scholarly journals Initial Clinical Experience with NIPT for Rare Autosomal Aneuploidies and Large Copy Number Variations

2022 ◽  
Vol 11 (2) ◽  
pp. 372
Author(s):  
Thomas Harasim ◽  
Teresa Neuhann ◽  
Anne Behnecke ◽  
Miriam Stampfer ◽  
Elke Holinski-Feder ◽  
...  

Objective: Amniocentesis, chorionic villi sampling and first trimester combined testing are able to screen for common trisomies 13, 18, and 21 and other atypical chromosomal anomalies (ACA). The most frequent atypical aberrations reported are rare autosomal aneuploidies (RAA) and copy number variations (CNV), which are deletions or duplications of various sizes. We evaluated the clinical outcome of non-invasive prenatal testing (NIPT) results positive for RAA and large CNVs to determine the clinical significance of these abnormal results. Methods: Genome-wide NIPT was performed on 3664 eligible patient samples at a single genetics center. For patients with positive NIPT reports, the prescribing physician was asked retrospectively to provide clinical follow-up information using a standardized questionnaire. Results: RAAs and CNVs (>7 Mb) were detected in 0.5%, and 0.2% of tested cases, respectively. Follow up on pregnancies with an NIPT-positive result for RAA revealed signs of placental insufficiency or intra-uterine death in 50% of the cases and normal outcome at the time of birth in the other 50% of cases. We showed that CNV testing by NIPT allows for the detection of unbalanced translocations and relevant maternal health conditions. Conclusion: NIPT for aneuploidies of all autosomes and large CNVs of at least 7 Mb has a low “non-reportable”-rate (<0.2%) and allows the detection of additional conditions of clinical significance.

2020 ◽  
Author(s):  
Xiaodong Gu ◽  
Sudong Liu ◽  
Huaxian Wang ◽  
Ruiqiang Weng ◽  
Xuemin Guo ◽  
...  

Abstract Background To investigate the frequency of fetal chromosomal abnormalities among women with abnormal ultrasound, abnormal biochemical marker screening or noninvasive prenatal testing results, advanced maternal age, or history of miscarriage in southern China. Methods We retrospectively analyzed prenatal samples from pregnant women between 2015 and 2019. Conventional karyotyping was performed using GTG banding. Copy number variation sequencing was used when indicated to identify chromosomal abnormalities. Results A total of 2,318 prenatal samples (188 chorionic villus samples, 2,003 amniotic fluids, and 127 cord blood) were analyzed. The frequency of chromosomal abnormalities was 12.4% (288/2,318) in prenatal samples, and frequency in chorionic villus samples (23.9%) was higher than in amniotic fluids (13.5%) and in cord blood (5.0%; P < 0.001). Numerical anomalies were detected in 195 (8.4%) cases and the most common abnormality were trisomy 21 (103/2,318; 4.4%), trisomy 18 (31/2,318; 1.3%) and monosomy X (18/2,318; 0.8%). Sructural anomalies were found in 29 (1.3%) cases, rare anomalies such as deletions (4 cases), duplications (2 cases), and complex rearrangement (1 case), were detected. Two cases with common chromosomal polymorphisms, inv(9)(p11q12) and inv(9)(p11q13), associated with recurrent spontaneous abortion, were detected. Five fetuses had normal karyotypes and definite pathogenic copy number variations, with microdeletions at 16p13.11, 16p12.1 (2 cases), and 17p12 and a microduplication at 7q11.23; all had normal phenotypes after birth. Conclusion Our study indicated that fetal chromosomal anomalies can be detected in early gestation and provided valuable information for interpretation of chromosomal polymorphisms and copy number variations.


2020 ◽  
Author(s):  
Yuefang Liu ◽  
Longfei Cheng ◽  
Yuan Peng ◽  
Zhe Liang ◽  
Pan Qiong

Abstract Background: With the development of whole-genome sequencing, small sub-chromosomal deletions and duplications could be found by non-invasive prenatal testing(NIPT). This study aimed to review the efficiency of NIPT as a screening test for aneuploidies and sub-chromosomal copy number variations (CNVs) in 24359 single pregnancies.Methods: A total of 24359 single pregnancies with different clinical indications were retrospectively analyzed. The positive predictive value (PPV)of chromosome aneuploidies and subchromosomal CNVs were analyzed. Pathogenicity of abnormal NIPT results were assessed according to American College of Medical Genetics and Genomics(ACMG). Results: A total of 442 pregnancies (442/24359,1.9%) were with abnormal NIPT results. PPV for trisomy 21(T21), trisomy 18 (T18), trisomy 13 (T13), and sex chromosome aneuploidies (SCAs) was 84.8%, 54.2%, 11.1% an 40.5% respectively. The PPV for sub-chromosomal CNVs was 59.0% (46/78). The PPV for CNVs ≤5 Mb was 68.9% (31/45), for CNVs within 5-10 Mb was 83.3%(5/6) and for CNVs ≥10 Mb was 37.1% (10/27) respectively. The clinical information, prenatal diagnosis results and follow-up results of 46 true positive cases, 6 cases with sub-chromosomal CNVs inconsistent with NIPT and 1 false negative case were also described in detail.Conclusions: Our data have potential significance in demonstrating the significance of NIPT not only for common whole chromosome aneuploidies but also for sub-chromosomal CNVs. Besides, the clinical information, prenatal diagnosis results and follow-up results of 52 cases with sub-chromosomal CNVs and 1 false negative case would provide important guidance for genetic counseling.


2020 ◽  
Author(s):  
yuefang Liu ◽  
Longfei Cheng ◽  
Yuan Peng ◽  
Zhe Liang ◽  
Xin Jin ◽  
...  

Abstract Background: With the development of whole-genome sequencing, small subchromosomal deletions and duplications could be found by non-invasive prenatal testing(NIPT). Our study is aimed to review the efficacy of NIPT as a screening test for aneuploidies and subchromosomal copy number variations (CNVs) in 24359 single pregnancies.Methods: A total of 24359 single pregnancies with different clinical features were retrospectively analyzed. Pathogenicity of abnormal NIPT results were assessed according to American College of Medical Genetics and Genomics(ACMG). Chromosome aneuploidies and subchromosomal CNVs were confirmed by karyotyping and chromosomal microarray analysis(CMA). Results: A total of 442 pregnancies (442/24359,1.9%) were with abnormal NIPT results. The positive predictive value (PPV) for trisomy 21(T21), trisomy 18 (T18), trisomy 13 (T13), and sex chromosome aneuploidies (SCAs) was 84.8%, 54.2%, 11.1% an 40.5% respectively. The PPV for subchromosomal CNVs was 59.0% (46/78). The clinical information, prenatal diagnosis results and follow-up results of 46 true positive cases, 6 cases with subchromosomal CNVs inconsistent with NIPT and 1 case of false negative were also demonstrated in detail.Conclusion: Our data have potential significance in demonstrating the significance of NIPT not only for common whole chromosome aneuploidies but also for subchromosomal CNV. Besides, the clinical information, prenatal diagnosis results and follow-up results of 52 cases with subchromosomal CNV and 1 case of false negative would provide important guidance for genetic counseling.


2021 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Nayoung Han ◽  
Jung Mi Oh ◽  
In-Wha Kim

For predicting phenotypes and executing precision medicine, combination analysis of single nucleotide variants (SNVs) genotyping with copy number variations (CNVs) is required. The aim of this study was to discover SNVs or common copy CNVs and examine the combined frequencies of SNVs and CNVs in pharmacogenes using the Korean genome and epidemiology study (KoGES), a consortium project. The genotypes (N = 72,299) and CNV data (N = 1000) were provided by the Korean National Institute of Health, Korea Centers for Disease Control and Prevention. The allele frequencies of SNVs, CNVs, and combined SNVs with CNVs were calculated and haplotype analysis was performed. CYP2D6 rs1065852 (c.100C>T, p.P34S) was the most common variant allele (48.23%). A total of 8454 haplotype blocks in 18 pharmacogenes were estimated. DMD ranked the highest in frequency for gene gain (64.52%), while TPMT ranked the highest in frequency for gene loss (51.80%). Copy number gain of CYP4F2 was observed in 22 subjects; 13 of those subjects were carriers with CYP4F2*3 gain. In the case of TPMT, approximately one-half of the participants (N = 308) had loss of the TPMT*1*1 diplotype. The frequencies of SNVs and CNVs in pharmacogenes were determined using the Korean cohort-based genome-wide association study.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yunsheng Ge ◽  
Jia Li ◽  
Jianlong Zhuang ◽  
Jian Zhang ◽  
Yanru Huang ◽  
...  

Abstract Background Noninvasive prenatal testing (NIPT) has been wildly used to screen for common aneuplodies. In recent years, the test has been expanded to detect rare autosomal aneuploidies (RATs) and copy number variations (CNVs). This study was performed to investigate the performance of expanded noninvasive prenatal testing (expanded NIPT) in screening for common trisomies, sex chromosomal aneuploidies (SCAs), rare autosomal aneuploidies (RATs), and copy number variations (CNVs) and parental willingness for invasive prenatal diagnosis in a Chinese prenatal diagnosis center. Methods A total of 24,702 pregnant women were retrospectively analyzed at the Women and Children’s Hospital from January 2013 to April 2019, among which expanded NIPT had been successfully conducted in 24,702 pregnant women. The high-risk expanded NIPT results were validated by karyotype analysis and chromosomal microarray analysis. All the tested pregnant women were followed up for pregnancy outcomes. Results Of the 24,702 cases, successful follow-up was conducted in 98.77% (401/446) of cases with common trisomies and SCAs, 91.95% (80/87) of RAT and CNV cases, and 76.25% (18,429/24,169) of cases with low-risk screening results. The sensitivity of expanded NIPT was 100% (95% confidence interval[CI], 97.38–100%), 96.67%(95%CI, 82.78–99.92%), and 100%(95%CI, 66.37–100.00%), and the specificity was 99.92%(95%CI, 99.87–99.96%), 99.96%(95%CI, 99.91–99.98%), and 99.88% (95%CI, 99.82–99.93%) for the detection of trisomies 21, 18, and 13, respectively. Expanded NIPT detected 45,X, 47,XXX, 47,XXY, XYY syndrome, RATs, and CNVs with positive predictive values of 25.49%, 75%, 94.12%, 76.19%, 6.45%, and 50%, respectively. The women carrying fetuses with Trisomy 21/Trisomy 18/Trisomy 13 underwent invasive prenatal diagnosis and terminated their pregnancies at higher rates than those at high risk for SCAs, RATs, and CNVs. Conclusions Our study demonstrates that the expanded NIPT detects fetal trisomies 21, 18, and 13 with high sensitivity and specificity. The accuracy of detecting SCAs, RATs, and CNVs is still relatively poor and needs to be improved. With a high-risk expanded NIPT result, the women at high risk for common trisomies are more likely to undergo invasive prenatal diagnosis procedures and terminate their pregnancies than those with unusual chromosome abnormalities.


2021 ◽  
Author(s):  
Chiel F. Ebbelaar ◽  
Anne M. L. Jansen ◽  
Lourens T. Bloem ◽  
Willeke A. M. Blokx

AbstractCutaneous intermediate melanocytic neoplasms with ambiguous histopathological features are diagnostically challenging. Ancillary cytogenetic techniques to detect genome-wide copy number variations (CNVs) might provide a valuable tool to allow accurate classification as benign (nevus) or malignant (melanoma). However, the CNV cut-off value to distinguish intermediate lesions from melanoma is not well defined. We performed a systematic review and individual patient data meta-analysis to evaluate the use of CNVs to classify intermediate melanocytic lesions. A total of 31 studies and 431 individual lesions were included. The CNV number in intermediate lesions (median 1, interquartile range [IQR] 0–2) was significantly higher (p<0.001) compared to that in benign lesions (median 0, IQR 0–1) and lower (p<0.001) compared to that in malignant lesions (median 6, IQR 4–11). The CNV number displayed excellent ability to differentiate between intermediate and malignant lesions (0.90, 95% CI 0.86–0.94, p<0.001). Two CNV cut-off points demonstrated a sensitivity and specificity higher than 80%. A cut-off of ≥3 CNVs corresponded to 85% sensitivity and 84% specificity, and a cut-off of ≥4 CNVs corresponded to 81% sensitivity and 91% specificity, respectively. This individual patient data meta-analysis provides a comprehensive overview of CNVs in cutaneous intermediate melanocytic lesions, based on the largest pooled cohort of ambiguous melanocytic neoplasms to date. Our meta-analysis suggests that a cut-off of ≥3 CNVs might represent the optimal trade-off between sensitivity and specificity in clinical practice to differentiate intermediate lesions from melanoma.


Placenta ◽  
2011 ◽  
Vol 32 ◽  
pp. S282
Author(s):  
Paola Scaruffi ◽  
Sara Stigliani ◽  
Annamaria Jane Nicoletti ◽  
Pier Luigi Venturini ◽  
Gian Paolo Tonini ◽  
...  

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Pablo Oliveira ◽  
Gustavo N. O. Costa ◽  
Andresa K. A. Damasceno ◽  
Fernando P. Hartwig ◽  
George C. G. Barbosa ◽  
...  

BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 517 ◽  
Author(s):  
Hui Zhang ◽  
Zhi-Qiang Du ◽  
Jia-Qiang Dong ◽  
Hai-Xia Wang ◽  
Hong-Yan Shi ◽  
...  

2020 ◽  
Author(s):  
Marcel Kucharik ◽  
Jaroslav Budis ◽  
Michaela Hyblova ◽  
Gabriel Minarik ◽  
Tomas Szemes

Copy number variations (CNVs) are a type of structural variant involving alterations in the number of copies of specific regions of DNA, which can either be deleted or duplicated. CNVs contribute substantially to normal population variability; however, abnormal CNVs cause numerous genetic disorders. Nowadays, several methods for CNV detection are used, from the conventional cytogenetic analysis through microarray-based methods (aCGH) to next-generation sequencing (NGS). We present GenomeScreen - NGS based CNV detection method based on a previously described CNV detection algorithm used for non-invasive prenatal testing (NIPT). We determined theoretical limits of its accuracy and confirmed it with extensive in-silico study and already genotyped samples. Theoretically, at least 6M uniquely mapped reads are required to detect CNV with a length of 100 kilobases (kb) or more with high confidence (Z-score > 7). In practice, the in-silico analysis showed the requirement at least 8M to obtain >99% accuracy (for 100 kb deviations). We compared GenomeScreen with one of the currently used aCGH methods in diagnostic laboratories, which has a 200 kb mean resolution. GenomeScreen and aCGH both detected 59 deviations, GenomeScreen furthermore detected 134 other (usually) smaller variations. Furthermore, the overall cost per sample is about 2-3x lower in the case of GenomeScreen.


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