Mosaic trisomy 13 is estimated to occur in 5% of all trisomy 13 cases. Presentation of trisomy 13 mosaicism is highly variable, with cases that may present with a normal phenotype and intellectual function, to cases with grossly abnormal features and profound developmental delays. We present a 2-year-old female with trisomy 13 mosaicism, who presented with small for gestational age (SGA), polydactyly, ventricular septal defect (VSD), and poor oral feeding.
Trisomy 13 Syndrome ; Genetic Counseling

OBJECTIVE: To explore whether it is necessary to choose NIPT-plus for the prenatal screening of pregnant women. METHODS: The results of NIPT and NIPT-plus sequencing data, fetal DNA concentration, prenatal diagnosis and pregnancy outcome of 50 pregnant women were compared. RESULTS: Compared with NIPT, NIPT-plus attained similar fetal DNA concentration and a 4.4-fold increase in sequencing data. NIPT was able to detect 4 cases of 21-trisomy, 2 cases of 18-trisomy, and 9 cases of sex chromosome aneuploidies (SCAs) signaled by NIPT-plus, but missed one 18-trisomy, and failed to detect rare chromosome aneuploidies (RCAs) and microdeletion/microduplication syndromes (MMS). The PPVs of NIPT-plus for 21-trisomy, 18-trisomy, SCAs, MMS and RCAs were 100%, 100%, 44.4%, 30.4% and 0%, respectively. And those of NIPT for 21-trisomy, 18-trisomy, and SCAs were 100%, 100%, and 44.4%, respectively. CONCLUSION It is necessary for pregnant women to select NIPT-plus to improve the detection rate of common trisomies, SCAs and disease-specific MMS, therefore reduce the occurrene of birth defect.
Aneuploidy ; Female ; Humans ; Pregnancy ; Pregnant Women ; Prenatal Diagnosis ; Trisomy ; Trisomy 13 Syndrome ; Trisomy 18 Syndrome

Chromosome Disorders ; Chromosomes, Human, Pair 13 ; Humans ; Infant ; Male ; Trisomy ; Trisomy 13 Syndrome

OBJECTIVE: To evaluate the efficacy of non-invasive prenatal testing (NIPT) in the prenatal screening and its role in the system of prenatal diagnosis. METHODS: A total of 22 649 singleton pregnant women who were registered and finally delivered or had induced labor at Beijing Obstetrics and Gynecology Hospital of Capital Medical University were enrolled. The routes of prenatal screening were analyzed to evaluate the efficacy of prenatal screening. Meanwhile, 9268 pregnant women who underwent invasive prenatal diagnosis procedure were enrolled. The indications and results of prenatal diagnosis were analyzed to evaluate the effectiveness of prenatal screening. RESULTS: 60.24% of singleton pregnant women have opted for Down syndrome screening, and their age was mainly under 35. The proportion of women opted for NIPT was 34.74%, and were mainly between 35 and 39. The overall diagnostic rate of trisomy 21, 18 and 13 trisomy for those with high risk by NIPT was 0.89%, which yielded a positive predictive value of 75.71%. For those with moderate risk by serum screening, 0.30% was predicted with a high risk by NIPT. Among women undergoing prenatal diagnosis, 63.04% and 21.22% had the indication of advanced age or high risk by serum screening, and the positive predictive values were 5.1% and 5.13%, respectively. By contrast, 2.30% of women undergoing prenatal diagnosis had a high risk by NIPT, which yielded a positive predictive value of 54.46%. CONCLUSION With the change of the age composition of pregnant women and increase in the complexity of pregnancy in China, to build a prenatal screening system based on NIPT will be helpful to improve the efficiency of the current system of prenatal screening and diagnosis.
China ; Down Syndrome/genetics* ; Female ; Humans ; Pregnancy ; Prenatal Diagnosis ; Trisomy 13 Syndrome ; Trisomy 18 Syndrome

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.
Female ; Humans ; Karyotyping ; Microarray Analysis ; Pregnancy ; Prenatal Diagnosis ; Trisomy 13 Syndrome/genetics* ; Trisomy 18 Syndrome

OBJECTIVE: To assess the value of non-invasive prenatal testing (NIPT) for the detection of fetal chromosomal aneuploidies in women with twin pregnancy. METHODS: A total of 2473 women with twin pregnancy underwent the NIPT test to assess the risk for fetal chromosomal aneuploidies from January 2016 to September 2019. Those with a high risk by NIPT were confirmed by amniocentesis or chorionic villus sampling. All cases were followed up to evaluate the positive prediction value of NIPT for twin pregnancies. RESULTS: Among the 2473 women, the NIPT test has identified 31 cases (1.25%) with a high risk for fetal chromosomal aneuploidies, which included 5 cases of trisomy 21, 1 case of chromosome 21 deletion, 4 cases of trisomy 18, 7 cases of sex chromosome abnormality and 14 cases of microdeletion and microduplication. By invasive prenatal diagnosis or chromosomal karyotyping analysis of neonates, 5 cases of trisomy 21, 3 cases of trisomy 18, 1 case of sex chromosome abnormality, and 2 cases of microdeletion and microduplication were confirmed, which yielded a positive predictive value of 100%, 75%, 25% and 25%, respectively. CONCLUSION NIPT can be used for the screening of fetal chromosomal aneuploidies in women with twin pregnancy with high accuracy. The method is non-invasive, safe and effective for the screening of fetal chromosomal aneuploidies, in particular trisomy 21.
Aneuploidy ; Chromosome Disorders ; Female ; Humans ; Infant, Newborn ; Pregnancy ; Pregnancy, Twin ; Prenatal Diagnosis ; Trisomy ; Trisomy 13 Syndrome ; Trisomy 18 Syndrome

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 313, the PPV for trisomy 21 was 80% (8/10) for those>35 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 313. NIPT showed that the positive predictive value of trisomy 13 was only 6.67% (1/15) when the trisomy 13 Z value was more than 20, the positive predictive value was 100% , and the trisomy 13 Z value was 3CONCLUSION NIPT is a technique similar to prenatal diagnosis and has a high positive predictive value for trisomies 18 and 21. Proper classification and division of the high-risk Z value of NIPT can further improve the positive predictive values for trisomies 21, 18 and 13 in different intervals, and is more helpful to guide clinicians in genetic counseling for high-risk pregnant women. Meanwhile, the compliance of prenatal diagnosis in high risk NIPT pregnant women with Z value between 3~13 was improved.
Female ; Pregnancy ; Humans ; Trisomy 13 Syndrome/genetics* ; Trisomy/genetics* ; Down Syndrome/genetics* ; Chromosome Disorders/genetics* ; Trisomy 18 Syndrome/diagnosis* ; Prenatal Diagnosis/methods*

As a prenatal testing for chromosomal abnormalities, non-invasive prenatal testing (NIPT) has been integrated into prenatal healthcare service. NIPT has shown a high sensitivity and specificity for screening fetal trisomies 13, 18 and 21, and has attained excellent clinical results. With the propagation of the NIPT screening, international organizations have issued guidelines and comments for its clinical utility with regular updating. China has also developed guidelines for NIPT in 2016. NIPT guidelines in various countries have provided valuable guidance for its target diseases and suitable patient groups, but there has been few research data on its clinical application for special groups of patients. Based on the guidelines and comments of various professional bodies and published data on the clinical utility of NIPT, in addition with consideration of the conditions in China, clinical utility of NIPT for particular groups of pregnant women, including those with advanced maternal age, obesity, twin pregnancy and fetal ultrasonographic anomalies, are reviewed. The value of genetic counseling for NIPT is also emphasized, which is critical for the clinical application of NIPT.
China ; Chromosome Aberrations ; Female ; Humans ; Pregnancy ; Pregnant Women ; Prenatal Diagnosis ; Trisomy 13 Syndrome

OBJECTIVETo assess the value of combined fetal karyotyping and chromosomal microarray analysis (CMA) for the verification of high-risk pregnancy signaled by noninvasive prenatal screening (NIPS) based on high-throughput sequencing.

METHODSOne hundred and fifty-one pregnant women with high risks for aneuploidies of chromosomes 13, 18, 21, X and Y or pathological copy number variations (CNVs) by NIPS were subjected to amniocytic karyotyping and CMA analysis.

RESULTSOne hundred and forty-two women were found to have a high risk for fetal chromosomal aneuploidies, which included 83 cases of trisomy 21, 17 cases of trisomy 18, 2 cases of trisomy 13, and 40 cases of sex chromosome aneuploidies. Amniocytic karyotyping and CMA analysis has confirmed 81 cases of trisomy 21, 15 cases of trisomy 18, 10 cases of 47,XXY, 4 cases of 47,XXX, 2 cases of 47,XYY and 1 case of 46,X,del(X)(q26.1). Two trisomy 21, two trisomy 18, 2 trisomy 13, and 23 cases of sex chromosomal aneuploidies were verified as false positives. For 9 women with pathological fetal CNVs detected by NIPS, combined fetal karyotyping and CMA has confirmed 1 case of chromosome 13 microdeletion, 1 case of chromosome 18 microduplication, and 1 case of chromosome 18 deletion. For a case with 30 Mb duplication of chromosome 2 and 25 Mb duplication of chromosome 8, CMA analysis had no positive finding, while fetal umbilical cord blood karyotyping has yielded a 46,XX,dup(2)(p23.1p25.3)[13]/46,XX[87] karyotype. The remaining 5 cases were confirmed as false positive results.

CONCLUSIONCombined fetal karyotyping and CMA has provided a powerful tool for verifying high-risk fetuses signaled by NIPS.

Aneuploidy ; DNA Copy Number Variations ; Down Syndrome ; Female ; High-Throughput Nucleotide Sequencing ; methods ; Humans ; Karyotyping ; Microarray Analysis ; Pregnancy ; Prenatal Diagnosis ; Trisomy 13 Syndrome ; Trisomy 18 Syndrome

OBJECTIVE: To assess the value of non-invasive prenatal testing (NIPT) for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies, chromosomal microdeletions and microduplications using cell-free fetal DNA from peripheral blood samples of pregnant women. METHODS: A total of 15 237 pregnant women who had undergone NIPT testing at the Maternity and Child Health Care Hospital of Zaozhuang from February 2015 to December 2021 were enrolled in this study. For those with a high risk by NIPT, amniotic fluid samples were collected for G-banding chromosomal karyotyping analysis and chromosomal microarray analysis to verify the consistency of NIPT with results of prenatal diagnosis. All of the women were followed up by telephone for pregnancy outcomes. RESULTS: Among the 15 237 pregnant women, 266 (1.75%) were detected with a high risk for fetal chromosomal abnormality were detected. Among these, 79 (29.7%) were at a high risk for T21, 26 (9.77%) were at a high risk for T18, 9 (3.38%) were at a high risk for T13, 74 (27.82%) were at a high risk for sex chromosome aneuploidies, 12 (4.51%) were at a high risk for other autosomal aneuploidies, and 66 (24.81%) were at a high risk for chromosomal microdeletions or microduplications. 217 women had accepted invasive prenatal diagnosis and respectively 50, 13, 1, 25, 1 and 18 were confirmed with T21, T18, T13, sex chromosome aneuploidies, autosomal aneuploidies and microdeletions/microduplications, and the positive predictive values were 75.76%, 68.42%, 11.11%, 40.32%, 10% and 35.29%, respectively. For 13 042 women (85.59%), the outcome of pregnancy were successfully followed up. During the follow-up, one false negative case of T21 was discovered. No false positive cases for T13 and T18 were found. CONCLUSION NIPT has a sound performance for screening T13, T18 and T21, and is also valuable for screening other autosomal aneuploidies, sex chromosome aneuploidies and chromosomal microdeletions/microduplications.
Child ; Female ; Pregnancy ; Humans ; Retrospective Studies ; Cell-Free Nucleic Acids ; Chromosome Disorders/genetics* ; Prenatal Diagnosis/methods* ; Down Syndrome/genetics* ; Sex Chromosome Aberrations ; Trisomy 18 Syndrome/genetics* ; Trisomy 13 Syndrome/diagnosis* ; Aneuploidy ; DNA/genetics* ; Trisomy/genetics*