OBJECTIVE: To analyze the clinical data and results of prenatal diagnosis for fetuses with high-risk for trisomy/monosomy 13 by non-invasive prenatal testing (NIPT). METHODS: Clinical data of pregnant women with fetus at a high risk for trisomy/monosomy 13 by NIPT at the First Affiliated Hospital of Zhengzhou University from May 2016 to May 2024 were reviewed, and relevant data such as Z-score, positive predictive value (PPV) and fetal fraction (FF) were analyzed to assess the correlation between them. This study was approved by the Ethics Committee of the Hospital (No. 2018-YB-08). RESULTS: 71 fetuses were found to have a high risk by NIPT, including 58 cases for trisomy 13 (T13) and 13 cases for monosomy 13 (M13). 52 women had opted invasive prenatal diagnosis and 13 cases were confirmed, which yielded a positive prediction value (PPV) of 25%. 12 fetuses were confirmed as T13 (PPV = 29.3%; 12/41), 1 was confirmed as M13 (PPV = 9.1%; 1/11). The PPV had increased along with the Z-score. Fetal faction (FF) was not correlated with the age of woman but gestational age, and was negatively correlated with the body mass index. No statistical difference was found in FF and Z-score between true- and false-positive fetuses, and there was a weak correlation between the Z-score and FF. The PPV of the NIPT could be improved by combining the results of ultrasonography. CONCLUSION The high false positive rate for T13 may be related to confined placental mosaicism, PPV is related to the Z-score, which in turn is related to FF. High-risk women are strongly recommended to undergo genetic counseling and prenatal diagnosis. Clinicians should consider relevant information such as the age of women, gestational age, indication for prenatal screening, Z-score, PPV, and FF in order to accurately interpret the result of NIPT, reduce anxiety, and avoid direct termination of the pregnancy.
Humans ; Female ; Pregnancy ; Trisomy 13 Syndrome/genetics* ; Adult ; Prenatal Diagnosis/methods* ; Noninvasive Prenatal Testing/methods*

Objective:To explore the genetic etiology of a child with delayed growth and development and carry out a literature review.Methods:A child suspected for Al Kaissi syndrome at the First Affiliated Hospital of Zhengzhou University on March 6, 2021 was selected as the study subject. Following extraction of genomic DNA, the child was subjected to copy number variation sequencing (CNV-seq) and whole exome sequencing (WES), and candidate variants were verified by PCR-agarose gel electrophoresis and quantitative real-time PCR (qPCR). Prenatal diagnosis was conducted on chorionic villi sample upon subsequent pregnancy.Results:The child, a 6-year-and-4-month-old boy, has dysmorphic features including low-set protruding ears and triangular face, delayed language and intellectual development, and ventricular septal defect. CNV-seq result has found no obvious abnormality, whilst WES revealed homozygous deletion of exons 1 and 2 of the CDK10 gene, which was confirmed by PCR -agarose gel electrophoresis and qPCR. Both of his parents were heterozygous carriers. Prenatal diagnosis using chorionic villi samples suggested that the fetus also carried the heterozygous deletion.Conclusion:The clinical features of Al Kaissi syndrome in this child can probably be attributed to the homozygous deletion of exons 1 and 2 of the CDK10 gene.

Clinical application of serological screening and non-invasive prenatal testing (NIPT) both have difficulties to attain high detection rate and low cost. For its advantages of high detection rate, high sensitivity, simplicity, short turnaround time and low cost, digital PCR (dPCR) has provided a new choice for prenatal screening of trisomies 21, 18 and 13. To standardize the application of dPCR for prenatal screening, we have formulated this consensus by referring to relevant guidelines, expert consensus and latest literature, which has covered the basic requirements, application scope, pre-testing service, testing procedure, report interpretation, genetic counseling, and limitations for this technology.

OBJECTIVE: To summarize the results of prenatal diagnosis and outcome of pregnancy of fetuses with a high risk for 6p22.1.1-p21.32 duplication signaled by non-invasive prenatal screening (NIPS). METHODS: Clinical information, results of prenatal diagnosis and pregnancy for fetuses with a high risk for 6p22.1-p21.32 duplication were collected and analyzed. This study has been approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethic No. 2018-YB-08). RESULTS: Forty three pregnant women with a high risk for 6p22.1-p21.32 duplication were identified by NIPS, among whom 30 had accepted invasive prenatal diagnosis, and 27 fetuses were verified to be false positive. Three fetuses were found to have other chromosomal abnormalities, among whom two were rated to be likely benign CNV and 1 was rated to be likely pathogenic. Follow up of the 43 pregnant women revealed that 35 fetuses were normal after birth, 1 pregnancy was terminated, and 7 were lost to follow up. CONCLUSION For pregnant women with a high risk for 6p22.1-p21.32 duplication signaled by NIPS, genetic counselor need to inform them the high false positive rate and recommend invasive prenatal diagnosis and/or ultrasound examination in order to reduce the psychological and economic burdens.
Humans ; Female ; Pregnancy ; Chromosome Duplication ; Adult ; Prenatal Diagnosis/methods* ; Chromosomes, Human, Pair 6/genetics* ; Pregnancy Outcome ; Noninvasive Prenatal Testing/methods* ; Chromosome Disorders/genetics* ; Fetus/abnormalities*

Objective:To detect and analyze the gene variation types of 64 unrelated pedigrees affected with autosomal dominant polycystic kidney disease (ADPKD), and explore the detection efficiency of multiple gene analysis techniques and variation characteristics.Methods:It was a cross-sectional study. The clinical data of 64 pedigrees with ADPKD from Nephrology Department or Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from December 2017 to August 2020 were retrospectively analyzed. The blood samples of probands and other family members were collected. Genetic analysis was carried out by next generation sequencing, and suspected mutations were verified by multiplex ligation-dependent probe amplification, or long-range PCR combined with Sanger sequencing. Prenatal diagnosis for high-risk fetuses was performed by fetal villi or amniotic fluid cells after genotyping without maternal genomic DNA contamination.Results:Among detected 64 pedigrees, 57 pedigrees (89.06%) had genetic variants in PKD1/PKD2. A total of 49 pathogenic/likely pathogenic variants in PKD1/PKD2 were identified in 51 pedigrees (79.69%), including 14 nonsense variants (28.57%), 14 frameshift variants (28.57%), 11 missense variants (22.45%), 5 splicing variants (10.20%) and 5 deletion variants (10.20%). Of these variants, 87.76% (43/49) were in PKD1 and 12.24% (6/49) were in PKD2. Totally, 14 novel variants in PKD1/ PKD2 were identified, including 7 frameshift variants, 3 splicing variants, 2 nonsense variants, 1 deletion variant and 1 missense variant, of which 11 variants were in PKD1 and 3 variants were in PKD2. Twenty high-risk fetuses from 17 pedigrees received prenatal diagnosis, in whom 6 fetuses had PKD1 variation, and other 14 fetuses had no PKD1/ PKD2-genetic variation. Conclusions:The combination of next-generation sequencing, multiplex ligation-dependent probe amplification, and long-range PCR combined with Sanger sequencing can be helpful for rapid, efficient and accurate genetic diagnosis of ADPKD pedigrees. Point mutations are the most common types in PKD1/PKD2. Fourteen novel variants in PKD1/PKD2 extend its pathogenic variant spectrum and can provide basis for genetic counseling and prenatal diagnosis of ADPKD pedigrees.

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

OBJECTIVE: To explore the genetic etiology for a Chinese pedigree affected with Meckel syndrome. METHODS: A pedigree with a history of three consecutive adverse pregnancies which presented at the First Affiliated Hospital of Zhengzhou University on August 31, 2017 was selected as the study subject. Clinical data of the pedigree were collected. High-throughput sequencing was carried out to screen for variants of ciliopathy-related genes in the third fetus following induced abortion, and candidate variant was verified by Sanger sequencing. RESULTS: The first pregnancy of the couple had ended as spontaneous abortion, whilst the fetus of the second pregnancy was suspected for having ciliopathy, though no genetic testing was carried out following elected abortion. The fetus of the third pregnancy was suspected for having ciliopathy, and high-throughput sequencing and Sanger sequencing had shown that the fetus had harbored compound heterozygous variants of the TMEM67 gene, including c.978+1G>A from the father and c.1288G>C (p.D430H) from the mother. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.978+1G>A was classified as a pathogenic variant (PVS1+PM2_Supporting+PP5), whilst the newly discovered c.1288G>C (p.D430H) was classified as a likely pathogenic variant (PM2_Supporting+PM3+PM5+PP3). CONCLUSION The c.978+1G>A and c.1288G>C (p.D430H) compound heterozygous variants of the TMEM67 gene probably underlay the three consecutive adverse pregnancies suspected for ciliopathy in this pedigree. The discovery of c.1288G>C (p.D430H) has also expanded the mutational spectrum of the TMEM67 gene.
Female ; Pregnancy ; Humans ; Pedigree ; East Asian People ; Ciliary Motility Disorders/genetics* ; Ciliopathies ; Abortion, Spontaneous ; Membrane Proteins/genetics*

OBJECTIVE: To explore the cause for a twin pregnancy with false negative result for 22q11.2 deletion syndrome by expanded non-invasive prenatal testing (NIPT-plus). METHODS: A pregnant woman with twin pregnancy through in-vitro fertilization and negative result of NIPT-plus was selected as the study subject. Amniocentesis was conducted after ultrasonic finding of fetal abnormalities. In addition to conventional G-banded karyotyping, copy number variation sequencing (CNV-Seq) was used to detect chromosomal microdeletion and microduplication. Clinical data of the woman were analyzed to explore the reasons underlying the false negative result. RESULTS: NIPT-plus has yielded a negative result with 11.77 Mb unique reads and 3.05% fetal fraction. Both fetuses had a normal karyotype (46,XY and 46,XX). CNV-seq indicated that one of the fetuses was normal, whilst the other was diagnosed with a 2.58 Mb deletion in the 22q11.2 region. CONCLUSION The false negative result may be attributed to the combined influence of low fetal fraction, high BMI, twin pregnancy through IVF and a relatively small deletion fragment. Ultrasonography exam following a low-risk result of NIPT-plus should not be neglected.
Pregnancy ; Female ; Humans ; Prenatal Diagnosis ; Pregnancy, Twin/genetics* ; DiGeorge Syndrome/genetics* ; DNA Copy Number Variations ; Amniocentesis

Objective:To explore the genetic etiology of a child with suspected propionic acidemia.Methods:Genomic DNA was extracted from peripheral blood sample of the child and subjected to high-throughput sequencing to screen pathogenic variants of genes associated with methylmalonic acidemia and propionic acidemia, including MUT, MMACHC, MMAA, MMAB, MMADHC, LMBRD1, PCCA, PCCB and SLC22A5. Candidate variants were verified by Sanger sequencing of the proband, her parents and sister. Results:The proband was found to harbor two pathogenic variants of the MUT gene, namely c. 1560+ 2T>C and c. 729_730insTT (p.Asp244fs), but not in genes associated with propionic acidemia. Her sister and father had carried c. 1560+ 2T>C, and her mother had carried c. 729_730insTT (p.Asp244fs). Conclusion:The proband was diagnosed as methylmalonic acidemia due to compound heterozygous variants of c. 1560+ 2T>C and c. 729_730insTT (p.Asp244fs) of the MUT gene. Her elder sister and parents were all carriers. Genetic testing has facilitated differential diagnosis of methylmalonic acidemia and propionic acidemia in this pedigree.

OBJECTIVE: To assess the value of re-sampling for patients who had failed non-invasive prenatal testing (NIPT) due to low cell-free fetal DNA (cffDNA) fraction. METHODS: Clinical data of 20 387 patients undergoing NIPT test was reviewed. The patients were re-sampled when initial blood test did not yield a result due to cffDNA fraction. The results were analyzed, and the outcome of pregnancy was followed up. RESULTS: Among all samples, 17 (0.08%) had failed to yield a result due to low cffDNA fraction, all of which accepted re-sampling. A result was attained in 16 cases, with a success rate of 94.12%. Only one sample had failed the re-test. CONCLUSION For patients who had failed the initial NIPT due to low cffDNA fraction, re-sampling should be considered with gestational week and ultrasound results taken into consideration.
Aneuploidy ; Cell-Free Nucleic Acids/genetics* ; DNA/genetics* ; Female ; Fetus ; Humans ; Pregnancy ; Prenatal Diagnosis