Cases Of Aneuploidy Research Articles

DNA Sequencing versus Standard Prenatal Aneuploidy Screening

BackgroundIn high-risk pregnant women, noninvasive prenatal testing with the use of massively parallel sequencing of maternal plasma cell-free DNA (cfDNA testing) accurately detects fetal autosomal aneuploidy. Its performance in low-risk women is unclear.MethodsAt 21 centers in the United States, we collected blood samples from women with singleton pregnancies who were undergoing standard aneuploidy screening (serum biochemical assays with or without nuchal translucency measurement). We performed massively parallel sequencing in a blinded fashion to determine the chromosome dosage for each sample. The primary end point was a comparison of the false positive rates of detection of fetal trisomies 21 and 18 with the use of standard screening and cfDNA testing. Birth outcomes or karyotypes were the reference standard.ResultsThe primary series included 1914 women (mean age, 29.6 years) with an eligible sample, a singleton fetus without aneuploidy, results from cfDNA testing, and a risk classification based on standard screening. For trisomies 21 and 18, the false positive rates with cfDNA testing were significantly lower than those with standard screening (0.3% vs. 3.6% for trisomy 21, P<0.001; and 0.2% vs. 0.6% for trisomy 18, P=0.03). The use of cfDNA testing detected all cases of aneuploidy (5 for trisomy 21, 2 for trisomy 18, and 1 for trisomy 13; negative predictive value, 100% [95% confidence interval, 99.8 to 100]). The positive predictive values for cfDNA testing versus standard screening were 45.5% versus 4.2% for trisomy 21 and 40.0% versus 8.3% for trisomy 18.ConclusionsIn a general obstetrical population, prenatal testing with the use of cfDNA had significantly lower false positive rates and higher positive predictive values for detection of trisomies 21 and 18 than standard screening. (Funded by Illumina; ClinicalTrials.gov number, NCT01663350.)

Genetic testing using array comparative genomic hybridization may benefit newborns with congenital heart disease

rray comparative genomic hybrid-ization (aCGH) should be offered as a first-tier genetic test in seriously ill newborns with congenital heart disease (CHD), according to a recent study.CHD is a birth defect that affects nearly 1% of live births and is frequently identified in surveillance programs [Reller et al., 2008]. Genetic factors often cause CHD, but newborns and older children with the condition who could benefit from genetic testing do not always receive it [Connor et al., 2013]. For patients with CHD in cardiac intensive care units (CICUs) who do, aCGH is preferable to chromosome analysis because it can detect more potential genetic causes, write researchers at the University of Pittsburgh in Pennsylvania [Bachman et al., 2013].In their study, Bachman and colleagues found that aCGH detected disease-causing mutations in 26.2% of 45 newborns with CHD admitted to the hospital’s CICU, while chromosome analysis found such mutations in just 9.4%, a difference of 22%. Additionally, aCGH testing detected 10 copy number variants that chromosome analysis did not.“Comparative genomic hybrid-ization has become our standard of care for babies with heart defects admitted to CICU,” says senior author Suneeta Madan-Khetarpal, Associate Professor of Pediatrics at the University of Pittsburgh School of Medicine.

First‐trimester assessment of nasal bone using retronasal triangle view: a prospective study

To examine the feasibility and accuracy of fetal nasal bone (NB) assessment in the retronasal triangle (RNT) view for aneuploidy screening in the first trimester of pregnancy. Consecutive women with singleton pregnancies undergoing sonographic screening at 11-13 weeks' gestation were prospectively evaluated. In all cases, assessment of the NB by using the RNT view was attempted and classified as present (if one or both of the NBs were clearly seen) or absent/hypoplastic (if the NB was not visualized or if it was small and less echogenic than the surrounding bones). The detection rate of fetal karyotypic abnormalities by the assessment of the NB in the RNT view was calculated. In total, 1977 women were scanned. The RNT was successfully examined in 1970 fetuses (99.6%). Fetal outcome was available in 1767 (89.7%) of evaluated cases, and of these, 39 (2.2%) cases of aneuploidy were documented (trisomy 21, n=17; trisomy 18, n=8; trisomy 13, n=5; Turner syndrome, n=5; and triploidy, n=4). The prevalence of absent/hypoplastic NB was 12/1728 (0.7%) in chromosomally normal fetuses and 12/17 (70.6%) in trisomy 21 fetuses. Sensitivity, specificity and positive and negative predictive values of absent/hypoplastic NB for trisomy 21 were 70.6%, 99.3%, 50.0% and 99.7%, respectively. The positive and negative likelihood ratios of NB assessment were 101 (95% CI, 53-193) and 0.3 (95% CI, 0.14-0.62), respectively. The RNT view is a useful technique for assessing the NB during the first trimester of pregnancy. With this new approach, performance of absent/hypoplastic NB as a marker of aneuploidy, mainly trisomy 21, appears to be similar to that previously reported by using the mid-sagittal plane.

Study on application use of multiplex ligation-dependent probe amplification in rapid prenatal diagnosis of trisomy 21

Objective To evaluate the effectiveness of existing multiplex ligation-dependent probe amplification (MLPA) as a method of rapid prenatal diagnosis for trisomy 21.Methods 181 cases of amniotic fluid samples were detected for chromosome aneuploidies by MLPA.The experimental results were compared with those of G-banding karyotype analysis.Results 181 cases of samples were detected by MLPA,among which 177 cases of normal samples and 4 cases of chromosome aneuploidies were found,including 3 cases of trisomy 21,1 case of X-monomer.This result was consistent with the result of G-banding karyotype analysis.Detection results of MLPA achieved 99.4％ in 24 hours.Conclusion As a rapid prenatal diagnosis technology for trisomy 21,MLPA has good specificity and application value. Key words: Multiplex ligation-dependent probe amplification (MLPA); Rapid prenatal diagnosis; Trisomy 21

The prevalence of non-detectable chromosomal abnormalities by QF-PCR in amniocentesis for certain referral indications: experience at a mainland Chinese hospital

To study the prevalence of non-detectable chromosomal abnormalities by quantitative fluorescent polymerase chain reaction (QF-PCR) in a Chinese population referred for amniocentesis. The karyotype results were reviewed in 8,466 amniotic fluid cultures performed for positive fetal Down syndrome screening or advanced maternal age between January 2002 and June 2012. The karyotype results were classified as detectable or not detectable by QF-PCR, using the assumption that all tests were conducted by this rapid molecular method. Of the 8,466 karyotypes obtained, 211 abnormal karyotypes were found (2.5%). Out of these, 168 cases of common aneuploidies were identified by QF-PCR, and 43 cases of chromosomal abnormalities were missed. The 43 cases missed by QF-PCR included 31 cases predicted to confer no increased risk and 12 with a potential clinical significance. When QF-PCR shows a normal result, the overall residual risk is 0.1% for any clinically significant chromosomal abnormality. A normal QF-PCR result predicts a very low residual risk for patients who are referred solely for an increased risk of a common trisomy.

Early Prenatal Diagnosis of Orofacial Clefts: Evaluation of the Retronasal Triangle Using a New Three-Dimensional Reslicing Technique

Background: The role of three-dimensional ultrasound in the prenatal diagnosis of orofacial clefts is increasing in recent time. Materials and Methods: We obtained three-dimensional data sets of the fetal face from 100 low-risk and 50 high-risk first-trimester fetuses to evaluate the offline reformatting accuracy of the retronasal triangle (RNT) using a novel reslicing technique. Results: Adequate volume data sets for offline analysis were captured in 98% of cases. The RNT view was reformatted in 96% of cases by offline analysis. The secondary palate could be assessed in 93% by offline analysis and an abnormal RNT in the coronal plane was detected in 2 cases of lethal aneuploidy. The false-positive rate was 1.33% in the two studied groups. Conclusion: Abnormal RNT seems to be a valuable ultrasound marker for the early diagnosis of facial clefting. This novel reslicing technique has proven to be easy, fast and accurate, which suggest that this technology could be included in daily practice and integrated with other applications such as multiplanar mode and volume NT. Prospective studies are needed to confirm these promising results and to demonstrate if these diagnostic armamentarium tools will lead to a diagnostic enhancement of cleft lip and palate in early pregnancy.

Computational Investigation of Cancer-Associated Molecular Mechanism in Aurora A (S155R) Mutation

Centrosomes are the key-regulating element of cell cycle progression. Aberrations in their functional mechanism lead to several cancer-related disorders. Aurora A protein is a centrosome-associated protein that regulates the centriole duplication and its abberations are associated with multiple cases of aneuploidy and cancer-related disorders. S155R mutation in Aurora A is reported to induce cancer like phenotype and disrupt its binding with TPX2 protein. In this study, we have demonstrated the structural consequences of Aurora A S155R mutation and the atomic changes that influenced the loss of TPX2-binding affinity. Docking and molecular dynamics simulation results suggested significant loss in atomic contacts between mutant Aurora A and TPX2 protein. Further, we observed a notable changes in conformation of mutant Aurora A-TPX2 docked complex as compared to the native. Loss of binding affinity rendered the TPX2 domain free which then induced unfolding in its coiled region and enabled the overall expansion of mutant complex as compared to the native. The significant outcomes obtained from this study will facilitate in future cancer researches and in developing the potent drug therapies.

Isolated Short Femur Length on Second-Trimester Sonography

To estimate the association between isolated second-trimester short femur length and fetal growth restriction as well as other adverse perinatal outcomes. We conducted a retrospective cohort study of patients with singleton gestations presenting for sonography between 16 and 24 weeks' gestation from 1990 to 2009. Cases of aneuploidy, skeletal dysplasia, and major anomalies were excluded. Short femur length was defined as length below the 10th percentile for gestational age and was considered isolated when both the estimated fetal weight and abdominal circumference were above the 10th percentile for gestational age. Isolated short femur length below the 5th percentile was also evaluated. The primary outcome was fetal growth restriction, defined as birth weight below the 10th percentile. Secondary outcomes included preeclampsia and preterm birth before 37 and 34 weeks. Univariable and multivariable logistic regression analyses were used to estimate the risk of these outcomes in fetuses with isolated short femur length. Of 73,884 patients, 569 (0.8%) had a fetus with a femur length below the 10th percentile, of which 268 (47.1%) were isolated; 210 patients (0.3%) had a fetus with a femur length below the 5th percentile, of which 34 (16.2%) were isolated. Isolated short femur lengths below the 10th and 5th percentiles were associated with an increased risk of fetal growth restriction (<10th: adjusted odds ratio [aOR], 3.4; 95% confidence interval [CI], 2.4-4.6; <5th: aOR, 4.6; 95% CI, 2.0-10.7) and also with an increased risk of preterm birth before 37 and 34 weeks. There was no significant association between isolated short femur length and preeclampsia. Isolated short femur length on second-trimester sonography is associated with a greater than 3-fold increased risk of fetal growth restriction and an increased risk of preterm birth. Serial growth assessment may be warranted in these cases.

Are fetuses with isolated echogenic bowel at higher risk for an adverse pregnancy outcome? Experiences from a tertiary referral center

The purpose of this study was to determine the risk of poor perinatal outcome in normal karyotype second-trimester fetuses with the sonographic finding of isolated echogenic bowel. Medical records, ultrasonographic findings and outcome details were reviewed for 97 cases of isolated fetal echogenic bowel, after excluding cases of aneuploidy and major congenital anomalies, and compared with a cohort of 400 fetuses without pathologic intra-abdominal findings. The incidence of echogenic bowel during the 14-year study period was 0.8%. Eighty (82.5%) pregnancies resulted in healthy, live-born infants. Congenital infection and cystic fibrosis was reported in 6.2% and 4.4%, respectively. The incidence of intrauterine growth restriction and intrauterine fetal demise was significantly higher in the group of isolated echogenic bowels compared with the control group (9.9% versus 1.3%, p ≤ 0.001; 8.9% versus 0.5% p ≤ 0.001). Echogenic bowel is a risk factor for an adverse pregnancy outcome, even in normal karyotype fetuses without congenital anomalies. This information should be considered when counseling patients after midtrimester echogenic bowel is diagnosed.

OP02.06: Aneuploidy: a retrospective review over a 5 year period (from 2007–2011 inclusive) of all known cases of aneuploidy at a large university hospital trust in outer London (Barking, Havering and Redbridge University Hospital)

OP02.06: Aneuploidy: a retrospective review over a 5 year period (from 2007–2011 inclusive) of all known cases of aneuploidy at a large university hospital trust in outer London (Barking, Havering and Redbridge University Hospital)

Array-based comparative genomic hybridization is more informative than conventional karyotyping and fluorescence in situ hybridization in the analysis of first-trimester spontaneous abortion

BackgroundArray-based comparative genomic hybridization (aCGH) is a new technique for detecting submicroscopic deletions and duplications, and can overcome many of the limitations associated with classic cytogenetic analysis. However, its clinical use in spontaneous abortion needs comprehensive evaluation. We used aCGH to investigate chromosomal imbalances in 100 spontaneous abortions and compared the results with G-banding karyotyping and fluorescence in situ hybridization (FISH). Inconsistent results were verified by quantitative fluorescence PCR.ResultsAbnormalities were detected in 61 cases. aCGH achieved the highest detection rate (93.4%, 57/61) compared with traditional karyotyping (77%, 47/61) and FISH analysis (68.9%, 42/61). aCGH identified all chromosome abnormalities reported by traditional karyotyping and interphase FISH analysis, with the exception of four triploids. It also detected three additional aneuploidy cases in 37 specimens with ‘normal’ karyotypes, one mosaicism and 10 abnormalities in 14 specimens that failed to grow in vitro.ConclusionsaCGH analysis circumvents many limitations in traditional karyotyping or FISH. The accuracy and efficiency of aCGH in spontaneous abortions highlights its clinical usefulness for the future. As aborted tissues have the potential to be contaminated with maternal cells, the threshold value of detection in aCGH should be lowered to avoid false negatives.

Application of fluorescence in situ hybridization on detection of abnormal karyotypes from spontaneous abortion specimens

Objective To investigate the effect of fluorescence in situ hybridization (FISH) in increasing the accuracy and detection rate of chromosome aneuploid from spontaneous abortion specimens.Methods Chromosome 13,21,16 and 22 single sequence probes and centromere probes of 18,X and Y chromosome probes were used to detect 100 cases of spontaneous abortion villi samples.The results were compared with conventional karyotype analysis.Results (1) Karyotype analysis:Among 89 successfully cultured villi samples,51 abnormal karyotypes (57.3％) were found,including 37 cases of autosomal aneuploidies,four sex chromosome aneuploidies,two triploids,one tetraploid,one 68,XX and six chromosome structural aberrations.(2) FISH:The detection rate of abnormal karyotype was 38.0％ (38/100),among which 25 cases were autosomal aneuploidies,five sex chromosome aneuploidies,three triploids,four XX chimeras and one triploid in chromosome 13,16,18 and 21.(3) Comparison of the two methods:Among the 11 samples which failed by conventional method,FISH found two abnormal samples.In specimens of 46,XY,three cases showed mosaicism by FISH.In specimens of 46,XX,two cases showed chromosomal abnormalities by FISH.FISH detected overall 65.5％ (38/58) of the chromosomal abnormalities.Conclusions FISH combined with conventional chromosome analysis could improve the accuracy and detection rate of abnormal karyotypes in spontaneous abortion specimens. Key words: Abortion, spontaneous; Chorionic villi; Karyotyping; In situ hybridization,fluorescence

Selenium, Selenoenzymes, Oxidative Stress and Risk of Neoplastic Progression from Barrett's Esophagus: Results from Biomarkers and Genetic Variants

Clinical trials have suggested a protective effect of selenium supplementation on the risk of esophageal cancer, which may be mediated through the antioxidant activity of selenoenzymes. We investigated whether serum selenium concentrations, selenoenzyme activity, oxidative stress and genetic variation in selenoenzymes were associated with the risk of neoplastic progression to esophageal adenocarcinoma (EA) and two intermediate endpoints, aneuploidy and tetraploidy. In this prospective cohort study, during an average follow-up of 7.3 years, 47 EA cases, 41 aneuploidy cases and 51 tetraploidy cases accrued among 361 participants from the Seattle Barrett's Esophagus Research Study who were free of EA at the time of blood draw and had at least one follow-up visit. Development to EA was assessed histologically and aneuploidy and tetraploidy by DNA content flow cytometry. Serum selenium concentrations were measured using atomic absorption spectrometry, activity of glutathione peroxidase (GPX) 1 and GPX3 by substrate-specific coupled test procedures, selenoprotein P (SEPP1) concentrations and protein carbonyl content by ELISA method and malondialdehyde concentrations by HPLC. Genetic variants in GPX1-4 and SEPP1 were genotyped. Serum selenium was not associated with the risk of neoplastic progression to EA, aneuploidy or tetraploidy (P for trend = 0.25 to 0.85). SEPP1 concentrations were positively associated with the risk of EA [hazard ratio (HR) = 3.95, 95% confidence intervals (CI) = 1.42–10.97 comparing the third tertile with the first] and with aneuploidy (HR = 6.53, 95% CI = 1.31–32.58), but not selenoenzyme activity or oxidative stress markers. No genetic variants, overall, were associated with the risk of neoplastic progression to EA (global p = 0.12–0.69). Our results do not support a protective effect of selenium on risk of neoplastic progression to EA. Our study is the first to report positive associations of plasma SEPP1 concentrations with the risk of EA and aneuploidy, which warrants further investigation.

Same‐day prenatal diagnosis of common chromosomal aneuploidies using microfluidics‐fluorescence in situ hybridization

Rapid molecular prenatal diagnostic methods, such as fluorescence in situ hybridization (FISH), quantitative fluorescence-PCR, and multiplex ligation-dependent probe amplification, can detect common fetal aneuploidies within 24 to 48 h. However, specific diagnosis or aneuploidy exclusion should be ideally available within the same day as fetal sampling to alleviate parental anxiety. Microfluidic technologies integrate different steps into a microchip, saving time and costs. We have developed a cost-effective, same-day prenatal diagnostic FISH assay using microfluidics. Amniotic fluids (1-4 mL from 40 pregnant women at 15-22 weeks of gestation) were fixed with Carnoy's before loading into the microchannels of a microfluidic FISH-integrated nanostructured device. The glass slides were coated with nanostructured titanium dioxide to facilitate cell adhesion. Pretreatment and hybridization were performed within the microchannels. Fifty nuclei were counted by two independent analysts, and all results were validated with their respective karyotypes. Of the 40 samples, we found three cases of fetal aneuploidies (trisomies 13, 18, and 21), whereas the remaining 37 cases were normal. Results were concordant with their karyotypes and ready to be released within 3 h of sample receipt. Microfluidic FISH, using 20-fold less than the recommended amount of probe, is a cost-effective method to diagnose common fetal aneuploidies within the same day of fetal sampling.

Stepwise sequential aneuploidy screening in clinical practice

To evaluate stepwise sequential screening (SSS) efficiency in clinical practice. All singletons undergoing SSS in a single practice by NTQR (Nuchal Translucency Quality Review Program)-credentialed providers in a 2-year period were included. Prenatal diagnosis was offered to all screen-positive women and those with a nuchal translucency ≥3.5 mm or cystic hygroma at the 11- to 14-week scan. Data were extracted from prospectively ascertained serum screening and genetics databases. A total of 2,726 patients were screened, with SSS detecting all eight cases of trisomy 21 and all seven cases of other aneuploidies at a 4.3% screen-positive rate. Stepwise sequential screening offers excellent aneuploidy screening efficiency when introduced into clinical practice.

Double Aneuploidy: A Case of Trisomy 21 with XYY

Although aneuploidies are common structural chromosomal abnormalities, double aneuploidies involving chromosomes 21 and Y are very rare. Here we report a case of double aneuploidy involving chromosomes 21 and Y in a 5 day old baby with jaundice and polycythemia. The diagnosis was confirmed by karyotype analysis using modified “whole blood” and microtechnique methods followed by Giemsa-Trypsin-Leishman (GTL) banding technique. The patient had typical features of Down syndrome, however, phenotypic features of XYY was not present. In addition, the patient also had atrial septal defect, multiple trabecular small ventricular septal defect, and moderate degree of pulmonary hypertension. Etiological predisposing factor for 48,XYY,+21 is not known. It is difficult to determine the incidence, phenotypic properties, and recurrence risk of 48,XYY,+21.

Echogenic Bowel on Second-Trimester Ultrasonography

To estimate if echogenic bowel diagnosed on second-trimester ultrasonography has an independent risk association with intrauterine growth restriction (IUGR) and intrauterine fetal demise. This is a retrospective cohort study of all patients with singleton gestations who presented to our institution for second-trimester ultrasonography between 1990 and 2008. Study groups were defined by the presence or absence of echogenic bowel. Primary outcomes were IUGR, defined as birth weight less than the 10th percentile for gestational age and intrauterine fetal demise at 20 weeks or more of gestation. Univariable and multivariable logistic regression analyses were used to estimate the risk of intrauterine fetal demise and IUGR in fetuses with echogenic bowel. Analyses were repeated after excluding cases of aneuploidy, cytomegalovirus (CMV) infection, other major congenital anomalies, and abnormal second-trimester serum screening results. Of 64,048 patients, the incidence of echogenic bowel was 0.4%. Of these, echogenic bowel was an isolated finding in 188 (72.3%) cases. There were 579 (0.9%) cases of intrauterine fetal demise and 8,173 (12.8%) cases of IUGR in the entire cohort. After excluding cases of aneuploidy and CMV infection, the incidence of intrauterine fetal demise was 7.3% in the echogenic bowel group compared with 0.9% in the nonechogenic bowel group, translating to an absolute risk increase of 6.4%. The incidence of IUGR in the echogenic bowel group was 19.5% compared with 12.9% in the nonechogenic bowel group (absolute risk increase, 6.6%). After controlling for potential confounders, echogenic bowel was significantly associated with both intrauterine fetal demise (adjusted odds ratio [OR] 9.6, 95% confidence interval [CI] 5.8-15.9) and IUGR (adjusted OR 2.1, 95% CI 1.5-2.9). This risk association remained significant even when evaluating echogenic bowel as an isolated sonographic finding. The presence of echogenic bowel on ultrasonography is independently associated with an increased risk for both IUGR and intrauterine fetal demise. Serial growth assessment and antenatal testing may be warranted in these patients.

Fetal nuchal translucency thickness in different cut‐off points for aneuploidy screening in the south of Vietnam

The purpose of this study was to define the most suitable cut-off point for fetal nuchal translucency thickness in a screening program for aneuploidy and trisomy 21 in the south of Vietnam. Two thousand and five hundred cases of singleton pregnancies were followed prospectively from the first trimester to the delivery. The rate of aneuploidy was calculated by seeking a relationship to increased fetal nuchal translucency thickness then calculating the sensitivity and specificity of different cut-off points in thickness measurement to find the most suitable point for screening. The prevalence of fetal abnormality was 1.5% (95% CI 1.1-2.1), and 1.2% (95% CI 0.8-1.7) of aneuploidy cases found and the commonest was trisomy 21. A cut-off point at 2.4 mm showed the highest level of sensitivity and specificity for the detection of aneuploidy (65.5 and 95.7%) and trisomy 21 (75.0 and 95.1%), with a false-positive rate of 4.3 and 4.9%, respectively. Using a cut-off point of nuchal translucency at 2.4 mm has potential for aneuploidy and trisomy 21 screening in the south of Vietnam.

Triple-X Syndrome in a Trisomic Down Syndrome Child: Both Aneuploidies Originated from the Mother

Here we report a case of double aneuploidy showing trisomy 21 and triple-X chromosome in a case of Down syndrome born to young non-consanguineous parents. The child presented with strabismus, perio...

Prenatal diagnosis of congenital vascular rings and slings: sonographic features and perinatal outcome in 81 consecutive cases

To describe the sonographic features and perinatal outcome of congenital vascular rings diagnosed prenatally at a single tertiary care institution. All cases of congenital vascular rings diagnosed by prenatal ultrasound between July 2005 and December 2009 were identified at a single referral center using an established perinatal database. The diagnosis was confirmed by postnatal echocardiography for live-born infants or autopsy for terminated cases. The overall incidence of vascular ring during this 5-year period was 0.086% (81 cases among 94 321 women undergoing perinatal ultrasound examination). Forty-four cases had complete O-shaped (n = 3) or U-shaped (n = 41) vascular rings, and 37 cases had incomplete C-shaped vascular rings (vascular slings). The most common type of vascular ring seen in 50.6% (41/81) of cases was a right aortic arch with aberrant left subclavian artery. The second most common type was a left aortic arch with an aberrant right subclavian artery [39.5% (32/81)]. Chromosomal analysis was performed prenatally in 46 pregnancies, and six cases (13.0%) of fetal aneuploidy were identified. Congenital vascular rings can be diagnosed with prenatal ultrasound using the three-vessel trachea view and subsequent fetal echocardiography with particular attention to the relationship of the aortic arches, ductal arches, and the trachea.