnant women.

To investigate the detectability of noninvasive prenatal screening (NIPS) with conventional sequencing depth to detect fetal copy number variants. We performed a retrospective study in a total of 19 144 pregnant women. Their cell-free plasma DNA were assessed for trisomy 21, trisomy 18, trisomy 13, sex chromosome aneuploidies, and genome-wide copy number variants by NIPS at conventional sequencing depth. Three hundred seventy-four cases (2.0%, 374/19 144) with abnormal results were detected, which including 84 cases (0.4%, 84/19 144) with high risk of trisomy 21, 18, and 13, 90 cases (0.5%, 90/19 144) with high risk of sex chromosome abnormalities (SCA), and 44 cases (0.2%, 44/19 144) with high risk of other chromosome aneuploidies. One hundred fifty-six cases (0.8%, 156/19 144) with high risk of copy number variations (CNVs) were also detected. In following prenatal diagnosis, composite positive predictive value (PPV) of trisomy 21, 18, and 13 was 69.6% (48/69). The PPV of SCAs was 37.3% (19/51). And the PPVs for CNVs was detected as 51.0% (<5 Mb), 71.4% (5 Mb ≤ CNV ≤10 Mb), 56.5% (>10 Mb). Finally, a follow-up about the pregnancy outcomes were conducted for all available cases. NIPS yielded high PPVs for trisomy 21, 18, and 13 aneuploidies and moderate PPVs for SCAs and CNVs. The screening effectiveness was closely related to the size of CNV fragments. Larger CNVs, especially larger than 5 Mb, could be detected more accurately by NIPS in our analytic technique. Meanwhile, diagnostic confirmation by microarray analysis was highly recommended.

Contribution of Spontaneous Mutations to Quantitative and Molecular Variation at the Highly Repetitive rDNA Locus in Yeast.

The ribosomal DNA array in Saccharomyces cerevisiae consists of many tandem repeats whose copy number is believed to be functionally important but highly labile. Regulatory mechanisms have evolved to maintain copy number by directed mutation, but how spontaneous variation at this locus is generated and selected has not been well characterized. We applied a mutation accumulation approach to quantify the impacts of mutation and selection on this unique genomic feature across hundreds of mutant strains. We find that mutational variance for this trait is relatively high, and that unselected mutations elsewhere in the genome can disrupt copy number maintenance. In consequence, copy number generally declines gradually, consistent with a previously proposed model of rDNA maintenance where a downward mutational bias is normally compensated by mechanisms that increase copy number when it is low. This pattern holds across ploidy levels and strains in the standard lab environment but differs under some stressful conditions. We identify several alleles, gene categories, and genomic features that likely affect copy number, including aneuploidy for chromosome XII. Copy number change is associated with reduced growth in diploids, consistent with stabilizing selection. Levels of standing variation in copy number are well predicted by a balance between mutation and stabilizing selection, suggesting this trait is not subject to strong diversifying selection in the wild. The rate and spectrum of point mutations within the rDNA locus itself are distinct from the rest of the genome and predictive of polymorphism locations. Our findings help differentiate the roles of mutation and selection and indicate that spontaneous mutation patterns shape several aspects of ribosomal DNA evolution.

Genomic evidence of sex chromosome aneuploidy and infection-associated genotypes in the tsetse fly Glossina fuscipes, the major vector of African trypanosomiasis in Uganda.

The primary vector of the trypanosome parasite causing human and animal African trypanosomiasis in Uganda is the riverine tsetse fly Glossina fuscipes fuscipes (Gff). Our study improved the Gff genome assembly with whole genome 10× Chromium sequencing of a lab reared pupae, identified autosomal versus sex-chromosomal regions of the genome with ddRAD-seq data from 627 field caught Gff, and identified SNPs associated with trypanosome infection with genome-wide association (GWA) analysis in a subset of 351 flies. Results from 10× Chromium sequencing greatly improved Gff genome assembly metrics and assigned a full third of the genome to the sex chromosome. Results from ddRAD-seq suggested possible sex-chromosome aneuploidy in Gff and identified a single autosomal SNP to be highly associated with trypanosome infection. The top associated SNP was ∼1100bp upstream of the gene lecithin cholesterol acyltransferase (LCAT), an important component of the molecular pathway that initiates trypanosome lysis and protection in mammals. Results suggest that there may be naturally occurring genetic variation in Gff in genomic regions in linkage disequilibrium with LCAT that can protect against trypanosome infection, thereby paving the way for targeted research into novel vector control strategies that can promote parasite resistance in natural populations.

Late first-trimester ultrasound findings can alter management after high-risk NIPT result.

To evaluate the impact of detailed late first-trimester ultrasound (LFTU) on the positive predictive value (PPV) of a high-risk non-invasive prenatal test (NIPT) result for various chromosomal abnormalities. This was a retrospective study of all cases undergoing invasive prenatal testing from three tertiary providers of obstetric ultrasound over 4 years, each using NIPT as a first-line screening test. Data were collected from pre-NIPT ultrasound, NIPT, LFTU, placental serology and later ultrasound examinations. Prenatal testing for chromosomal abnormalities was performed by microarray, initially using array comparative genomic hybridization and then single nucleotide polymorphism (SNP) array for the last 2 years. Uniparental disomy testing was performed by SNP array during all 4 years. The majority of NIPT tests were analyzed using the Illumina platform, initially confined to the assessment of the common autosomal trisomies, sex chromosome aneuploidies and rare autosomal trisomies (RAT), then extending to genome-wide analysis for the last 2 years. Amniocentesis or chorionic villus sampling (CVS) was performed on 2657 patients, 1352 (51%) of whom had undergone prior NIPT, with 612 (45%) of these returning a high-risk result and meeting the inclusion criteria for the study. LFTU findings significantly affected the PPV of the NIPT result for trisomies 13 (T13), 18 (T18) and 21 (T21), monosomy X (MX) and RAT but not for the other sex chromosomal abnormalities or segmental imbalances (> 7 Mb). Abnormal LFTU increased the PPV close to 100% for T13, T18, T21, MX and RAT. The magnitude of the change in PPV was highest for the most severe chromosomal abnormalities. When LFTU was normal, the incidence of confined placental mosaicism (CPM) was highest in those with a high-risk NIPT result for T13, followed by T18 and T21. After normal LFTU, the PPV for T21, T18, T13 and MX decreased to 68%, 57%, 5% and 25%, respectively. LFTU after a high-risk NIPT result can alter the PPV for many chromosomal abnormalities, assisting counseling regarding invasive prenatal testing and pregnancy management. The high PPVs of NIPT for T21 and T18 are not sufficiently modified by normal LFTU findings to alter management. These at-risk patients should be offered CVS for earlier diagnosis, particularly given the low rate of CPM associated with these aneuploidies. Patients with a high-risk NIPT result for T13 and normal LFTU findings often wait for amniocentesis or avoid invasive testing altogether given the low PPV and higher rate of CPM in this context. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Influences of sex chromosome aneuploidy on height, weight, and body mass index in human childhood and adolescence.

Sex chromosome aneuploidies (SCAs) are collectively common conditions caused by carriage of a sex chromosome dosage other than XX for females and XY for males. Increases in sex chromosome dosage (SCD) have been shown to have an inverted-U association with height, but we lack combined studies of SCA effects on height and weight, and it is not known if any such effects vary with age. Here, we study norm-derived height and weight z-scores in 177 youth spanning 8 SCA karyotypes (XXX, XXY, XYY, XXXX, XXXY, XXYY, XXXXX, and XXXXY). We replicate a previously described inverted-U association between mounting SCD and height, and further show that there is also a muted version of this effect for weight: both phenotypes are elevated until SCD reaches 4 for females and 5 for males but decrease thereafter. We next use 266 longitudinal measures available from a subset of karyotypes (XXX, XXY, XYY, and XXYY) to show that mean height in these SCAs diverges further from norms with increasing age. As weight does not diverge from norms with increasing age, BMI decreases with increasing age. These findings extend our understanding of growth as an important clinical outcome in SCA, and as a key context for known effects of SCA on diverse organ systems that scale with body size.

The preimplantation genetic testing for monogenic disorders strategy for blocking the transmission of hereditary cancers through haplotype linkage analysis by karyomapping.

Providing feasible preimplantation genetic testing strategiesfor monogenic disorders (PGT-M) for prevention and control of genetic cancers. Inclusion of families with a specific pathogenic mutation or a clear family history of genetic cancers. Identification of the distribution of hereditary cancer-related mutations in families through genetic testing. After a series of assisted reproductive measures such as down-regulation, stimulation, egg retrieval, and in vitro fertilization, a biopsy of trophectoderm cells from a blastocyst was performed for single-cell level whole-genome amplification (WGA). Then, the detection of chromosomal aneuploidies was performed by karyomapping. Construction of a haplotype-based linkage analysis to determine whether the embryo carries the mutation. Meanwhile, we performed CNV testing. Finally, embryos can be selected for transfer, and the results will be verified in 18-22 weeks after pregnancy. Six couples with a total of 7 cycles were included in our study. Except for cycle 1 of case 5 which did not result in a transferable embryo, the remaining 6 cycles produced transferable embryos and had a successful pregnancy. Four couples have had amniotic fluid tests to confirm that the fetus does not carry the mutation, while 1 couple was not tested due to insufficient pregnancy weeks. And the remaining couples had to induce labor due to fetal megacystis during pregnancy. Our strategy has been proven to be feasible. It can effectively prevent transmission of hereditary cancer-related mutations to offspring during the prenatal stage.

Multidimensional Analysis of a Cell-Free DNA Whole Methylome Sequencing Assay for Early Detection of Gastric Cancer: Protocol for an Observational Case-Control Study.

Commonly used noninvasive serological indicators serve as a step before endoscope diagnosis and help identify the high-risk gastric cancer (GC) population. However, they are associated with high false positives and high false negatives. Alternative noninvasive approaches, such as cancer-related features in cell-free DNA (cfDNA) fragments, have been gradually identified and play essential roles in early cancer detection. The integrated analysis of multiple cfDNA features has enhanced detection sensitivity compared to individual features. This study aimed to develop and validate an assay based on assessing genomic-scale methylation and fragmentation profiles of plasma cfDNA for early cancer detection, thereby facilitating the early diagnosis of GC. The primary objective is to evaluate the overall specificity and sensitivity of the assay in predicting GC within the entire cohort, and subsequently within each clinical stage of GC. The secondary objective involved investigating the specificity and sensitivity of the assay in combination with possible serological indicators. This is an observational case-control study. Blood samples will be prospectively collected before gastroscopy from 180 patients with GC and 180 nonmalignant control subjects (healthy or with benign gastric diseases). Cases and controls will be randomly divided into a training and a testing data set at a ratio of 2:1. Plasma cfDNA will be isolated and extracted, followed by bisulfite-free low-depth whole methylome sequencing. A multidimensional model named Thorough Epigenetic Marker Integration Solution (THEMIS) will be constructed in the training data set. The model includes features such as the methylated fragment ratio, chromosomal aneuploidy of featured fragments, fragment size index, and fragment end motif. The performance of the model in distinguishing between patients with cancer and noncancer controls will then be evaluated in the testing data set. Furthermore, GC-related biomarkers, such as pepsinogen, gastrin-17, and Helicobacter pylori, will be measured for each patient, and their predictive accuracy will be assessed both independently and in combination with the THEMIS model. Recruitment began in November 2022 and will be ended in April 2024. As of August 2022,250 patients have been enrolled. The final data analysis is anticipated to be completed by September 2024. This is the first registered case-control study designed to investigate a stacked ensemble model integrating several cfDNA features generated from a bisulfite-free whole methylome sequencing assay. These features include methylation patterns, fragmentation profiles, and chromosomal copy number changes, with the aim of identifying the GC population. This study will determine whether multidimensional analysis of cfDNA will prove to be an effective strategy for distinguishing patients with GC from nonmalignant individuals within the Chinese population. We anticipate the THEMIS model will complement the standard-of-care screening and aid in identifying high-risk patients for further diagnosis. ClinicalTrial.gov NCT05668910; https://www.clinicaltrials.gov/study/NCT05668910. DERR1-10.2196/48247.

Application of non-invasive prenatal testing to 91,280 spontaneous pregnancies and 3477 pregnancies conceived by in vitro fertilization

BackgroundMany clinical studies based on spontaneous pregnancies (SPs) have demonstrated the superiority of non-invasive prenatal testing (NIPT), and the question of whether this technology is suitable for offspring conceived by assisted reproductive technology has attracted attention. This study aimed to evaluate the application value of NIPT in screening for trisomy (T)21, T18, T13 and sex chromosome aneuploidy (SCA) in pregnant women who conceived by in vitro fertilization (IVF).ResultsIn total, there were 804 high-risk cases [0.88% (804/91280), singleton = 795, twin = 9] in the SP group. Among the 558 invasive prenatal diagnosis (IPD) cases (singleton = 556, twin = 2), 343 (singleton = 342, twin = 1) were true positive, including 213 cases of T21, 28 of T18, 5 of T13 and 97 (singleton = 96, twin = 1) of SCA. The positive predictive values (PPVs) of T21, T18, T13, SCA and T21/T18/T13 combined in singleton pregnancy were 89.12% (213/239), 51.85% (28/54), 21.74% (5/23), 40.00% (96/240), and 77.85% (246/316), respectively, and the PPV of SCA in twin pregnancy was 100.00%. In the IVF group, IPD was performed in 19 (singleton = 16, twin = 3) of the 27 high-risk cases [0.78% (27/3477), singleton = 16, twin = 3], of which 9 (singleton = 8, twin = 1) were true positive, including 5 cases (singleton = 4, twin = 1) of T21 and 4 of SCA. The PPVs of singleton T21, SCA and T21/T18/T13 combined were 66.67% (4/6), 50.00% (4/8) and 57.14% (4/7), respectively, and the PPV of twin T21 was 100.00% (1/1). There were no significant differences in PPV among T21, SCA and T21/T18/T13 combined in singletons between the groups (89.12% vs. 66.67%, p = 0.09; 40.00% vs. 50.00%, p = 0.57; 77.85% vs. 57.14%, p = 0.20). The sensitivity and specificity were higher for singleton and twin pregnancies in the two groups. Based on follow-up results, 1 case of false negative T21 was found in the singleton SP group. Additionally, the mean foetal fraction (FF) of the IVF group was lower than that of the SP group (11.23% vs. 10.51%, p < 0.05).ConclusionNIPT has high sensitivity and specificity in screening chromosomal aneuploidies in both IVF pregnancy and spontaneous pregnancy, so it is an ideal screening method for IVF pregnancy.

Alteration of relative telomere length and telomerase reverse transcriptase expression in the granulosa cells of women during aging and assessment of in vitro fertilization outcomes.

Telomere attrition plays a critical role in the reproductive aging process in humans. Telomere length (TL) is typically regulated by telomerase, the main component of which is telomerase reverse transcriptase (TERT). The aim of the present study was to investigate the changes of relative TL (RTL) and TERT expression in granulosa cells (GCs) during aging and its association with reproduction. Clinical data on the frozen‑thawed embryo transfer cycles of older (>35year old) and younger (≤35year old) women from a single center over a 3‑year period were retrospectively analyzed. Preimplantation genetic testing for chromosome aneuploidies in older women during the same period was also analyzed. Following the analysis of the data, several biological characteristics of senescent GCs were explored. In addition, a total of 160women who were undergoing their first fresh cycle of invitro fertilization (IVF) or intracytoplasmic sperm injection were included in the study. GCs were collected from all participants. The changes of RTL and TERT expression in GCs during aging were investigated using quantitative PCR and western blotting. The associations of RTL and TERT with IVF outcomes were also assessed. The clinical data demonstrated that the pregnancy and live birth rates of women aged >35years were ~20% lower than those of women aged ≤35years, and the number of embryos with aneuploidy was 7‑fold of that without euploidy in the older age group. An aging‑induced change in follicle stimulating hormone receptor expression was observed. A shorter TL and increased TERT expression were detected in the older women. A significant inverse correlation between the expression levels of TERT and oocyte yield was identified. However, no association of RTL and TERT with blastocyst formation rate and the probability of clinical pregnancy was detected. It may be concluded that RTL and TERT alterations in GCs are potential determinants of ovarian aging. TERT expression in GCs appears to be a potential biomarker for the prediction of ovarian response, which provides a novel strategy for the assessment of female fertility.

Chromosomal aneuploidy and pregnancy outcomes for D5/D6 blastocysts from patients undergoing PGT-A treatment

To compare the prevalence of chromosomal aneuploidies and pregnancy outcomes of D5 and D6 blastocysts subjected to preimplantation genetic testing for aneuploidy (PGT-A). Clinical and laboratory data of 268 couples who underwent PGT-A at the Reproductive Center of the First Affiliated Hospital of Zhengzhou University from September 2018 to September 2020 were collected. The prevalence of chromosomal aneuploidies and pregnancy outcomes of D5/D6 biopsied blastocysts were compared. Compared with D6 blastocysts, the euploidy rate of D5 blastocysts was significantly higher (49.1% vs. 41.1%, P = 0.001 1), whilst their aneuploidy rate was significantly lower (50.9% vs. 58.9%, P = 0.001 1). The rate of numerical abnormalities of D6 blastocysts was significantly higher than that of D5 blastocysts (27.9% vs. 20.2%, P = 0.000 5). For patients under 35 years old, the euploidy rate of D5 blastocysts was significantly higher than that of D6 blastocysts (53.8% vs. 44.3%, P = 0.001), whilst the numerical abnormality rate was significantly lower (16.3% vs. 23.9%, P = 0.001). For both D5 and D6 blastocysts, the euploidy rates for patients <= 35 were significantly higher than those for > 35. The elder group had the lowest rates for aneuploidies and live births. Compared with those receiving D6 blastocysts transplantation, the pregnancy rate, implantation rate and live birth rate for those receiving thawed D5 blastocysts transplantation were significantly higher (60.2% vs.37.0%, P = 0.000 3; 59.1% vs.37.0%, P = 0.000 6; 47.7% vs. 28.3%, P = 0.002). For patients undergoing PGT-A, the chromosomal euploidy rate for D5 blastocysts is higher than that for D6 blastocysts, and the clinical outcome of D5 blastocysts with normal signal is better than that of D6 blastocysts. Elder patients have a higher rate of aneuploidies.

Clinical Potential of Expanded Noninvasive Prenatal Testing for Detection of Aneuploidies and Microdeletion/Microduplication Syndromes.

We aimed to evaluate the clinical performance of expanded noninvasive prenatal testing (NIPT-Plus) for the detection of aneuploidies and microdeletion/microduplication syndromes. A total of 7177 pregnant women were enrolled in the study from June 2020 to March 2022 at Xijing Hospital, China. Cases with NIPT-Plus-positive results were further confirmed by chromosomal karyotyping and a chromosomal microarray analysis. A total of 112 positive cases (1.56%) were identified by NIPT-Plus, including 60 chromosome aneuploidies and 52 microdeletion/microduplication syndromes. Ninety-five cases were validated by amniocentesis, and 57 were confirmed with true-positive results, comprising 18 trisomy 21, 4 trisomy 18, 1 trisomy 13, 17 sex chromosome aneuploidies, 1 other aneuploidy, and 16 microdeletion/microduplication syndromes. The positive predictive value of total chromosomal abnormalities was 60% (57/95). For trisomy 21, trisomy 18, trisomy 13, sex chromosome aneuploidies, other aneuploidies and microdeletion/microduplication syndromes, the sensitivity was all 100%, the specificity was 100, 99.986, 100, 99.888, 99.958, and 99.636%, and the positive predictive value was 100, 80, 100, 68, 25, and 38.10%, respectively. For all clinical characteristics, the abnormal maternal serum screening group was found to have the highest prevalence of chromosomal abnormalities (1.54%), and the ultrasound abnormality group presented the highest positive predictive value (73.33%). NIPT-Plus has great potential for the detection of aneuploidies and microdeletion/microduplication syndromes owing to its high sensitivity, safety, and specificity, which greatly reduces unnecessary invasive procedures and the risk of miscarriage and allows informed maternal choice.

The Predictive Value of Prenatal Cell-Free DNA Testing for Rare Autosomal Trisomies: A Systematic Review and Meta-analysis

ABSTRACT Noninvasive prenatal testing has been a reliable method for prenatal screening for the common autosomal trisomies for the last decade. It has been analyzed in many prospective studies for accuracy in screening for the most common trisomies—13, 18, and 21—and the technology has continued to progress. With high accuracy for common trisomies, advances are attempting to expand noninvasive prenatal testing for identifying rare autosomal trisomies, such as trisomies 7, 15, 16, and 22; sex chromosome aneuploidies; and segmental copy number variants. Although cell-free DNA (cfDNA) technology is now available to screen for these abnormalities, accuracy and detection rates have not been well studied. This systematic review analyzes and reports the diagnostic accuracy of cfDNA screening for the rare autosomal trisomies. This review included case series with 10 or more cases that reported on the accuracy of cfDNA in reporting rare autosomal trisomies that were confirmed by diagnostic results or postnatal genetic testing; the final review included 31 studies. Methodological analysis found the risk of bias to be high in most studies, with only 5 rated as high quality and low risk in all domains. All studies included in the final analyses were published between 2017 and 2022, and study populations ranged from 14 to 153,575 patients. Indications for screening and characteristics of the patients varied from study to study, with 12 studies in high-risk women, 10 studies in the general obstetric population, and 9 studies without inclusion of underlying risk factors and indications. Whole-genome sequencing was used in all studies as testing methodology. Testing timing varied and was performed anywhere from gestational week 8 to week 39. In the 3 studies that analyzed sensitivity and specificity of cfDNA testing, sensitivity ranged from 87.2% to 100%, and specificity ranged from 90.7% to 99.9%. In all 3 of these studies, there were significant limitations that led authors to acknowledge the difficulty of drawing clear conclusions about sensitivity and specificity from their data. Meta-analysis performed for positive predictive value (PPV) provided a pooled estimate of 11.46% (95% confidence interval [CI], 7.80%–15.65%). Sensitivity analysis including only studies at low risk of bias gave a PPV of 9.13% (95% CI, 2.49%–18.76%). Analysis was performed again with groups divided into high or low background risk, with a slightly higher PPV in the higher background risk group, but no significant difference between these groups (P = 0.595). Statistical heterogeneity was not explained by year of publication or baseline risk of participants but could be largely explained by rate of diagnostic follow-up. Studies with a follow-up rate of less than 50% showed a PPV of 23.69% (95% CI, 9.21%–41.94%), whereas studies with a follow-up rate greater than 50% reported a PPV of 8.80% (95% CI, 6.08%–11.90%). Based on the results of this systematic review and meta-analysis, it is likely that previously reported PPVs of cfDNA's diagnostic accuracy for detecting rare autosomal trisomies are overestimated. A reason for this could be lower follow-up rates as well as testing bias in women with high-risk cfDNA results. One reason for the low prevalence of rare autosomal trisomies is that many confirmed cases result in miscarriage before 12 weeks of gestation. Pregnancies that continue and that are not mosaic often experience major complications. The occurrence of mosaicism may impact the PPV, as mosaicism carries some risks but is sometimes not detected from cfDNA samples. This study was limited by the details included in the studies analyzed; this caused significant statistical heterogeneity, which limits the conclusions that can be drawn. In addition, detection rates may differ by type of cfDNA test, and this analysis did not stratify by type of test. The results of this analysis are consistent with previous literature on detection of rare autosomal trisomies in the general population and show that even with a high specificity and sensitivity for cfDNA testing in general, care should be taken in making clinical decisions on the part of both providers and patients in instances where a rare autosomal trisomy is suspected.

Cognition, Academic Achievement, Adaptive Behavior, and Quality of Life in Child and Adolescent Boys with Klinefelter Syndrome.

Klinefelter syndrome (KS; 47, XXY), the most common sex chromosome aneuploidy in males, is characterized by testicular failure and testosterone deficiency as well as a variety of cognitive, social, and emotional challenges. In the current study, we aimed to clarify the cognitive-behavioral profile of peripubertal boys with KS using measures of cognition, academic achievement, adaptive behavior, and quality of life. We compared 47 boys with KS (7-16 years of age) with 55 performance IQ-matched boys without KS on measures of cognition (WISC-V), executive function (BRIEF-2), academic achievement (KTEA-3), adaptive behavior (Vineland-3), and quality of life (PROMIS). In exploratory analyses, we examined associations among these measures and potential associations with pubertal metrics. Boys with KS demonstrated a significantly different profile of cognition, behavioral ratings of executive function, academic achievement, adaptive behavior, and quality of life compared with their typically developing peers, with, on average, lower functioning. The groups showed significantly different correlations between cognition and aspects of quality of life. No associations were observed between behavior and pubertal development. Taken together, these findings indicated that boys with KS are at increased risk for cognitive difficulties, which may affect academic achievement, adaptive behavior, and quality of life. Although initial exploratory analyses indicated that the magnitude of these alterations was not correlated with severity of testicular failure, longitudinal analyses currently being conducted by our group may help clarify the trajectory of these difficulties through the pubertal transition and testosterone replacement.

Evaluation of the clinical utility of extended non-invasive prenatal testing in the detection of chromosomal aneuploidy and microdeletion/microduplication

BackgroundWith the development of whole-genome sequencing technology, non-invasive prenatal testing (NIPT) has been applied gradually to screen chromosomal microdeletions and microduplications that cannot be detected by traditional karyotyping. However, in NIPT, some false positives and false negatives occur. This study aimed to investigate the applicability of extended NIPT (NIPT-PLUS) in the detection of chromosomal aneuploidy and microdeletion/microduplication syndrome (MMS).MethodsA total of 452 pregnancies that underwent prenatal diagnostic testing (amniocentesis or chorionic villus sampling) by chromosomal microarray analysis (CMA), were screened by NIPT-PLUS from the peripheral blood sample of the pregnant women. The results of the two tested items were compared and analysed.ResultsOf the 452 cases, 335 (74.12%) had positive CMA results, and 117 (25.88%) had no abnormal results. A total of 86 cases of trisomy 21, 18 and 13 and sex chromosome aneuploidy (SCA) were detected by CMA and NIPT-PLUS, with a detection rate of 96.51% (83/86). Among them, the detection rates of T18, T13; 47, XXY; 47, XXX and 47 XYY were 100%, and the detection rates of T21 and 45 XO were 96.55% and 90%, respectively. The detection sensitivity of rare chromosomal trisomy (RAT) was 80% (4/5). The positive predictive values of NIPT-PLUS for chromosome aneuploidy T21, T18 and T13 and for SCA and RAT were 90.32%, 87.50%, 25.00%, 88.89% and 50%, respectively. A total of 249 cases (74.32%) of chromosomal MMS were detected by CMA. The detection rate of NIPT-PLUS was 63.86% (159/249), and 90 cases (36.14%) were missed. The larger the MMS fragment, the higher the NIPT-PLUS detection sensitivity. In addition, most small fragments were of maternal origin.ConclusionThe comparison between the CMA and NIPT-PLUS techniques shows that NIPT-PLUS has high sensitivity for detecting chromosomal aneuploidy and chromosomal copy number variations (CNVs) with fragments > 5 M. However, the sensitivity of CNV for fragments < 5 M is low, and the missed detection rate is high. Additionally, confined placental mosaicism and foetal mosaicism are the key factors causing false negatives in NIPT-PLUS, while maternal chromosomal abnormalities and confined placental mosaicism are key contributors to false positives, so appropriate genetic counselling is especially important for pregnant women before and after NIPT-PLUS testing.