1.Report content and prenatal diagnosis of non-invasive prenatal testing for sex chromosome aneuploidy.
Chun Xiang ZHOU ; Lin Lin HE ; Xiang Yu ZHU ; Zhao Xia LI ; Hong Lei DUAN ; Wei LIU ; Lei Lei GU ; Jie LI
Chinese Journal of Obstetrics and Gynecology 2023;58(10):766-773
Objective: To analyze the report content, the methods and results of prenatal diagnosis of high risk of sex chromosome aneuploidy (SCA) in non-invasive prenatal testing (NIPT). Methods: A total of 227 single pregnancy pregnant women who received genetic counseling and invasive prenatal diagnosis at Drum Tower Hospital Affiliated to the Medical School of Nanjing University from January 2015 to April 2022 due to the high risk of SCA suggested by NIPT were collected. The methods and results of prenatal diagnosis were retrospectively analyzed, and the results of chromosome karyotype analysis and chromosome microarray analysis (CMA) were compared. The relationship between NIPT screening and invasive prenatal diagnosis was analyzed. Results: (1) Prenatal diagnosis methods for 277 SCA high risk pregnant women included 73 cases of karyotyping, 41 cases of CMA and 163 cases of karyotyping combined with CMA, of which one case conducted amniocentesis secondly for further fluorescence in situ hybridization (FISH) testing. Results of invasive prenatal diagnosis were normal in 166 cases (59.9%, 166/277), and the abnormal results including one case of 45,X (0.4%, 1/277), 18 cases of 47,XXX (6.5%, 18/277), 36 cases of 47,XXY (13.0%, 36/277), 20 cases of 47,XYY (7.2%, 20/277), 1 case of 48,XXXX (0.4%, 1/277), 20 cases of mosaic SCA (7.2%, 20/277), 5 cases of sex chromosome structural abnormality or large segment abnormality (1.8%, 5/277), and 10 cases of other abnormalities [3.6%, 10/277; including 9 cases of copy number variation (CNV) and 1 case of balanced translocation]. Positive predictive value (PPV) for SCA screening by NIPT was 34.7% (96/277). (2) Among the 163 cases tested by karyotyping combined with CMA, 11 cases (6.7%, 11/163) showed inconsistent results by both methods, including 5 cases of mosaic SCA, 1 case of additional balanced translocation detected by karyotyping and 5 cases of additional CNV detected by CMA. (3) NIPT screening reports included 149 cases of "sex chromosome aneuploidy"(53.8%, 149/277), 54 cases of "number of sex chromosome increased" (19.5%, 54/277), and 74 cases of "number of sex chromosome or X chromosome decreased" (26.7%, 74/277). The PPV of "number of sex chromosome increased" and "number of sex chromosome or X chromosome decreased" were 72.2% (39/54) and 18.9% (14/74), respectively, and the difference was statistically significant (χ2=34.56, P<0.01). Conclusions: NIPT could be served as an important prenatal screening technique of SCA, especially for trisomy and mosaicism, but the PPV is comparatively low. More information of NIPT such as the specific SCA or maternal SCA might help improving the confidence of genetic counseling and thus guide clinic management. Multi technology platforms including karyotyping, CMA and FISH could be considered in the diagnosis of high risk of SCA by NIPT.
Female
;
Pregnancy
;
Humans
;
Retrospective Studies
;
DNA Copy Number Variations
;
In Situ Hybridization, Fluorescence
;
Aneuploidy
;
Prenatal Diagnosis/methods*
;
Sex Chromosome Aberrations
;
Sex Chromosomes/genetics*
2.Accidental discovery of copy number variation on chromosome 1 in a fetus with high risk of trisomy 13 suggested by NIPT.
Jiazhen CHANG ; Yingna SONG ; Qingwei QI ; Na HAO ; Juntao LIU
Chinese Journal of Medical Genetics 2023;40(8):922-927
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*
3.Retrospective analysis of cell-free fetal DNA prenatal testing of maternal peripheral blood.
Youhua WEI ; Rui WANG ; Meixia XI ; Li WEI ; Wenjuan ZHU ; Yan LIU
Chinese Journal of Medical Genetics 2023;40(8):933-938
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*
4.The value of combined CNV-Seq and chromosomal karyotyping for the detection of amniocytic mosaicisms and a literature review.
Panlai SHI ; Ruonan ZHU ; Junhong ZHAO ; Xiangdong KONG
Chinese Journal of Medical Genetics 2023;40(8):954-959
OBJECTIVE:
To assess the value of combined copy number variation sequencing (CNV-seq) and chromosomal karyotyping for the diagnosis of amniocytic mosaicisms, in addition with a literature review.
METHODS:
Forty cases of amniocytic mosaicisms detected at the Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2021, in addition with 245 mosaicisms retrieved from 11 recent literature were evaluated in terms of detection rate, consistency rate, and pregnancy outcomes.
RESULTS:
The detection rate of amniocytic mosaicisms was 0.46% (40/8 621) in our center. And its consistency rate with chromosomal karyotyping was 75.0% (30/40). After genetic counseling, 30 (75.0%) couples had opted to terminate the pregnancy, 5 (12.5%) had decided to continue with the pregnancy, 3 (7.5%) fetuses were born alive, and 2 cases (5.0%) were lost in touch. By contrast, 245 cases (0.39%) of mosaicisms were identified among 63 577 amniotic samples, with a consistency rate of 62.8% (103/164) with other techniques. Among these, 114 cases (55.1%) were terminated, 75 (36.2%) were born alive, and 18 (8.7%) were lost during the follow up.
CONCLUSION
Combined CNV-seq and chromosomal karyotyping has a high value for the detection of amniotic mosaicisms.
Pregnancy
;
Female
;
Humans
;
Mosaicism
;
Chromosome Disorders/genetics*
;
DNA Copy Number Variations
;
Chromosome Aberrations
;
Karyotyping
;
Prenatal Diagnosis/methods*
5.Prenatal genetic diagnosis of a case with ring chromosome 13.
Lu SUN ; Juan WEN ; Guoming CHU ; Guangrui LAI ; Rong HE
Chinese Journal of Medical Genetics 2023;40(12):1455-1460
OBJECTIVE:
To carry out cyto- and molecular genetic analysis for a fetus with a ring chromosome identified through non-invasive prenatal testing (NIPT).
METHODS:
A pregnant woman presented at the Shengjing Hospital Affiliated to China Medical University on May 11, 2021 was selected as the study subject. Maternal peripheral blood sample was screened by NIPT, and G-banded chromosomal karyotyping was carried out on amniotic fluid and peripheral blood samples from the couple. The fetus and the pregnant woman were also subjected to genomic copy number variation sequencing (CNV-seq), chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH) assay.
RESULTS:
NIPT result suggested that the fetus had monomeric mosaicism or fragment deletion on chromosome 13. G banded chromosomal analysis showed that both the fetus and its mother had a karyotype of 47,XX,der(13)(pter→p11::q22→q10),+r(13)(::p10::q22→qter::), whilst her husband had a normal karyotype. FISH has verified the above results. No abnormality was detected with CNV-seq and CMA in both the fetus and the pregnant woman.
CONCLUSION
The ring chromosome 13 in the fetus has derived from its mother without any deletion, duplication and mosaicism. Both the fetus and the pregnant woman were phenotypically normal.
Humans
;
Pregnancy
;
Female
;
Ring Chromosomes
;
Chromosomes, Human, Pair 13/genetics*
;
In Situ Hybridization, Fluorescence
;
DNA Copy Number Variations
;
Prenatal Diagnosis/methods*
;
Amniotic Fluid
6.Clinical characteristics of cardiac defects fetuses and the impact of multi-disciplinary team cooperation approach on the pregnancy decision making.
Chinese Journal of Obstetrics and Gynecology 2023;58(5):326-333
Objective: To analysis the clinical characteristics of 400 fetuses with heart defects and the impactors of pregnancy decision making, and explore the influence of a multi-disciplinary team (MDT) cooperation approach on it. Methods: Clinical data of 400 fetuses with abnormal cardiac structure diagnosed at Peking University First Hospital from January 2012 to June 2021 were collected, which were divided into 4 groups according to the characteristics of fetal heart defects and the presence of extracardiac abnormalities or not: single cardiac defects without extracardiac abnormalities (122 cases), multiple cardiac defects without extracardiac abnormalities (100 cases), single cardiac defects with extracardiac abnormalities (115 cases), and multiple cardiac defects with extracardiac abnormalities (63 cases). The types of fetal cardiac structural abnormalities and genetic test results, and the detection rate of pathogenic genetic abnormalities, MDT consultation and management situation, and pregnancy decision of fetuses in each group were retrospectively analyzed. A logistics regression was used to analyze the influencing factors of fetal heart defects pregnancy decision. Results: (1) Among the 400 fetal heart defects, the four most common major types were ventricular septal defect 96 (24.0%, 96/400), tetralogy of Fallot 52 (13.0%, 52/400), coarctation of the aorta 34 (8.5%, 34/400), and atrioventricular septal defect 26 (6.5%, 26/400). (2) Among the 204 fetuses undergoing genetic examination, 44 (21.6%, 44/204) pathogenic genetic abnormalities were detected. (3) Detection rate of pathogenic genetic abnormalities (39.3%, 24/61) and pregnancy termination rate (86.1%, 99/115) in the single cardiac defects with extracardiac abnormalities group were significantly higher than those in the single cardiac defects without extracardiac abnormalities group [15.1% (8/53), 44.3% (54/122), respectively] and the multiple cardiac defects without extracardiac abnormalities group [6.1% (3/49), 70.0% (70/100), respectively, both P<0.05], and the pregnancy termination rate in the multiple cardiac defects without extracardiac abnormalities group and the multiple cardiac defects with extracardiac abnormalities group (82.5%,52/63) were significantly higher than that of the single cardiac abnormalities without extracardiac abnormalities group (both P<0.05). (4) After adjusting for age, gravity, parity and performed prenatal diagnosis, maternal age, the diagnosis of gestational age, prognosis grades, co-existence of extracardiac abnormalities, presence of pathogenic genetic abnormalities, and receiving MDT consultation and management were still independent influencing factors of termination of pregnancy of fetuses with cardiac defects (all P<0.05). A total of 29 (7.2%, 29/400) fetal cardiac defects received MDT consultation and management, and compared with those without MDT management, the pregnancy termination rate in the multiple cardiac defects without extracardiac abnormalities group [74.2%(66/89) vs 4/11] and the multiple cardiac defects with extracardiac abnormalities group [87.9%(51/58) vs 1/5] were lower, the differences were statistically significant respectively (all P<0.05). Conclusions: Maternal age, diagnosed gestational age, severity of cardiac defects, extracardiac abnormalities, pathogenic genetic abnormalities and MDT counseling and management are the influencing factors of fetal heart defects pregnancy decision. MDT cooperation approach influences pregnancy decision-making and should be recommended for the management of fetal cardiac defect to reduce unnecessary termination of pregnancy and improve pregnancy outcomes.
Pregnancy
;
Female
;
Humans
;
Retrospective Studies
;
Fetal Diseases/diagnosis*
;
Heart Defects, Congenital/therapy*
;
Fetus
;
Decision Making
;
Ultrasonography, Prenatal/methods*
7.Genetic analysis and reproductive intervention of 7 families with gonadal mosaicism for Duchenne muscular dystrophy.
Bodi GAO ; Xiaowen YANG ; Xiao HU ; Wenbing HE ; Xiaomeng ZHAO ; Fei GONG ; Juan DU ; Qianjun ZHANG ; Guangxiu LU ; Ge LIN ; Wen LI
Chinese Journal of Medical Genetics 2023;40(4):423-428
OBJECTIVE:
To explore the genetic basis for 7 families with gonadal mosaicism for Duchenne muscular dystrophy (DMD).
METHODS:
For the 7 families presented at the CITIC Xiangya Reproductive and Genetic Hospital from September 2014 to March 2022, clinical data were collected. Preimplantation genetic testing for monogenic disorders (PGT-M) was carried out for the mother of the proband from family 6. Peripheral venous blood samples of the probands, their mothers and other patients from the families, amniotic fluid samples from families 1 ~ 4 and biopsied cells of embryos cultured in vitro from family 6 were collected for the extraction of genomic DNA. Multiplex ligation-dependent probe amplification (MLPA) was carried out for the DMD gene, and short tandem repeat (STR)/single nucleotide polymorphism (SNP)-based haplotypes were constructed for the probands, other patients, fetuses and embryos.
RESULTS:
The results of MLPA showed that the probands and the fetuses/probands' brothers in families 1 ~ 4, 5, 7 had carried the same DMD gene variants, whilst the probands' mothers were all normal. The proband in family 6 carried the same DMD gene variant with only 1 embryo (9 in total) cultured in vitro, and the DMD gene of the proband's mother and the fetus obtained through the PGT-M were normal. STR-based haplotype analysis showed that the probands and the fetuses/probands' brothers in families 1 ~ 3 and 5 have inherited the same maternal X chromosome. SNP-based haplotype analysis showed that the proband from family 6 has inherited the same maternal X chromosome with only 1 embryo (9 in total) cultured in vitro. The fetuses in families 1 and 6 (via PGT-M) were both confirmed to be healthy by follow up, whilst the mothers from families 2 and 3 had chosen induced labor.
CONCLUSION
Haplotype analysis based on STR/SNP is an effective method for judging gonad mosaicism. Gonad mosaicisms should be suspected for women who have given births to children with DMD gene variants but with a normal peripheral blood genotype. Prenatal diagnosis and reproductive intervention may be adapted to reduce the births of further affected children in such families.
Male
;
Pregnancy
;
Child
;
Humans
;
Female
;
Muscular Dystrophy, Duchenne/diagnosis*
;
Dystrophin/genetics*
;
Mosaicism
;
Exons
;
Prenatal Diagnosis/methods*
;
Nucleotides
8.Follow-up of fetuses with de novo copy number variations of unknown significance detected by chromosomal microarray analysis.
Leilei GU ; Wei LIU ; Chunxiang ZHOU ; Peixuan CAO ; Xiangyu ZHU ; Jie LI
Chinese Journal of Medical Genetics 2023;40(4):442-445
OBJECTIVE:
To analyze the prognosis of fetuses identified with de novo variants of unknown significance (VOUS) by chromosome microarray analysis (CMA).
METHODS:
A total of 6 826 fetuses who underwent prenatal CMA detection at the Prenatal Diagnosis Center of Drum Tower Hospital from July 2017 to December 2021 were selected as the study subjects. The results of prenatal diagnosis, and outcome of fetuses identified with VOUS of de novo origin were followed up.
RESULTS:
Among the 6 826 fetuses, 506 have carried VOUS, of which 237 were detected for the parent-of-origin and 24 were found to be de novo. Among the latters, 20 were followed up for 4 to 24 months. Four couples had opted elective abortion, 4 had developed clinical phenotypes after birth, and 12 were normal.
CONCLUSION
Fetuses with VOUS should be continuously follow-up, in particular those carrying de novo VOUS, in order to clarify their clinical significance.
Pregnancy
;
Female
;
Humans
;
DNA Copy Number Variations
;
Follow-Up Studies
;
Prenatal Diagnosis/methods*
;
Chromosomes
;
Microarray Analysis/methods*
;
Fetus
;
Chromosome Aberrations
9.Genetic analysis of a Chinese pedigree with 18q21.2-q22.3 duplication and deletion in two offspring respectively resulting from a maternal intrachromosomal insertion.
Jiahong ZHOU ; Pan ZHOU ; Zhiyu LYU ; Hui ZHANG ; Qing LUO ; Lan YUAN ; Yang CHENG ; Xia WEN ; Jinbo LIU
Chinese Journal of Medical Genetics 2023;40(4):483-489
OBJECTIVE:
To provide prenatal diagnosis, pedigree analysis and genetic counseling for a pregnant woman who had given birth to a child featuring global developmental delay.
METHODS:
A pregnant woman who underwent prenatal diagnosis at the Affiliated Hospital of Southwest Medical University in August 2021 was selected as the study subject. Peripheral blood samples were collected from the woman, her husband and child, in addition with amniotic fluid sample during mid-pregnancy. Genetic variants were detected by G-banded karyotyping analysis and copy number variation sequencing (CNV-seq). Pathogenicity of the variant was predicted based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). Candidate variant was traced in the pedigree to assess the recurrence risk.
RESULTS:
The karyotypes of the pregnant woman, her fetus, and affected child were 46,XX,ins(18)(p11.2q21q22), 46,X?,rec(18)dup(18)(q21q22)ins(18)(p11.2q21q22)mat and 46,XY,rec(18)del(18)(q21q22)ins(18)(p11.2q21q22)mat, respectively. Her husband was found to have a normal karyotype. CNV-seq has revealed a 19.73 Mb duplication at 18q21.2-q22.3 in the fetus and a 19.77 Mb deletion at 18q21.2-q22.3 in her child. The duplication and deletion fragments were identical to the insertional fragment in the pregnant woman. Based on the ACMG guidelines, the duplication and deletion fragments were both predicted to be pathogenic.
CONCLUSION
The intrachromosomal insertion of 18q21.2-q22.3 carried by the pregnant woman had probably given rise to the 18q21.2-q22.3 duplication and deletion in the two offspring. Above finding has provided a basis for genetic counseling for this pedigree.
Child
;
Female
;
Humans
;
Pregnancy
;
DNA Copy Number Variations
;
East Asian People
;
Pedigree
;
Prenatal Diagnosis/methods*
;
Chromosomes, Human, Pair 18/genetics*
;
Male
;
Fetus
;
INDEL Mutation
10.Prenatal diagnosis and pregnancy outcome of fetuses with rare autosomal trisomies indicated by non-invasive prenatal testing.
Peng DAI ; Ganye ZHAO ; Shuang HU ; Ning LIU ; Xiangdong KONG
Chinese Journal of Medical Genetics 2023;40(5):513-518
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

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