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It remains unclear whether recent changes in the prognosis and management of patients with trisomy 13 impact patient survival. We investigated changes in survival of patients with trisomy 13 in Japan. Data from the Vital Statistics Database in Japan was retrieved to examine the association of sex, surgical history, and years of birth and death with changes in survival patterns in 1164 patients with trisomy 13 between 1995 and 2021. The rates of deaths due to trisomy 13 increased from 9.8% to 23.1% in those over 1 year of age and from 7.3% to 19.2% in those within 24 h of birth between 1995 and 2021. The median survival time was longer in 2009-2021 than in 1996-2008 (40 vs. 84 days, p < 0.001). The median survival time and the rate of patients with surgical history increased from 91 days and 16.0% in 1996-2008 to 179 days and 28.0% in 2009-2021, respectively. Median survival time among patients with trisomy 13 has increased over the last 26 years, with almost 1 in 3 patients currently surviving for more than 1 year. The increased surgical intervention rate might have contributed to this improvement., (© 2024 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)

Objective: In singleton pregnancies, the use of cell-free DNA (cfDNA) analysis as a screening test for common fetal trisomies has spread worldwide though we still lack sufficient data for its use in triplet pregnancies. The objective of this study is to assess the performance of cfDNA testing in detecting fetal aneuploidies in triplet pregnancies as a first-tier test., Method: We performed a retrospective cohort study including data from pregnant women with a triplet pregnancy who underwent cfDNA testing between May 1, 2017, and January 15, 2020. cfDNA was obtained by massive parallel sequencing (VeriSeq NIPT solution; Illumina®). The objectives of the study were to assess the diagnostic performance of cfDNA testing for trisomy 21 (T21) (primary outcome), trisomy 18 (T18) and 13 (secondary outcomes)., Results: During the study period, cfDNA testing was performed in 255 women with triplet pregnancy, of which 165 (64.7%) had a neonatal outcome available. Three tests were positive for T21, one of which was confirmed by an antenatal karyotype, and the other was confirmed at birth. The third case did not undergo an invasive procedure and was not confirmed at birth (false positive). In one case, cfDNA testing was positive for T18 and was confirmed by an antenatal karyotype. There were no cases of trisomy 13 in the cohort. The no-call rate was 2.4% at first sampling. Fifty-eight (22.7%) women had embryo reduction, which in 40 (69%) of whom was performed after the cfDNA test result., Conclusion: cfDNA testing could be offered as primary screening for main fetal aneuploidies in triplet pregnancies after provision of appropriate patient information., (© 2024 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

This review article delves into the rapidly advancing domain of prenatal diagnostics, with a primary focus on the detection and management of chromosomal abnormalities such as trisomy 13 ("Patau syndrome)", "trisomy 18 (Edwards syndrome)", and "trisomy 21 (Down syndrome)". The objective of the study is to examine the utilization and effectiveness of novel computational methodologies, such as "machine learning (ML)", "deep learning (DL)", and data analysis, in enhancing the detection rates and accuracy of these prenatal conditions. The contribution of the article lies in its comprehensive examination of advancements in "Non-Invasive Prenatal Testing (NIPT)", prenatal screening, genomics, and medical imaging. It highlights the potential of these techniques for prenatal diagnosis and the contributions of ML and DL to these advancements. It highlights the application of ensemble models and transfer learning to improving model performance, especially with limited datasets. This also delves into optimal feature selection and fusion of high-dimensional features, underscoring the need for future research in these areas. The review finds that ML and DL have substantially improved the detection and management of prenatal conditions, despite limitations such as small sample sizes and issues related to model generalizability. It recognizes the promising results achieved through the use of ensemble models and transfer learning in prenatal diagnostics. The review also notes the increased importance of feature selection and high-dimensional feature fusion in the development and training of predictive models. The findings underline the crucial role of AI and machine learning techniques in early detection and improved therapeutic strategies in prenatal diagnostics, highlighting a pressing need for further research in this area., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Competing Interests: Conflict of interest The authors have no conflicts of interest relevant to this article.

Competing Interests: Conflict of interest The authors have no conflicts of interest relevant to this article.

The objective of this work was to identify phenotypic features and cytogenetic aspects of trisomy 13 in Moroccan population. The retrospective study was conducted on a group of 9 cases diagnosed cytogenetically with trisomy 13. The study of sex ratio showed a slight female dominance in our group of cases. The major clinical findings included: Holoprosencephaly, microphthalmia and anophthalmia, coloboma of iris, cleft lip and palate, nasal and ear abnormalities, retrognathism and sloping forehead, polydactyly, capillary hemangiomas, omphalocele, congenital heart defect, renal abnormalities, cryptorchidism, language delay. The cytogenetic study showed the dominance of the free and homogeneous trisomy 13 (56%). Patients who have this formula are dead at an early age (does not exceed one month). However, each of the chromosomal formula, trisomy 13 by translocation and partial trisomy 13 t (13;18), was found in 20% of our patients. The partial trisomy 13 t (13;18) is the only variant that is still alive and the patients with this anomaly suffer mainly from renal and cardiac anomalies with slight dysmorphia and psychomotor retardation. Our study shows the interest of the cytogenetic analysis in the diagnosis accuracy and in the genetic counseling of patients with Patau syndrome and their parents., (© 2023 Hammou HA et al.)

Trisomy is the presence of one extra copy of an entire chromosome or its part in a cell nucleus. In humans, autosomal trisomies are associated with severe developmental abnormalities leading to embryonic lethality, miscarriage or pronounced deviations of various organs and systems at birth. Trisomies are characterized by alterations in gene expression level, not exclusively on the trisomic chromosome, but throughout the genome. Here, we applied the high-throughput chromosome conformation capture technique (Hi-C) to study chromatin 3D structure in human chorion cells carrying either additional chromosome 13 (Patau syndrome) or chromosome 16 and in cultured fibroblasts with extra chromosome 18 (Edwards syndrome). The presence of extra chromosomes results in systematic changes of contact frequencies between small and large chromosomes. Analyzing the behavior of individual chromosomes, we found that a limited number of chromosomes change their contact patterns stochastically in trisomic cells and that it could be associated with lamina-associated domains (LAD) and gene content. For trisomy 13 and 18, but not for trisomy 16, the proportion of compacted loci on a chromosome is correlated with LAD content. We also found that regions of the genome that become more compact in trisomic cells are enriched in housekeeping genes, indicating a possible decrease in chromatin accessibility and transcription level of these genes. These results provide a framework for understanding the mechanisms of pan-genome transcription dysregulation in trisomies in the context of chromatin spatial organization.

Objective: We aimed to evaluate the clinical performance of expanded noninvasive prenatal testing (NIPT-Plus) for the detection of aneuploidies and microdeletion/microduplication syndromes., Methods: 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., Results: 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%)., Conclusions: 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., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Analysis of cell-free DNA from maternal blood provides effective screening for trisomy 21 in singleton pregnancies. Data on cell-free DNA screening in twin gestations are promising although limited. In previous twin studies, cell-free DNA screening was primarily performed in the second trimester and many studies did not report chorionicity., Objective: This study aimed to evaluate the screening performance of cell-free DNA for trisomy 21 in twin pregnancies in a large, diverse cohort. A secondary aim was to evaluate screening performance for trisomy 18 and trisomy 13., Study Design: This was a retrospective cohort study of twin pregnancies from 17 centers for which cell-free DNA screening was performed from December 2011 to February 2020 by one laboratory using massively parallel sequencing technology. Medical record review was conducted for all newborns and data on the birth outcome, the presence of any congenital abnormalities, phenotypic appearance at birth, and any chromosomal testing that was undertaken in the antenatal or postnatal period were extracted. Cases with a possible fetal chromosomal abnormality with no genetic test results were reviewed by a committee of maternal-fetal medicine geneticists. Cases with a vanishing twin and inadequate follow-up information were excluded. A minimum of 35 confirmed cases of trisomy 21 was required to capture a sensitivity of at least 90% with a prevalence of at least 1.9% with 80% power. Test characteristics were calculated for each outcome., Results: A total of 1764 samples were sent for twin cell-free DNA screening. Of those, 78 cases with a vanishing twin and 239 cases with inadequate follow-up were excluded, leaving a total of 1447 cases for inclusion in the analysis. The median maternal age was 35 years and the median gestational age at cell-free DNA testing was 12.3 weeks. In total, 81% of the twins were dichorionic. The median fetal fraction was 12.4%. Trisomy 21 was detected in 41 of 42 pregnancies, yielding a detection rate of 97.6% (95% confidence interval, 83.8-99.7). There was 1 false negative and no false positive cases. Trisomy 21 was detected in 38 out of 39 dichorionic twin pregnancies, yielding a detection rate of 97.4% (95% confidence interval, 82.6-99.7). Trisomy 18 was detected in 10 of the 10 affected pregnancies. There was 1 false positive case. Trisomy 13 was detected in 4 of the 5 cases, yielding a detection rate of 80% (95% confidence interval, 11.1-99.2). There was one false negative and no false positive cases. The nonreportable rate was low at 3.9 %., Conclusion: Cell-free DNA testing is effective in screening for trisomy 21 in twin gestations from the first trimester of pregnancy. Detection of trisomy 21 was high in dichorionic and monochorionic twins, and the nonreportable result rates were low. This study included high numbers of cases of trisomy 18 and 13 when compared with the current literature. Although screening for these conditions in twins seems to be promising, the numbers were too small to make definitive conclusions regarding the screening efficacy for these conditions. It is possible that cell-free DNA testing performance may differ among laboratories and vary with screening methodologies., (Copyright © 2023. Published by Elsevier Inc.)

Objective: To validate a fetus with high risk for trisomy 13 suggested by non-invasive prenatal testing (NIPT)., Methods: The fetus was selected as the study subject after the NIPT detection at Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences on February 18, 2019. Clinical data of the pregnant woman was collected. Fluorescence in situ hybridization (FISH), chromosomal karyotyping analysis and chromosomal microarray analysis (CMA) were carried out on amniotic fluid and umbilical cord blood and the couple's peripheral blood samples. Copy number variation sequencing (CNV-seq) was also performed on the placental and amniotic fluid samples following induced labor., Results: The pregnant woman, a 38-year-old G4P1 gravida, was found to have abnormal fetal development by prenatal ultrasonography. NIPT test suggested that the fetus has a high risk for trisomy 13. Chromosomal karyotyping analysis of fetal amniotic fluid and umbilical cord blood were 46,XN,add(13)(p10). The result of CMA was arr[hg19]1q41q44(223937972&#95;249224684)×3, with the size of the repeat fragment being approximately 25.29 Mb, the fetal karyotype was thereby revised as 46,XN,der(13)t(1;13)(q41;p10). Chromosomal karyotyping analysis and CMA of the parents' peripheral blood samples showed no obvious abnormality. The CNV-seq analysis of induced placenta revealed mosaicisms of normal karyotype and trisomy 13. The CNV-seq test of induced amniotic fluid confirmed a duplication of chr1:22446001&#95;249220000 region spanning approximately 24.75 Mb, which was in keeping with the CMA results of amniotic fluid and umbilical cord blood samples., Conclusion: NIPT may yield false positive result due to placenta mosaicism. Invasive prenatal diagnosis should be recommended to women with a high risk by NIPT test. And analysis of placenta can explain the inconsistency between the results of NIPT and invasive prenatal diagnosis.

Background: Noninvasive prenatal testing (NIPT) has been widely adopted in prenatal examination for fetal chromosomal aneuploidy. The present study aimed to evaluate the clinical features of NIPT for both common trisomy and sex chromosome aneuploidy (SCA)., Methods: A total of 24,164 pregnant women with NIPT testing from July 2020 to June 2022 were recruited at the Linping Maternity and Child Health Care Hospital., Results: Ninety cases showed high risk of trisomy 21/18/13 with karyotype results available, and the sensitivity, specificity, and positive predictive value (PPV) were 98.41%, 99.88% and 68.89%, respectively. The three most important reasons for screening were advanced maternal age (AMA, 28.06%), intermediate risk of prenatal screening (20.34%) and Multiple of medium (MoM) abnormality of prenatal screening (17.38%). High risk of NIPT results with Z-score ≥15 have a higher PPV when compared to those with 3 ≤ Z-score < 10, and 10 ≤ Z-score < 15. Meanwhile, 97 pregnant women received positive results for fetal sex chromosome aneuploidy (SCA) in NIPT. In addition, the rate for further diagnostics of SCA was 64.95% and the PPV of SCA was 50.79%., Conclusions: Our data show that NIPT has a promising future in prenatal screening for genetic abnormalities of the fetus, and that the accuracy of NIPT is closely related to Z-score., Competing Interests: The authors declare no conflict of interest., (© 2023 The Author(s). Published by Discovery Medicine.)

Objective: To investigate the survival to 10 years of age of children with trisomy 13 (T13) and children with trisomy 18 (T18), born 1995-2014., Design: Population-based cohort study that linked mortality data to data on children born with T13 or T18, including translocations and mosaicisms, from 13 member registries of EUROCAT, a European network for the surveillance of congenital anomalies., Setting: 13 regions in nine Western European countries., Patients: 252 live births with T13 and 602 with T18., Main Outcome Measures: Survival at 1 week, 4 weeks and 1, 5 and 10 years of age estimated by random-effects meta-analyses of registry-specific Kaplan-Meier survival estimates., Results: Survival estimates of children with T13 were 34% (95% CI 26% to 46%), 17% (95% CI 11% to 29%) and 11% (95% CI 6% to 18%) at 4 weeks, 1 and 10 years, respectively. The corresponding survival estimates were 38% (95% CI 31% to 45%), 13% (95% CI 10% to 17%) and 8% (95% CI 5% to 13%) for children with T18. The 10-year survival conditional on surviving to 4 weeks was 32% (95% CI 23% to 41%) and 21% (95% CI 15% to 28%) for children with T13 and T18, respectively., Conclusions: This multi-registry European study found that despite extremely high neonatal mortality in children with T13 and T18, 32% and 21%, respectively, of those who survived to 4 weeks were likely to survive to age 10 years. These reliable survival estimates are useful to inform counselling of parents after prenatal diagnosis., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

This study evaluated prenatal screening test performance and the prevalence of common aneuploidies at Siriraj Hospital, Thailand. We collected data from screening tests which are first-trimester test, quadruple test, and noninvasive prenatal tests (NIPT) between January 2016 and December 2020. Thirty percent (7,860/25,736) of pregnancies received prenatal screening tests for aneuploidies disorders, and 17.8% underwent prenatal diagnosis tests without screening. The highest percentage of screening tests was first-trimester test (64.5%). The high-risk results were 4% for first-trimester test, 6.6% for quadruple test, and 1.3% for NIPT. The serum screening tests for trisomy 13 and 18 had no true positives; therefore, we could not calculate sensitivity. For the first-trimester test, the sensitivity for trisomy 21 was 71.4% (95% confidence intervals (CI) 30.3-94.9); specificity for trisomy 13 and 18 was 99.9% (95% CI 99.8-99.9); and for trisomy 21 was 96.1% (95% CI 95.6-96.7). For the quadruple test, the specificity for trisomy 18 was 99.6% (95% CI 98.9-99.8), while the sensitivity and specificity for trisomy 21 were 50% (95% CI 26.7-97.3) and 93.9% (95% CI 92.2-95.3), respectively. NIPT had 100% sensitivity and specificity for trisomy 13, 18 and 21, and there were neither false negatives nor false positives. For pregnant women < 35 years, the prevalence of trisomy 13, 18, and 21 per 1,000 births was 0.28 (95% CI 0.12-0.67), 0.28 (95% CI 0.12-0.67), and 0.89 (95% CI 0.54-1.45), respectively. For pregnant women ≥35 years, the prevalence of trisomy 13, 18, and 21 per 1,000 births was 0.26 (95% CI 0.06-1.03), 2.59 (95% CI 1.67-4.01), and 7.25 (95% CI 5.58-9.41), respectively. For all pregnancies, the prevalence of trisomy 13, 18, and 21 per 1,000 births was 0.27 (95% CI 0.13-0.57), 0.97 (95% CI 0.66-1.44), 2.80 (95% CI 2.22-3.52), respectively., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Wongkrajang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: This study aims to evaluate the correlation combined fetal fraction and Z-score for fetal trisomies 13, 18, and 21 of NIPT by the semiconductor sequencing platform and further analyze the differences of different sequencing depths., Methods: A cohort of 61,581 pregnancies were recruited for NIPT. Invasive prenatal diagnostic confirmation is recommended in all high-risk NIPT cases. Logistic regression and rank correlation analysis were applied to analyze the relationship between different parameters. ROC curve analysis was adopted to analyze the cutoff values of Z-score and fetal fraction., Results: A total of 278 common trisomy pregnancies were verified in 377 NIPT-positive results. The fitted logistic regression models revealed that Z-scores of NIPT-positive results were significantly associated with PPVs (p < 0.05). The ROC curve analysis showed that the optimal cutoff value of Z-scores for T21, T18, and T13 was 7.597, 4.944, and 9.135 for NIPT and 9.489, 8.004, and 12.4 for NIPT-plus. If combing fetal fraction as another evaluation factor, the PPV of trisomy 21 gradually improved. We analyzed the correlation between the fetal fraction and the PPV, which revealed that the fetal fraction was significantly correlated with PPV. By analyzing the PPV of different groups divided by the associated criteria obtained from ROC curve, the PPV of high Z-score and high fetal fraction is higher in groups of Z-score > the optimal cutoff value., Conclusion: The results of this study show that the fetal fraction is significantly correlated with the PPV. Combining fetal fraction with Z-score is significantly better than in groups of Z-score-associated criteria; clinicians can give more accurate and efficient prenatal genetic counseling., (© 2023. The Author(s).)

Background: Omphalocele is associated with many aneuploidies, deletions and congenital anomalies. This study evaluates pregnancies diagnosed with omphalocele and its relevance to concomitant genetic disorders., Methods: The data of patients with the intrauterine diagnosis of omphalocele who had invasive diagnostic testing performed between January 2017 and January 2020 were evaluated retrospectively. The traditional karyotype analysis was performed to prenatal diagnosis for all fetuses. During the study period, all patients were scanned via ultrasonography by an experienced perinatologist, prenatally., Results: We evaluated 22 cases of omphalocele whose genetic testing results were available. The mean maternal age was 25 (18-41) years. The median gestational week at diagnosis was 13 (11-22). Invasive genetic testing revealed aneuploidy in 7 patients (31.8%), 2 with trisomy 13 (9.1%), and 5 with trisomy 18 (22.8%). There were 5 fetuses (22.7%) that had extracorporeal liver: 1 had trisomy 18 (20%), 1 had trisomy 13 (20%), and the other 3 fetuses had a normal karyotype (60%). Further, 14 (63.6%) pregnancies were terminated: 4 had trisomy 18 (28.6%), 1 had trisomy 13 (7.1%), and 9 of the terminated pregnancies (64.3%) had additional congenital anomalies. There were 4 infants who died (50%) born from 8 patients who decided to continue with their pregnancy. The omphalocele sac of 1 infant spontaneously regressed in the ensuing weeks of pregnancy who is now 1 year old., Conclusions: The chromosomal abnormalities presented in up to 31.8% of cases diagnosed with omphalocele. Moreover, for cases with normal genetic testing results, the propensity for additional structural defects was high and the prognosis remains poor. Counseling parents to consider their option of terminating the pregnancy is appropriate.

Background: Non-invasive prenatal testing (NIPT) using cell-free DNA (cfDNA) circulating in maternal blood provides a sensitive and specific screening technique for common fetal aneuploidies, but the high cost and workflow complexity of conventional methodologies limit its widespread implementation. A unique rolling circle amplification methodology reduces cost and complexity, providing a promising alternative for increased global accessibility as a first-tier test., Methods: In this clinical study, 8160 pregnant women were screened on the Vanadis system for trisomies 13, 18, and 21, and positive results were compared to clinical outcomes where available., Results: The Vanadis system yielded a 0.07% no-call rate, a 98% overall sensitivity, and a specificity of over 99% based on available outcomes., Conclusion: The Vanadis system provided a sensitive, specific, and cost-effective cfDNA assay for trisomies 13, 18, and 21, with good performance characteristics and low no-call rate, and it eliminated the need for either next-generation sequencing or polymerase chain reaction amplification., (© 2023 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objective: The diagnostic accuracy of cell-free fetal DNA in screening for rare autosomal trisomies is uncertain. We conducted a systematic review and meta-analysis aiming to determine the predictive value of cell-free DNA in screening for rare autosomal trisomies., Data Sources: PubMed, Embase, and Web of Science were searched from inception to January 2022., Study Eligibility Criteria: All studies that reported on the diagnostic accuracy of cell-free DNA in the detection of rare autosomal trisomies were included. Case series were included if they contained at least 10 cases with diagnostic test results or postnatal genetic testing., Methods: Study appraisal was completed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Statistical analysis was performed using random-effects meta-analysis of double-arcsine transformed proportions of confirmed results in the fetus out of the positive tests to obtain a pooled estimate of the positive predictive value., Results: The search identified 7553 studies, of which 1852 were duplicates. After screening 5701 titles and abstracts, 380 studies proceeded to the full-text screen; 206 articles were retrieved for data extraction, of which another 175 articles were excluded. A total of 31 studies, with a total of 1703 women were included for analysis. The pooled positive predictive value of cell-free DNA for the diagnosis of rare autosomal trisomies was 11.46% (95% confidence interval, 7.80-15.65). Statistical heterogeneity was high (I 2 =82%). Sensitivity analysis restricted to 5 studies at low risk of bias demonstrated a pooled positive predictive value of 9.13% (95% confidence interval, 2.49-18.76). There were insufficient data to provide accurate ascertainment of sensitivity and specificity because most studies only offered confirmatory tests to women with high-risk results., Conclusion: The positive predictive value of cell-free DNA in diagnosing rare autosomal trisomies is approximately 11%. Clinicians should provide this information when offering cell-free DNA for screening of conditions outside of common autosomal trisomies., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Non-Invasive Prenatal Screening (NIPS) is a useful screening method for common aneuploidies that can occur in pregnancies. It yields high sensitivities and specificities for the targeted conditions it tests for. Most commonly, these include Trisomies in chromosomes 21, 18, and 13, as well as aneuploidies in chromosomes X and Y. It does not, however, replace diagnostic testing. We review four cases seen by our institutions of patients who had NIPS performed with low-risk results and subsequently had fetuses affected with trisomy 18., Methods: All fetal samples were evaluated by level II anatomic ultrasound and tested on amniocytes or products of conception through karyotype or chromosomal microarray following low-risk NIPS., Results: None of the fetuses showed evidence of mosaicism and had features (both on ultrasound and postnatally) consistent with Trisomy 18. Postnatal fluorescence in situ hybridization performed on Formalin-Fixed Paraffin-Embedded tissue from 3 of the affected pregnancies' placentas identified mosaicism of trisomy 18., Discussion: We discuss the possible explanations for the discrepancy between NIPS results and fetal karyotype, including, but not limited to placental mosaicism, placental size, and limitations of NIPS as a screening test., (© 2022 John Wiley & Sons Ltd.)

Objective: Twins account for approximately 1 in 30 live births in the United States. However, there are limited clinical experience studies published in noninvasive prenatal testing (NIPT) for detecting aneuploidies in twins. This study reports the performance of an SNP-based NIPT in the largest cohort with known outcomes for high-risk aneuploidy results., Method: This is a retrospective analysis of 18,984 results from commercial single-nucleotide polymorphism (SNP)-based NIPT tests performed in twins between October 2, 2017 and December 31, 2019. Follow-up for all 211 high-risk cases was solicited., Results: Follow-up outcomes were obtained in 105 cases. Positive predictive values (PPVs) for high-risk results were 88.7% (63/71, 95% Confidence Interval [CI]: 79.0%-95.0%) for trisomy 21% and 72.7% (8/11, 95% CI: 39.0%-94.0%) for trisomy 18. The results were stratified into monozygotic (MZ) and dizygotic (DZ). The PPVs in MZ were 100% for both trisomy 21 (4/4, 95% CI: 40%-100%) and trisomy 18 (1/1, 95% CI: 2.5%-100%). No trisomy 13 cases were detected in the MZ group. The PPVs in DZ were 88.1% (59/67, 95% CI: 77.8%-94.7%), 70.0% (7/10, 95% CI: 34.8%-93.3%), and 66.7% (2/3, 95% CI: 9.4%-99.2%) for trisomy 21, trisomy 18, and trisomy 13, respectively., Conclusion: The performance of SNP-based NIPT in this large twin cohort was comparable to previously reported twin NIPT studies. SNP-based NIPT allows for zygosity-based PPV assessment., (© 2022 Natera. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Objective: To analyze the Z values of true and false positive cases by non-invasive prenatal testing (NIPT) in order to improve its accuracy in clinical practice., Methods: Results of 24 384 NIPT tests were reviewed. For cases with high risks for trisomies 21, 18 and 13, the range of Z values in true and false positive cases was analyzed and discussed., Results: A total of 335 high-risk cases were identified by NIPT, among which 256 had elected prenatal diagnosis, 153 (59.77%) were verified as true positives, and 103 (40.23%) were false positives, and the area under the curve (AUC) was 0.9994. For NIPT screening, the positive predictive value (PPV) for trisomy 21 was 100% when Z>13, regardless if the pregnant woman was over 35. When 335 and about 41.6% (5/12) for those<35. For trisomy 18, the PPV was 100% when Z>13, and only 14.3% (1/7) when 3

A vanishing twin (VT) occurs in up to 30% of early diagnosed twin pregnancies and is associated with an increased risk of fetal aneuploidy. Here, we describe our experience in a large VT population of 847 patients that underwent noninvasive prenatal testing (NIPT) for common fetal trisomies over a three-year period. All patients underwent an ultrasound examination prior to NIPT. Two comparison populations were included, namely, the singleton ( n = 105,560) and the viable multiple gestation pregnancy samples ( n = 9691) collected over the same period. All NIPT samples in the VT population received a result, of which 14 were high-risk for trisomy 21 (1.6%), nine for trisomy 18 (1.1%), and six for trisomy 13 (0.7%). Diagnostic testing confirmed the presence of trisomy 21 in 6/12 samples, giving a positive predictive value of 50%. One trisomy 18 case and no trisomy 13 cases were confirmed. The time between fetal demise and NIPT sampling did not appear to affect the number of true- or false-positive cases. In conclusion, NIPT is an effective screening method for trisomy 21 in the surviving fetus(es) in VT pregnancies. For trisomies 18 and 13, a positive NIPT should be interpreted carefully and ultrasound monitoring is preferrable over invasive diagnostic testing.

Objective: To investigate the influence of Z -score and different risk factors on positive predictive value (PPV) of noninvasive prenatal testing (NIPT) for chromosome aneuploidies. Methods: A total of 81 838 NIPT samples from January 1, 2016 to May 31, 2021 in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. Invasive prenatal diagnosis was applied to verify the diagnosis of NIPT-positive results and the corresponding PPV was calculated. The PPV of the samples with different Z -score were compared. The women were divided into high-risk group and non-high-risk group: high-risk group ( n =39 114) included those with ultrasound soft index abnormalities, advanced maternal age or high risk for maternal serum screening, while non-high-risk group ( n =42 724) included those with intermediate risk for maternal serum screening or no indications. The differences of the PPV between these two groups were compared. Finally, the comprehensive influence of Z -score and different risk factors on PPV were analyzed. Results: A total of 471 high-risk cases were detected by NIPT results, including 362 cases of trisomy 21, 77 cases of trisomy 18 and 32 cases of trisomy 13. For trisomy 21, trisomy 18 and trisomy 13, there were 226 cases, 46 cases and 6 cases which were confirmed via invasive prenatal diagnosis respectively. The corresponding PPV were 79.3% (226/285), 82.1% (46/56) and 27.3% (6/22), respectively. PPV of trisomy 21 and trisomy 18 were positively correlated with the corresponding Z -score ( r =0.92, 0.62, all P <0.05), while trisomy 13 could not be analyzed due to the small sample size. The PPV of high-risk group was 85.2% (207/243), which was higher than that of the non-high-risk group with PPV of 59.2%(71/120, χ 2 =30.30, P <0.01). When the Z -score was between 3-<4 and 4-<5, the PPV of the high-risk group were 46.2%(12/26)and 62.5%(15/24) respectively, which were higher than those of the non-high-risk group [16.0%(4/25) and 14.3%(3/21), χ 2 =4.10, 8.90, all P <0.05]. With the increase of Z -score, there was no significant difference in PPV between the two groups (all P >0.05). Conclusions: The PPV of trisomy 21 and trisomy 18 are positively correlated with Z -score. The PPV of high-risk group is higher than that of non-high-risk group. The combination of Z -score and other risk factors may provide more accurate genetic counseling for those with NIPT positive results.

A total of 15,267 pregnancies were tested by NIPT in this study. Grey zone (z score: 2.58 ∼ 4 and -4∼-2.58) was set for screening out aneuploidy 21, 18 and 13. Cases with z score located in the grey zone were retested starting from DNA extraction. The chi-squared test and/or the Fisher's exact test were used to compare variables. One hundred and eight screening-positive samples in the first run of NIPT were common trisomies 21 ( N  = 83), trisomies18 ( N  = 13) or trisomies 13 ( N  = 12), with PPVs of 87.18%, 76.92%, and 30% respectively. For the cases in the grey zone, most of them (67.15%, 184/274) were reported with Z score of Chromosome 21 in the grey zone and 176 were reclassified as negative by the second run of NIPT; while 3 cases reclassified as trisomy 21 and 1 case reclassified as trisomy 13 were finally confirmed by karyotyping analysis, with PPV 25% and 20% respectively. The grey zone and the second run of NIPT in this study showed that the grey zone and second run NIPT approach was able to accurately help categorise cases as negative and positive. Invasive diagnosis is recommended to prevent false negative aneuploidies for samples located in the special z score scope of 2.58-3 for two runs of NIPT. IMPACT STATEMENT What is already known on this subject? Grey zone was widely used in NIPT. The performance of grey zone of clinical samples on Illumina HiSeq 2000 instrument has been reported, and the performance of grey zone on some mainstream sequencers with simulated samples has also been summarised. Reported treatments for samples located in the grey zone in NIPT usually included being classified into 'unclassified' or 'no call' followed by following up and/or karyotyping analysis. What do the results of this study add? This study investigated the performance of the grey zone on Ion Proton DA8600 with clinical samples; and it present an alternative treatment for samples in grey zone that reclassified them as negative or positive by the second run of sequencing. What are the implications of these findings for clinical practice and/or further research? Our own data for the performance of the grey zone in the cfDNA assay on the semiconductor sequencing platform might provide raw materials for other researchers' meta-analysis, cohort study, or other studies. Details of Z score distributions of chromosomes in grey zone, results of the second run of NIPT for samples in the grey zone, and false negative samples in the grey zone would help lab technicians better analyse the NIPT results and help doctors to improve genetic counselling.

Background: Cell-free DNA noninvasive prenatal screening for trisomies 21, 18, and 13 has been rapidly adopted into clinical practice. However, previous studies are limited by a lack of follow-up genetic testing to confirm the outcomes and accurately assess test performance, particularly in women at a low risk for aneuploidy., Objective: To measure and compare the performance of cell-free DNA screening for trisomies 21, 18, and 13 between women at a low and high risk for aneuploidy in a large, prospective cohort with genetic confirmation of results STUDY DESIGN: This was a multicenter prospective observational study at 21 centers in 6 countries. Women who had single-nucleotide-polymorphism-based cell-free DNA screening for trisomies 21, 18, and 13 were enrolled. Genetic confirmation was obtained from prenatal or newborn DNA samples. The test performance and test failure (no-call) rates were assessed for the cohort, and women with low and high previous risks for aneuploidy were compared. An updated cell-free DNA algorithm blinded to the pregnancy outcome was also assessed., Results: A total of 20,194 women were enrolled at a median gestational age of 12.6 weeks (interquartile range, 11.6-13.9). The genetic outcomes were confirmed in 17,851 cases (88.4%): 13,043 (73.1%) low-risk and 4808 (26.9%) high-risk cases for aneuploidy. Overall, 133 trisomies were diagnosed (100 trisomy 21; 18 trisomy 18; 15 trisomy 13). The cell-free DNA screen positive rate was lower in the low-risk vs the high-risk group (0.27% vs 2.2%; P<.0001). The sensitivity and specificity were similar between the groups. The positive predictive value for the low- and high-risk groups was 85.7% vs 97.5%; P=.058 for trisomy 21; 50.0% vs 81.3%; P=.283 for trisomy 18; and 62.5% vs 83.3; P=.58 for trisomy 13, respectively. Overall, 602 (3.4%) patients had no-call result after the first draw and 287 (1.61%) after including cases with a second draw. The trisomy rate was higher in the 287 cases with no-call results than patients with a result on a first draw (2.8% vs 0.7%; P=.001). The updated algorithm showed similar sensitivity and specificity to the study algorithm with a lower no-call rate., Conclusion: In women at a low risk for aneuploidy, single-nucleotide-polymorphism-based cell-free DNA has high sensitivity and specificity, positive predictive value of 85.7% for trisomy 21 and 74.3% for the 3 common trisomies. Patients who receive a no-call result are at an increased risk of aneuploidy and require additional investigation., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background Among the many malformations associated with trisomy 13, one of the less recognized is dinosaur tail appendix. Case report: We illustrate a dinosaur-tail appendix from an autopsy in a newborn female with trisomy 13. This malformation has a frequency between 0.014% and 3.7% in general population. Conclusion: Trisomy 13 is a relatively well-known chromosomal disorder in which dinosaur tail appendix can be found. This entity should be considered element of a complete morphological diagnosis.

Purpose: Noninvasive prenatal screening (NIPS) using cell-free DNA has been assimilated into prenatal care. Prior studies examined clinical validity and technical performance in high-risk populations. This systematic evidence review evaluates NIPS performance in a general-risk population., Methods: Medline (PubMed) and Embase were used to identify studies examining detection of Down syndrome (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies, rare autosomal trisomies, copy number variants, and maternal conditions, as well as studies assessing the psychological impact of NIPS and the rate of subsequent diagnostic testing. Random-effects meta-analyses were used to calculate pooled estimates of NIPS performance (P < .05). Heterogeneity was investigated through subgroup analyses. Risk of bias was assessed., Results: A total of 87 studies met inclusion criteria. Diagnostic odds ratios were significant (P < .0001) for T21, T18, and T13 for singleton and twin pregnancies. NIPS was accurate (≥99.78%) in detecting sex chromosome aneuploidies. Performance for rare autosomal trisomies and copy number variants was variable. Use of NIPS reduced diagnostic tests by 31% to 79%. Conclusions regarding psychosocial outcomes could not be drawn owing to lack of data. Identification of maternal conditions was rare., Conclusion: NIPS is a highly accurate screening method for T21, T18, and T13 in both singleton and twin pregnancies., Competing Interests: Conflict of Interest N.C.R. is a consultant for The Jackson Laboratories and the ObG Project. E.S.B. and M.L.L. serve as directors in, and D.L. is employed by, clinical laboratories that perform a breadth of genetic and genomic analyses on a fee-for-service basis. All other authors declare no conflicts of interest., (Copyright © 2022 American College of Medical Genetics and Genomics. Published by Elsevier Inc. All rights reserved.)

The effects of medical and surgical interventions on the survival of patients with trisomy 18 have been reported, leading to changes in perinatal management and decision-making. However, few studies have fully reported the recent changes in survival and treatment of trisomy 18. We examined how treatment and survival of patients with trisomy 18 have changed over a decade in a Japanese pediatric tertiary referral center. This retrospective cohort study included patients with trisomy 18 who were admitted within the first 7 days of life at the Hyogo Prefectural Kobe Children's Hospital between 2008 and 2017. The patients were divided into early period (EP) and late period (LP) groups based on the birth year of 2008-2012 and 2013-2017, respectively. Changes in treatment and survival rates were compared between the two groups. A total of 56 patients were studied (29 in the EP group and 27 in the LP group). One-year survival rates were 34.5% and 59.3% in the EP and LP groups, respectively. The survival to discharge rate significantly increased from 27.6% in the EP group to 81.5% in the LP group (p < 0.001). The proportion of patients receiving surgery, especially for congenital heart defects, significantly increased from 59% in the EP group to 96% in the LP group (p = 0.001). In our single-center study, survival and survival to discharge were significantly improved in patients with trisomy 18, probably because of increased rate of surgical interventions. These findings may facilitate better decision-making by patients' families and healthcare providers., (© 2021 Wiley Periodicals LLC.)

Objectives: To evaluate the failure rate and performance of cell-free DNA (cfDNA) testing as a first-line screening method for major trisomies, performed by two laboratories using different analytical methods: a targeted chromosome-selective method (Harmony ® prenatal Test) versus a home-brew genome-wide (GW) massively parallel sequencing method (HB-cfDNA test), and to evaluate the clinical value of incidental findings for the latter method., Methods: CfDNA testing was performed in 3137 pregnancies with the Harmony ® prenatal Test and in 3373 pregnancies with the HB-cfDNA test. Propensity score analysis was used to match women between both groups for maternal age, weight, gestational age at testing, in vitro fertilization, rate of twin pregnancies and that of aneuploidies. Detection rates for trisomy 21 were compared between the 2 laboratories. For the HB-cfDNA test, cases with rare incidental findings were reported, including their clinical follow-up., Results: The Harmony ® prenatal Test failed at the first attempt in 90 (2.9%) of 3114 women and the HB-cfDNA test in 413 (12.2%) of 3373 women. Postmatched comparisons of the women's characteristics indicate a significantly lower failure rate in the Harmony ® group (2.8%) than in the HB cfDNA group (12.4%; p  < .001). Of the 90 women in whom the Harmony ® prenatal Test failed, 61 had a repeat test, which still failed in 10, and of the 413 women in whom the HB-cfDNA test failed, 379 had a repeat test, which still failed in 110. The total failure rate after one or two attempts was therefore 1.3% (39/3114) for Harmony ® and 4.3% (144/3373) for the HB cfDNA test. After the first or second Harmony ® prenatal Test, a high-risk result was noted in 17 of the 17 cases with trisomy 21, in 5 of the seven cases with trisomy 18, and a no-call in two cases, and in the one case with trisomy 13. The respective numbers for the HB-cfDNA test are 17 of the 18 cases with trisomy 21, and a no-call in one case, 2 of the two cases with trisomy 18, and in 2 of the three cases with trisomy 13, and a no-call in one. Of the 3373 women with the HB-cfDNA test, a rare incidental finding was noted in 28 (0.8%) of the cases, of which only 2 were confirmed on amniocytes (one with microduplication 1q21.1q21.2 and one with a deletion Xp21.1), and in another case a deletion rather than a duplication of the long arm of chromosome 8 was found. In all 28 cases, there was normal clinical follow-up., Conclusions: Comparison of cfDNA testing between these two laboratories showed a four-fold lower failure rate with the Harmony ® prenatal Test, with a similar detection rate for trisomy 21. We showed no clinical relevance of disclosing additional findings beyond common trisomies with the GW HB-cfDNA test.

Background: Trisomy 13 or Patau syndrome has a prevalence of 1:10,000-20,000 and is characterized by microcephaly, microphthalmia, polydactyly, as well as other dysmorphic features and malformations, with a patient survival of 13% in the first year. Trisomy 13 presents either as a free chromosome 13 trisomy or associated with a chromosomal Robertsonian translocation, as partial trisomy affecting proximal or distal 13q regions, and also as a mosaic. Mosaic trisomy 13 shows a highly variable phenotype, displaying from mild to severe affectations. We present a 12-year-old Mexican female patient with intellectual disability, dysmorphic features, polymenorrhea, and long survival, whose initial cytogenetic study referred to a small supernumerary marker chromosome., Methods: GTG banding karyotype, high-resolution chromosomal microarray, and fluorescent in situ hybridization analyses were performed in peripheral blood cells., Results: Our analyses demonstrated a de novo mosaicism in our patient, constituted by proximal trisomy 13q10-q14.3 (82%) and free trisomy 13 (18%) cell lines. Her final chromosomal complement is mos 47,XX,+del(13)(q14.3)[25]/47,XX,+13[7].ish del(13)(RB1+)[17]/13q14(RB1x3)[2].arr[GRCh37] 13q11q14.3(19436286&#95;51726415)x3,13q11q34(19436286&#95;115107733)x2-3 dn., Conclusions: The wide spectrum of clinical manifestations observed in our patient mainly results from the proximal trisomy 13q, and her phenotype is modified by the presence of a free trisomy 13 cell line. We propose that her mosaicism probably derived from a trisomic zygote that underwent a failed trisomic rescue associated with chromothripsis, originating the cell line with partial 13q proximal trisomy, whose selective advantage could explain the long survival of our patient., (© 2021 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Background: Rolling-circle replication (RCR) is a novel technology that has not been applied to cell-free DNA (cfDNA) testing until recently. Given the cost and simplicity advantages of this technology compared to other platforms currently used in cfDNA analysis, an assessment of RCR in clinical laboratories was performed. Here, we present the first validation study from clinical laboratories utilizing RCR technology. Methods : 831 samples from spontaneously pregnant women carrying a singleton fetus, and 25 synthetic samples, were analyzed for the fetal risk of trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13), by three laboratories on three continents. All the screen-positive pregnancies were provided post-test genetic counseling and confirmatory diagnostic invasive testing (e.g., amniocentesis). The screen-negative pregnancies were routinely evaluated at birth for fetal aneuploidies, using newborn examinations, and any suspected aneuploidies would have been offered diagnostic testing or confirmed with karyotyping. Results : The study found rolling-circle replication to be a highly viable technology for the clinical assessment of fetal aneuploidies, with 100% sensitivity for T21 (95% CI: 82.35-100.00%); 100.00% sensitivity for T18 (71.51-100.00%); and 100.00% sensitivity for T13 analyses (66.37-100.00%). The specificities were >99% for each trisomy (99.7% (99.01-99.97%) for T21; 99.5% (98.62-99.85%) for T18; 99.7% (99.03-99.97%) for T13), along with a first-pass no-call rate of 0.93%. Conclusions : The study showed that using a rolling-circle replication-based cfDNA system for the evaluation of the common aneuploidies would provide greater accuracy and clinical utility compared to conventional biochemical screening, and it would provide comparable results to other reported cfDNA methodologies.

Objective: To explore the value of chromosomal microarray analysis (CMA) for the diagnosis of fetuses with high risk signaled by non-invasive prenatal testing (NIPT)., Methods: From June 2017 to August 2019, 628 pregnant women with high risk signaled by NIPT underwent invasive prenatal diagnosis. Amniotic fluid or cord blood samples were subjected to chromosomal karyotyping analysis or CMA. Pregnancy outcome and postnatal conditions of the fetuses were followed up., Results: The positive predictive value for trisomy 21, trisomy 18, trisomy 13, sex chromosome aneuploidy, other rare trisomies and copy number variants (CNVs) among the 628 women were 86.4% (127/147), 41.7% (30/72), 12.9% (4/31), 43.7% (101/231), 16.5% (14/85) and 52.2% (35/67), respectively. In 218 samples with normal karyotype, 5.5% (12/218) of additional pathogenic CNVs and 2.3% (5/218) of loss of heterozygosity were detected by CMA., Conclusion: CMA combined with karyotyping analysis can be used as first-tier test for prenatal diagnosis for women with high-risk signaled by NIPT.

Clinical histories and outcome data of long-term survivors with trisomy 13 are rare. The goal of this study was to collect the medical histories of adult individuals (≥18 years old) with apparent non-mosaic trisomy 13/Patau syndrome to help gain further insight in to the clinical course for individuals with this condition and to characterize the manifestations for surveillance and management. We collected 11 families through a contact person with the LWT13 (Living with Trisomy 13) LIFE support group. We performed telephone interviews to gather their medical histories and report these data in system-based summaries, tables, and clinical vignettes. In instances where parents retained copies of genetic testing reports or clinicians currently taking care of the individual with trisomy 13 were able to provide documentation, we confirmed diagnosis. All clinical histories and reported manifestations were consistent with a diagnosis of trisomy 13. We also elicited comments from parents on their personal experiences of raising an individual with trisomy 13., (© 2021 Wiley Periodicals LLC.)

Background: Clinical studies suggest the importance of genetic components in the etiology of keratoconus. However, the contributing genes and variants remain elusive. We present a case of bilateral keratoconus in a child with partial trisomy 13, with a trisomic region spanning loci that have been associated with keratoconus. Materials and Methods: This is a single, retrospective case report of a child with a molecular diagnosis of partial trisomy 13, who was diagnosed with bilateral keratoconus for which at the age of 11 years, she underwent successive epithelium-off corneal cross-linking (CXL) procedures in both eyes, followed by temporary central tarsorrhaphy under general anesthesia. Results: Patient's molecular diagnosis was 70 Megabase trisomic region 13q14.11q34. Pre CXL pachymetry was 426 μm and 496 μm, maximum K values were 52.28 D and 55.45 D in right and left eyes, respectively; at last follow up (12 months post-op) these were 494 μm and 509 μm for pachymetry and maximum K values 50.50 D and 52.43 D in the right and left eyes, respectively. No signs of progression were detected. Conclusion: To the best of our knowledge, this is the first case report to document bilateral keratoconus in a child with partial trisomy 13, in whom successful epithelium-off CXL was achieved with general anesthesia. We emphasize the importance of screening, early diagnosis, and therapy of this treatable but rare cause of decreased vision in partial trisomy 13 patients.

Few population-based studies have analyzed patterns of co-occurring birth defects among those with trisomy 13. We evaluated the frequency of all possible combinations of any one, two, three, or four additional co-occurring birth defects among 736 individuals with trisomy 13 using data from the Texas Birth Defects Registry for deliveries during 1999-2014. We calculated the observed-to-expected ratio for each combination, adjusting for the known tendency for birth defects to cluster non-specifically. To address potential ascertainment differences among live births and non-live births, we repeated analyses specifically among live births. The combination of defects with the largest observed-to-expected ratio was microcephalus, reduction deformities of brain (e.g., holoprosencephaly), anomalies of nose, and polydactyly. As expected, most of the highest 30 observed-to-expected ratios involved combinations with documented features of trisomy 13, including defects of the scalp (e.g., aplasia cutis) and heart. Results were similar among sensitivity analyses restricted to live births. Our findings may help further delineate the phenotypic spectrum for trisomy 13 and may inform future research related to improving screening and counseling for the condition., (© 2021 Wiley Periodicals LLC.)

Trisomy 13 is one of the three most common aneuploidy syndromes in live-born infants. It is associated with mortality rates as high as 90% within the first year of life, in large part, due to the high prevalence of severe congenital abnormalities that increase mortality and morbidity. However, life-saving and life-prolonging medical interventions are being performed at a higher rate for these infants, resulting in increased rates of survival. Although cardiac complications have been well described in infants with trisomy 13, these patients also experience other complications such as respiratory, neurological, genitourinary, abdominal, otolaryngologic, and orthopedic complications that can impact their quality of life. The goal of this review is to present a comprehensive description of complications in children with trisomy 13 to aid in the development of monitoring and treatment guidelines for the increasing number of providers who will be caring for these patients throughout their lives. Where the evidence is available, this review presents screening recommendations to allow for more rapid detection and documentation of these complications., (© 2021 Wiley Periodicals LLC.)

A female cynomolgus monkey (Macaca fascicularis) with facial features characteristic of Down syndrome showed abnormal behavior, unwariness toward humans, and poor concentration. The number of metaphase chromosomes in blood lymphocytes was examined and found to be 43, which indicated one extra chromosome to the normal diploid number (2n = 42). We then used Q-banding and multicolor FISH techniques to identify the extra chromosome. The results revealed an additional chromosome 17, with no other chromosomal rearrangements, such as translocations. Since no mosaicism or heterozygous variant chromosomes were observed, full trisomy 17 was assessed in this female cynomolgus monkey. Chromosome 17 corresponds to human chromosome 13, and human trisomy 13, known as Patau syndrome, results in severe clinical signs and, often, a short life span; however, this individual has reached an age of 10 years with only mild clinical signs. Although genomic differences exist between human and macaques, this individual's case could help to reveal the pathological and genetic mechanisms of Patau syndrome., (The Author(s). Published by S. Karger AG, Basel.)