After the promulgation of the first edition of expert consensus on the application of chromosomal microarray analysis (CMA) technology in prenatal diagnosis in 2014, after 8 years of clinical and technical development, CMA technology has become a first-line diagnosis technology for fetal chromosome copy number deletion or duplication abnormalities, and is widely used in the field of prenatal diagnosis in China. However, with the development of the industry and the accumulation of experience in case diagnosis, the application of CMA technology in many important aspects of prenatal diagnosis, such as clinical diagnosis testimony, data analysis and genetic counseling before and after testing, needs to be further standardized and improved, so as to make the application of CMA technology more in line with clinical needs. The revision of the guideline was led by the National Prenatal Diagnostic Technical Expert Group, and several prenatal diagnostic institutions such as Peking Union Medical College Hospital were commissioned to write, discuss and revise the first draft, which was discussed and reviewed by all the experts of the National Prenatal Diagnostic Technical Expert Group, and was finally formed after extensive review and revision. This guideline is aimed at the important aspects of the application of CMA technology in prenatal diagnosis and clinical diagnosis, from the clinical application of evidence, test quality control, data analysis and interpretation, diagnosis report writing, genetic counseling before and after testing and other work specifications are elaborated and introduced in detail. It fully reflects the integrated experience, professional thinking and guidance of the current Chinese expert team on the prenatal diagnosis application of CMA technology. The compilation of the guideline for the application of CMA technology in prenatal diagnosis will strive to promote the standardization and advancement of prenatal diagnosis of fetal chromosome diseases in China.
Female ; Humans ; Pregnancy ; Asian People ; Chromosome Aberrations ; Chromosome Deletion ; Chromosome Duplication/genetics* ; DNA Copy Number Variations/genetics* ; Fetal Diseases/genetics* ; Genetic Counseling ; Microarray Analysis ; Prenatal Care ; Prenatal Diagnosis ; Practice Guidelines as Topic

Objective To explore the clinical significance of non-invasive prenatal testing(NIPT)for fetal chromosomal abnormalities in the cases of twin pregnancy and its relationship with age and other related factors.Methods A total of 3733 women with twin pregnancy of 12-26⁺⁶ weeks who voluntarily underwent NIPT in the Ningbo Women and Children's Hospital from January 2018 to December 2022 were selected.The results of NIPT and amniocentesis were compared and all the participants were followed up.The detection rate of chromosomal abnormalities by NIPT was calculated,and its correlations with age,gestational weeks,chorionicity,and pregnancy type were analyzed.Results Among the 3733 cases,71 cases of fetal chromosome abnormality were indicated by NIPT,including 13 cases of trisomy 21,19 cases of trisomy 18,5 cases of trisomy 13,18 cases of sex chromosome abnormality,and 16 cases of chromosome microdeletion/duplication(excluding 21,18,13,and sex chromosomes),among which 34 cases were true positive and 37 cases were false positive.The overall sensitivity,specificity,and positive predictive value(PPV)of NIPT for chromosomal abnormalities in the cases of twin pregnancy were 100%,98.99%,and 47.89%(34/71),respectively.NIPT showed the sensitivity,specificity,and PPV of 100%,99.78%,and 78.38%(29/37)for trisomy 21,18,and 13,100%,99.56%,and 16.67%(3/18)for sex chromosome abnormalities,and 100%,99.62%,and 12.5%(2/16)for chromosome microdeletion/duplication,respectively.In the age group of ≥40 years,the NIPT for chromosomal abnormalities showed the PPV of 66.67%,the sensitivity of 100%,and the misdiagnosis rate of 30%。However,the NIPT for trisomy 21,18,and 13 showed the PPV of 100%,the misdiagnosis rate of 0,and the sensitivity and specificity of 100%.In terms of grouping based on gestational weeks,the NIPT for chromosomal abnormalities showed the highest PPV(51.28%)in the women with twin pregnancy for 14-17⁺⁶ weeks,followed by that(50.00%)in the women with twin pregnancy for 22-26⁺⁶ weeks;the NIPT for trisomy 21,18,and 13 showed the highest PPV of 94.74% in the gestation group of 14-17⁺⁶ weeks,followed by that(83.33%)in the gestation group of 18-21⁺⁶ weeks.The rate of dichorionic diamniotic twins was higher in assisted pregnancies than in natural pregnancies,and NIPT showed the same detection efficiency for dichorionic diamniotic twins and monochorionic diamniotic twins and the same detection efficiency for different pregnancy types.Conclusions NIPT has high accuracy in the diagnosis of twin pregnancy and high sensitivity and high specificity for different ages and gestational weeks,especially for trisomy 21,18,and 13.NIPT is suitable for assisted pregnancy and natural pregnancy,and it is of high value in clinical application.However,extensive application needs a large population-based study.
Pregnancy ; Child ; Female ; Humans ; Adult ; Down Syndrome/genetics* ; Pregnancy, Twin ; Prenatal Diagnosis ; Trisomy ; Chromosome Aberrations

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_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_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.
Humans ; Female ; Pregnancy ; Trisomy 13 Syndrome/genetics* ; DNA Copy Number Variations ; Placenta ; Chromosomes, Human, Pair 1 ; In Situ Hybridization, Fluorescence ; Prenatal Diagnosis/methods* ; Fetus ; Amniotic Fluid ; Chromosome Aberrations ; Trisomy/genetics*

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*

OBJECTIVE: To carry out genetic analysis for a Chinese pedigree affected with intellectual disability and overgrowth due to a supernumerary marker chromosome (sSMC). METHODS: A pedigree which had presented at Jiaxing Maternity and Child Health Care Hospital on August 31, 2021 was selected as the study subject, for which chromosomal karyotyping, single nucleotide polymorphism-based microarray (SNP-array), and fluorescence in situ hybridization (FISH) were carried out in combination. RESULTS: SNP-array analysis showed that the proband and his sister had both harbored a 16.1 Mb duplication which encompassed the critical region of 15q26 overgrowth syndrome. FISH confirmed that the proband was 47,XX,+neo(15)(qter→q25.3:)mat, her mother was 47,XX,del(15)(q25.3:),+neo(15)(qter→q25.3:), whilst her father was normal. CONCLUSION Application of multiple genetic techniques has facilitated delineation of the origin of sSMC and reliable genetic counseling for this pedigree.
Female ; Humans ; Chromosomes ; East Asian People ; In Situ Hybridization, Fluorescence ; Karyotyping ; Pedigree ; Polymorphism, Single Nucleotide ; Intellectual Disability/genetics* ; Chromosome Duplication/genetics* ; Male

OBJECTIVE: To carry out genetic analysis for a fetus with confined placental mosaicism (CPM) for trisomy 2 (T2) in conjunct with fetal uniparental disomy (UPD). METHODS: Amniocentesis and chromosomal karyotyping was carried out for a pregnant woman with a high risk for chromosome 2 anomalies indicated by non-invasive prenatal testing (NIPT). Single nucleotide polymorphism array (SNP-array) and trio-whole exome sequencing (Trio-WES) were carried out. Ultrasonography was used to closely monitor the fetal growth. Multifocal sampling of the placenta was performed after delivery for copy number variation sequencing (CNV-seq). RESULTS: The fetus was found to have a normal chromosomal karyotype. SNP-array has revealed multiple regions with loss of heterozygosity (LOH) on chromosome 2. Trio-WES confirmed the presence of maternal UPD for chromosome 2. Ultrasonography has revealed intrauterine growth restriction and oligohydramnios. Intrauterine fetal demise had occurred at 23⁺⁴ weeks of gestation. Pathological examination had failed to find salient visceral abnormality. The placenta was proved to contain complete T2 by CNV-seq. CONCLUSION T2 CPM can cause false positive result for NIPT and may be complicated with fetal UPD, leading to adverse obstetric outcomes such as intrauterine growth restriction, oligohydramnios and intrauterine fetal demise.
Female ; Humans ; Pregnancy ; Amniocentesis ; Chromosomes, Human, Pair 2/genetics* ; DNA Copy Number Variations ; Fetal Death ; Fetal Growth Retardation/genetics* ; Fetus ; Mosaicism ; Oligohydramnios ; Placenta ; Trisomy/genetics* ; Uniparental Disomy/genetics*

OBJECTIVE: To assess the clinical efficacy and health economic value of non-invasive prenatal testing (NIPT) for the prenatal screening of common fetal chromosomal aneuploidies. METHODS: 10 612 pregnant women from October 2017 to December 2019 presented at the antenatal screening clinic of the General Hospital of Tianjin Medical University were selected as the study subjects. Results of NIPT and invasive prenatal diagnosis and follow-up outcome for the 10 612 pregnant women were retrospectively analyzed and compared. Meanwhile, NIPT data for two periods were analyzed for assessing the health economic value of NIPT as the second- or first-tier screening strategy for the prenatal diagnosis of fetal trisomies 21, 18 and 13. RESULTS: The NIPT was successful in 10 528 (99.72%) subjects, with the sensitivity for fetal trisomies 21, 18 and 13 being 100%, 92.86% and 100%, and the positive predictive value (PPV) being 89.74%, 61.90% and 44.44%, respectively. The PPV of NIPT for sex chromosome aneuploidies was 34.21%. Except for one false negative case of trisomy 18, the negative predictive value for trisomy 21, trisomy 13 and other chromosomal abnormalities were 100%. For pregnant women with high risk by serological screening, advanced maternal age or abnormal ultrasound soft markers, NIPT has yielded a significantly increased high risk ratio. There was no statistical difference in the PPV of NIPT among pregnant women from each subgroup. NIPT would have higher health economic value as a second-tier screening until 2019, while compared to 2015 ~ 2017, its incremental cost-effectiveness ratio as a first-tier screening had declined clearly. CONCLUSION The screening efficacy of NIPT for trisomies 21, 18 and 13 for a mixed population is significantly better than conventional serological screening, but it is relatively low for sex chromosomal abnormalities. NIPT can also be recommended for populations with relatively high risks along with detailed pre- and post-test genetic counselling. From the perspective of health economics, except for open neural tube defects, it is possible for NIPT to replace the conventional serological screening in the future as its cost continues to decrease.
Pregnancy ; Female ; Humans ; Trisomy/genetics* ; Retrospective Studies ; Prenatal Diagnosis/methods* ; Down Syndrome/genetics* ; Aneuploidy ; Chromosome Aberrations ; Trisomy 18 Syndrome/genetics* ; Sex Chromosome Aberrations ; Fetus

OBJECTIVES: To study the clinical features and prognosis of high hyperdiploid (HHD) childhood acute lymphoblastic leukemia (ALL). METHODS: A retrospective analysis was performed on the medical data of 1 414 children who were newly diagnosed with ALL and were admitted to five hospitals in Fujian Province of China from April 2011 to December 2020. According to karyotype, they were divided into two groups: HHD (n=172) and non-HHD (n=1 242). The clinical features and treatment outcome were compared between the two groups, and the factors influencing the prognosis were further explored. RESULTS: Among the 1 414 children with ALL, 172 (12.16%) had HHD. Compared with the non-HHD group, the HHD group had significantly lower proportions of children with risk factors for poor prognosis at diagnosis (age of onset ≥10 years or <1 year, white blood cell count ≥50×10⁹/L, and T-cell phenotype) or positive fusion genes (TEL-AML1, BCR-ABL1, E2A-PBX1, and MLL gene rearrangement) (P<0.05). The HHD group had a significantly higher proportion of children with minimal residual disease (MRD) <0.01% at the end of induction chemotherapy (P<0.05). The 10-year event-free survival (EFS) rate and overall survival (OS) rate in the HHD group were significantly higher than those in the non-HHD group (P<0.05). The univariate analysis showed that the number of chromosomes of 58-66, trisomy of chromosome 10, trisomy of chromosome 17, bone marrow MRD <1% on day 15 or 19 of induction chemotherapy, and bone marrow MRD <0.01% on day 33 or 46 of induction chemotherapy were associated with a higher EFS rate (P<0.05), and trisomy of chromosome 10 was associated with a higher OS rate (P<0.05). The multivariate Cox analysis showed that trisomy of chromosome 17 was closely associated with a high EFS rate (P<0.05). CONCLUSIONS The ALL children with HHD have few risk factors for poor prognosis at diagnosis and often have good prognosis. The number of chromosomes and trisomy of specific chromosomes are associated with prognosis in these children.
Child ; Humans ; Retrospective Studies ; Trisomy ; Prognosis ; Treatment Outcome ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis* ; Neoplasm, Residual ; Disease-Free Survival

OBJECTIVE: To explore the genetic basis for a fetus with severe heart defect and mosaic trisomy 12, and the correlation between chromosomal abnormalities and clinical manifestations and pregnancy outcome. METHODS: A 33-year-old pregnant woman who presented at Lianyungang Maternal and Child Health Care Hospital on May 17, 2021 due to abnormal fetal heart development revealed by ultrasonography was selected as the study subject. Clinical data of the fetus were collected. Amniotic fluid sample of the pregnant women was collected and subjected to G-banded chromosomal karyotyping and chromosomal microarray analysis (CMA). The CNKI, WanFang and PubMed databases were searched with key words, with the retrieval period set as from June 1, 1992 to June 1, 2022. RESULTS: For the 33-year-old pregnant woman, ultrasonography at 22+6 gestational weeks had revealed abnormal fetal heart development and ectopic pulmonary vein drainage. G-banded karyotyping showed that the fetus has a karyotype of mos 47,XX,+12[1]/46,XX[73], with the mosaicism rate being 1.35%. CMA results suggested that about 18% of fetal chromosome 12 was trisomic. A newborn was delivered at 39 weeks of gestation. Follow-up confirmed severe congenital heart disease, small head circumference, low-set ears and auricular deformity. The infant had died 3 months later. The database search has retrieved 9 reports. Literature review suggested that the liveborn infants with mosaic trisomy 12 had diverse clinical manifestations depending on the affected organs, which had included congenital heart disease and/or other organs and facial dysmorphisms, resulting in adverse pregnancy outcomes. CONCLUSION Trisomy 12 mosaicism is an important factor for severe heart defects. The results of ultrasound examination have important value for evaluating the prognosis of the affected fetuses.
Infant, Newborn ; Child ; Pregnancy ; Female ; Humans ; Adult ; Trisomy/genetics* ; Amniocentesis/methods* ; Chromosome Disorders ; Mosaicism ; Fetus ; Heart Defects, Congenital/genetics*

OBJECTIVE: To analyze the result of prenatal diagnosis and outcome of pregnancy for fetuses with rare autosomal trisomies (RATs) suggested by non-invasive prenatal testing (NIPT). METHODS: A total of 69 608 pregnant women who underwent NIPT at Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2020 were selected as study subjects. The result of prenatal diagnosis and outcome of pregnancy for those with a high risk for RATs were retrospectively analyzed. RESULTS: Among the 69 608 pregnant women, the positive rate of NIPT for high-risk RATs was 0.23% (161/69 608), with trisomy 7 (17.4%, 28/161) and trisomy 8 (12.4%, 20/161) being the most common, and trisomy 17 (0.6%, 1/161) being the rarest. For 98 women who had accepted invasive prenatal diagnosis, 12 fetal chromosomal abnormalities were confirmed, and in 5 cases the results were consistent with those of NIPT, which yielded a positive predictive value of 5.26%. Among the 161 women with a high risk for RATs, 153 (95%) were successfully followed up. 139 fetuses were ultimately born, with only one being clinically abnormal. CONCLUSION Most women with a high risk for RATs by NIPT have good pregnancy outcomes. Invasive prenatal diagnosis or serial ultrasonography to monitor fetal growth, instead of direct termination of pregnancy, is recommended.
Pregnancy ; Female ; Humans ; Trisomy/genetics* ; Pregnancy Outcome ; Retrospective Studies ; Prenatal Diagnosis/methods* ; Fetus ; Trisomy 18 Syndrome/genetics* ; Aneuploidy