BACKGROUND: Digital Polymerase Chain Reaction (dPCR) presents a promising approach for quantifying DNA and analyzing copy number variants, particularly in non-invasive prenatal testing. This method offers a streamlined and time-efficient procedure in contrast to the widely used next-generation sequencing for non-invasive prenatal testing. Studies have reported encouraging results for dPCR in detecting fetal autosomal aneuploidies. Consequently, this systematic review aimed to evaluate the effectiveness of dPCR in screening for trisomy 21, 18, and 13.
METHODS: A systematic search was conducted in PubMed, Web of Sciences, and Embase for relevant articles published up to December 30, 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was utilized for the quality assessment of the included articles. Furthermore, a bivariate random-effect regression model was used to conduct a meta-analysis on the utility of dPCR for trisomy 21 screening.
RESULTS: A total of 9 articles were included in this review, with all of them assessing the utility of dPCR in trisomy 21 screening, and 2 and 1 studies conducting additional analysis on the screening abilities of dPCR for trisomy 18 and 13, respectively. A bivariate random-effects model calculated pooled sensitivity and specificity with a 95% confidence interval (CI). Meta-analysis of 6 studies comparing trisomy-21 screening with karyotyping demonstrated dPCR\'s pooled sensitivity of 98% [95% CI: 94 -100] and specificity of 99% [95% CI: 99 -100]. While conducting a meta-analysis for trisomy 13 and 18 proved impractical, reported values for sensitivity and specificity were favorable.
CONCLUSIONS: These findings suggest that dPCR holds promise as an effective tool for non-invasive prenatal testing, presenting a less time-consuming and intricate alternative to next-generation sequencing. However, further research is necessary to evaluate dPCR\'s applicability in clinical settings and to delineate its specific advantages over next-generation sequencing. This study contributes valuable insights into the potential of dPCR for enhancing prenatal screening methodologies.
BACKGROUND: The protocol of this study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) on 7/3/2024, with a registration code of CRD42024517523.

OBJECTIVE: Trisomy 18 and trisomy 13 are the most common autosomal trisomies following trisomy 21, with overall incidence rising. Both diagnoses are characterized by multisystem involvement and were previously thought to be incompatible with life. New data suggest that prolonged survival is possible, and thus many families are opting for more aggressive medical interventions. This study aims to describe airway findings in trisomy 18 and trisomy 13, as these have not been comprehensively studied and can impact medical decision-making. We hypothesize that most children with trisomy 18 and trisomy 13 will have abnormal findings on airway endoscopy.
METHODS: This a 10-year retrospective analysis of children with trisomy 13 or trisomy 18 who underwent endoscopic airway evaluation at a single center between 2011 and 2021. A total of 31 patients were evaluated.
RESULTS: Thirty-one patients were included and underwent flexible bronchoscopy by a pediatric pulmonologist, often in conjunction with rigid bronchoscopy performed by pediatric otolaryngology. Findings were typically complimentary. All patients had at least one clinically significant finding on evaluation, and most patients had both upper and lower airway, as well as static and dynamic airway findings. The most common airway findings in children with trisomy 13 and 18 include tracheomalacia, bronchomalacia, laryngomalacia, hypopharyngeal collapse, glossoptosis, and bronchial compression.
CONCLUSIONS: These findings can have significant implications for clinical care, and thus knowledge of trends has the potential to improve counseling on expected clinical course, presurgical planning, and informed consent before interventions.

Most frequent chromosomal syndromes like Down, Patau, Edwards, Turner, and Williams affect the pediatric population in various ways, and congenital heart disease explains the altered quality of life they suffer. There is a lack of studies reviewing the cardiac anomalies in these syndromes, and the ones that exist are publications from past decades. We reviewed databases such as MEDLINE, LILACS, SCIELO, and Google Scholar, selecting the best possible evidence, and each chromosomal syndrome was investigated in relation to congenital heart disease, constituting five search groups. The article shows the characteristics of each heart disease described in the studies reviewed, the author, date of publication, country, and population studied, as well as a brief description of the frequency of the disease and its mortality. The results described in this review were contrasted with previous existing literature to verify if there was correspondence between the reported frequencies. The most frequent congenital heart diseases were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), atrial septal defect (ASD), and persistent ductus arteriosus (PDA) in Down syndrome patients, PDA, ASD, and VSD in Patau syndrome patients, AVSD, PDA and valvular defects in Edwards syndrome, bicuspid aortic valve, aortic coarctation and aortic stenosis in Turner syndrome, and supravalvular aortic stenosis and pulmonary stenosis in Williams syndrome.

The screening performance of non-invasive prenatal testing (NIPT) in vanishing twin (VT) pregnancies is relatively unknown. To close this knowledge gap, we conducted a systematic review of the available literature. Studies describing the test performance of NIPT for trisomy 21, 18, 13, sex chromosomes and additional findings in pregnancies with a VT were retrieved from a literature search with a publication date until October 4, 2022. The methodological quality of the studies was assessed with the quality assessment tool for diagnostic accuracy studies-2 (QUADAS-2). The screen positive rate of the pooled data and the pooled positive predictive value (PPV) were calculated using a random effects model. Seven studies, with cohort sizes ranging from 5 to 767, were included. The screen positive rate of the pooled data for trisomy 21 was 35/1592 (2.2%), with a PPV of 20% (confirmation in 7/35 cases [95% CI 9.8%-36%]). For trisomy 18, the screen positive rate was 13/1592 (0.91%) and the pooled PPV 25% [95% CI 1.3%-90%]. The screen positive rate for trisomy 13 was 7/1592 (0.44%) and confirmed in 0/7 cases (pooled PPV 0% [95% CI 0%-100%]). The screen positive rate for additional findings was 23/767 (2.9%), of which none could be confirmed. No discordant negative results were reported. There is insufficient data to fully evaluate NIPT performance in pregnancies with a VT. However, existing studies suggest that NIPT can successfully detect common autosomal aneuploidies in pregnancies affected by a VT but with a higher false positive rate. Further studies are needed to determine the optimal timing of NIPT in VT pregnancies.

To perform a systematic review and meta-analysis of the available literature on low fetal fraction (LFF) in cell-free DNA (cfDNA) screening and the risk of fetal chromosomal aberrations.
We searched articles published between January 2010 and May 2021 in PubMed and EMBASE databases. Risk of bias was assessed using QUADAS-2.
Twenty-seven studies met the inclusion criteria, comprising data of 243,700 singleton pregnancies. Compared to normal fetal fraction, LFF was associated with a higher risk of trisomy 13 (OR 5.99 [3.61-9.95], I 2 of heterogeneity = 0%, n = 22 studies), trisomy 18 (OR 4.46 [3.07-6.47], I 2  = 0%, n = 22 studies), monosomy X (OR 5.88 [2.34-14.78], I 2  = 18%, n = 10 studies), and triploidy (OR 36.39 [9.83-134.68], I 2  = 61%, n = 6 studies), but not trisomy 21 (OR 1.25 [0.76-2.03], I 2  = 36%, n = 23 studies). LFF was also associated with a higher risk of various other types of fetal chromosomal aberrations (OR 4.00 [1.78-9.00], I 2  = 2%, n = 11 studies). Meta-analysis of proportions showed that absolute rates of fetal chromosomal aberrations ranged between 1% and 2% in women with LFF. A limitation of this review is the potential risk of ascertainment bias because of differences in outcome assessment between pregnancies with LFF and those with normal fetal fraction. Heterogeneity in population characteristics or applied technologies across included studies may not have been fully addressed.
An LFF test result in cfDNA screening is associated with an increased risk of fetal trisomy 13, trisomy 18, monosomy X, and triploidy, but not trisomy 21. Further research is needed to assess the association between LFF and other specific types of fetal chromosomal aberrations.

BACKGROUND: Trisomy 18 syndrome, also called Edwards syndrome, is the second most common autosomal trisomy after trisomy 21 that is caused by the presence of an extra copy of chromosome 18. Approximately 50% of infants with trisomy 18 cannot survive for more than 1 week and about 5 - 10% of children die within 1 year after birth. The aim of this study is to describe a 4-year-old female patient of mosaic trisomy 18 with normal prenatal ultrasound findings and maternal serum markers and to investigate the relationship between the percentage of trisomic cells and the major clinical phenotypes combined with other nine patients through a review of the literature.
METHODS: The patient\'s peripheral blood was examined by cytogenetic G-banding technique.
RESULTS: The cytogenetics results reported following the ISCN 2020 guideline as mos 47,XX,+18[87]/46,XX[13].
CONCLUSIONS: There is little correlation between various phenotypes of mosaic trisomy 18 and the percentage of trisomy cells in the patient\'s peripheral leukocytes. Although most of fetuses with mosaic trisomy 18 have abnormal ultrasound findings, it is necessary to highlight the possibility of normal findings during the pregnancy.

BACKGROUND: Patients with Trisomy 13(T13) and 18(T18) have many comorbidities that may require surgical intervention. However, surgical care and outcomes are not well described, making patient selection and family counseling difficult. Here the surgical history and outcomes of T13/ T18 patients are explored.
METHODS: A retrospective review of patients with T13 or T18 born between 1990 and 2020 and cared for at a tertiary children\'s hospital (Riley Hospital for Children, Indianapolis IN) was conducted, excluding those with insufficient records. Primary outcomes of interest were rates of mortality overall and after surgery. Factors that could predict mortality outcomes were also assessed.
RESULTS: One-hundred-seventeen patients were included, with 65% T18 and 35% T13. More than half of patients(65%) had four or more comorbidities. Most deaths occurred by three months at median 42.0 days. Variants of classic trisomies (mosaicism, translocation, partial duplication; p = 0.001), higher birth weight(p = 0.002), and higher gestational age(p = 0.01) were associated with lower overall mortality, while cardiac(p = 0.002) disease was associated with higher mortality. Over half(n = 64) underwent surgery at median age 65 days at time of first procedure. The most common surgical procedures were general surgical. Median survival times were longer in surgical rather than nonsurgical patients(p<0.001). Variant trisomy genetics(p = 0.002) was associated with lower mortality after surgery, while general surgical comorbidities(p = 0.02), particularly tracheoesophageal fistula/esophageal atresia(p = 0.02), were associated with increased mortality after surgery.
CONCLUSIONS: Trisomy 13 and 18 patients have vast surgical needs. Variant trisomy was associated with lower mortality after surgery while general surgical comorbidities were associated with increased mortality after surgery. Those who survived to undergo surgery survived longer overall.
METHODS: III.

Trisomy 18 (Edward syndrome) was first described by Edwards et al. in 1960. The condition is the second most common autosomal trisomy syndrome in males. The prevalence in infants is estimated as 1/6000-1/8000. Those affected have a high mortality rate - only 4% may survive their first year.

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.
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.
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.
NIPS is a highly accurate screening method for T21, T18, and T13 in both singleton and twin pregnancies.

Trisomy 18 is a chromosomal disease, caused by the presence of a supernumerary chromosome 18. Mortality among infants with trisomy 18 is high, secondary to lethal malformations associated with this syndrome. The purpose of this study was to describe the clinical and cytogenetic features of these patients, as well as the role of genetic counselling. We conducted a cross-sectional descriptive study over a 5-year period, from July 2015 to April 2019. The study involved, patients followed up in the Department of Medical Genetics at the University Hospital Center Ibn Rochd of Casablanca, having abnormalities suggestive of trisomy 18, then confirmed by cytogenetic study. The study enrolled 5 patients, 3 girls and 2 boys (female predominance; sex-ratio = 0,67) with clinically suspected Edward\'s syndrome, then confirmed by cytogenetic study. The mean age at diagnosis was 37.40 ± 23.98 days (9 days-2 months). Trisomy 18 was clinically suspected in two cases based on facial dysmorphism and malformative syndrome, a recognizable pattern of chromosomal abnormality. Two patients were hospitalized in the intensive care unit for decompensated heart failure associated with congenital heart disease, while one patient had neonatal respiratory distress associated with polymalformative syndrome at diagnosis. Cytogenetic study confirmed the diagnosis of free and homogeneous trisomy 18 in five patients, then genetic counselling was performed. The prevalence of trisomy 18 is variable. Global prevalence is estimated at 1/6000 live births, females are mostly affected. The diagnosis of trisomy 18 should be suspected at birth in newborns with typical craniofacial dysmorphism, arms lifted in supplication and permanent flexion of the fingers, the index finger overlapping the 3rd finger, the little finger overlapping the 4th finger. There are several malformations associated with trisomy 18. This syndrome should be also suspected in the antenatal period in patients with abnormalities on obstetric ultrasound. Moreover, survival is low and only one in 10 newborns reach the first year of life.