OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) and trio-whole exome sequencing (trio-WES) for fetuses with increased nuchal translucency (NT) thickness. METHODS: Sixty two pregnant women who had visited Urumqi Maternal and Child Care Health Hospital between June 2018 and June 2020 for NT ≥ 3.0 mm at 11 ~ 13⁺⁶ gestational weeks were selected as study subjects. Relevant clinical data were collected. The patients were divided into 3.0 ~ ＜3.5 mm (n = 33) and ≥3.5 mm groups (n = 29). Chromosome karyotyping analysis and chromosomal microarray analysis were carried out. And trio-WES analysis was performed on 15 samples with NT thickening but negative CMA results. The distribution and incidence of chromosomal abnormalities in the two groups were compared by using chi-square test. RESULTS: The median age of the pregnant women was 29 years old (22 ~ 41 years old), the median thickness of NT was 3.4 mm (3.0 ~ 9.1 mm), and the median gestational age at the detection was 13⁺⁴ weeks (11⁺⁵ ~ 13⁺⁶ weeks). Chromosome karyotyping analysis has detected 12 cases of aneuploidies and 1 case of derivative chromosome. The detection rate was 20.97% (13/62). CMA has detected 12 cases of aneuploidies, 1 case of pathogenic CNV and 5 cases of variant of uncertain significance (VUS), with a detection rate of 29.03% (18/62). The aneuploidy rate for the NT ≥ 3.5 mm group was higher than that for the 3.0 ≤ NT < 3.5 mm group [3.03% (1/33) vs. 41.38% (12/29), χ² = 13.698, P < 0.001]. There was no statistically significant difference between the two groups in the detection rate of fetal pathogenic CNV and VUS (χ² = 0.028, P > 0.05). Trio-WES analysis of 15 samples with negative CMA result and no structural abnormality has identified 6 heterozygous variants, including SOS1: c.3542C>T (p.A1181V) and c.3817C>G (p.L1273V), COL2A1: c.436C>T (p.P146S) and c.3700G>A (p.D1234N), LZTR1: c.1496T>C (p.V499A), and BRAF: c.64G>A (p.D22N), respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), all of the variants were rated as VUS. CONCLUSION NT thickening can indicate chromosome abnormality, and CMA and trio-WES may be used for the prenatal diagnosis.
Pregnancy ; Humans ; Female ; Adult ; Infant ; Nuchal Translucency Measurement/methods* ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Aneuploidy ; Fetus/diagnostic imaging* ; Ultrasonography, Prenatal ; DNA Copy Number Variations ; Transcription Factors

OBJECTIVE: To explore the prenatal ultrasonographic features and genetic basis for an abortus suspected for type II Cornelia de Lange syndrome (CdLS2). METHODS: A fetus diagnosed with CdLS2 at the Shengjing Hospital Affiliated to China Medical University on September 3, 2019 was selected as the study subject. Clinical data of the fetus and family history was collected. Following induced labor, whole exome sequencing was carried out on the abortus. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: Prenatal ultrasonography (33 weeks of pregnancy) has revealed multiple anomalies in the fetus, which included slightly widened cavity of septum pellucidum, blurred corpus callosum, slightly reduced frontal lobe volume, thin cortex, fusion of lateral ventricles, polyhydramnios, small stomach bubble, and digestive tract atresia. Whole exome sequencing has revealed a heterozygous c.2076delA (p.Lys692Asnfs*27) frameshifting variant in the SMC1A gene, which was found in neither parent and was rated as pathogenic based on the guidelines of American College of Medical Genetics and Genomics (ACMG). CONCLUSION The CdLS2 in this fetus may be attributed to the c.2076delA variant of the SMC1A gene. Above finding has provided a basis for genetic counseling and assessment of reproductive risk for this family.
Pregnancy ; Female ; Humans ; Cell Cycle Proteins/genetics* ; De Lange Syndrome/diagnosis* ; Phenotype ; Ultrasonography, Prenatal ; Fetus/diagnostic imaging* ; Mutation

OBJECTIVE: To explore the clinical phenotype and genetic variants of a fetus with Glutaracidemia type II C (GA II C). METHODS: Clinical data of a 32-year-old pregnant woman and her fetus with GA II C diagnosed at the Third Affiliated Hospital of Zhengzhou University in December 2021 due to the enlargement and enhanced echo of the kidneys and oligohydramnios fluid at 17 weeks were analyzed retrospectively. Amniotic fluid sample of the fetus and peripheral blood samples of the couple were collected for whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Copy number variation (CNV) was detected by using low-coverage whole genome sequencing (CNV-seq). RESULTS: At 18 weeks' gestation, ultrasound revealed that the fetus had enlargement and enhanced echo of the kidneys along with no echo of renal parenchymal tubular fissure and oligohydramnios. MRI at 22 weeks' gestation confirmed that both kidneys were enlarged with uniformly increased abnormal T2 signal and decreased DWI signal. The volume of both lungs was small, with slightly higher T2 signal. No CNV was detected in the fetus. WES revealed that the fetus has harbored compound heterozygous variants of the ETFDH gene, namely c.1285+1G＞A and c.343_344delTC, which were inherited from its father and mother, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as pathogenic (PVS1+PM2_Supporting+PS3_Supporting; PVS1+PM2_Supporting+PM3). CONCLUSION The c.1285+1G＞A and c.343_344delTC compound heterozygous variants of the ETFDH gene probably underlay the disease in this fetus. Type II C glutaric acidemia may manifest as bilateral kidney enlargement with enhanced echo and oligohydramnios. Discovery of the c.343_344delTC has enriched the spectrum of ETFDH gene variants.
Pregnancy ; Humans ; Female ; Mutation ; DNA Copy Number Variations ; Oligohydramnios/genetics* ; Retrospective Studies ; Phenotype ; Fetus/diagnostic imaging*

OBJECTIVE: To investigate the perinatal clinical phenotype and genetic characteristics of two fetuses with ring chromosome 21 mosaicisms. METHODS: Two fetuses who were diagnosed at the Xiamen Maternal and Child Health Care Hospital in November 2021 were selected as the study subjects. Clinical data of the two fetuses were collected. Conventional G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out for the fetuses and their parents. RESULTS: Prenatal ultrasonography of fetus 1 has revealed absence of nasal bone, ventricular septal defect, persistent left superior vena cava, and mild tricuspid regurgitation. Chromosomal karyotyping was 46,X?,dic r(21;21)(p12q22;q22p12)[41]/45,X?,-21[9]. CMA has revealed a 30.00 Mb quadruplication at 21q11.2q22.3 and a 3.00 Mb deletion at 21q22.3. For fetus 2, ultrasonography has revealed pointed echo of the nasal bone. The fetus was found to have a karyotype of 46,X?,r(21)(p12q22)[83]/45,X?,-21[14]/46,X?,dic r(21;21)(p12q22;q22p12)[3]. CMA has revealed a 5.10 Mb quadruplication at 21q22.12q22.3 and a 2.30 Mb deletion at 21q22.3. CONCLUSION The perinatal phenotype of the two fetuses with ring chromosome 21 mosaicisms is related to the duplication of chromosomal segments near the breakpoints of the chromosomal deletions. The combined chromosomal karyotyping and CMA has enabled prenatal diagnosis and genetic counseling for these families.
Pregnancy ; Female ; Humans ; Mosaicism ; Ring Chromosomes ; Vena Cava, Superior ; Chromosome Aberrations ; Prenatal Diagnosis ; Microarray Analysis ; Fetus/diagnostic imaging*

OBJECTIVE: To explore the genetic basis for three fetuses with duodenal atresia or stenosis detected by ultrasonography. METHODS: Clinical data of three fetuses identified at the Women's Hospital Affiliated to Zhejiang University School of Medicine between January 2021 and August 2022 were collected. Umbilical cord blood and amniotic fluid samples of the fetuses and peripheral blood samples of their parents were collected and subjected to G-banded chromosomal karyotyping and single nucleotide polymorphism array (SNP array) analysis. RESULTS: Prenatal ultrasound of the three fetuses revealed duodenal atresia or stenosis. No karyotypic abnormality was detected, whilst SNP array has identified 1.4 ~ 1.9 Mb duplications at 17q12 in all of them, which were all predicted to be pathogenic copy number variations (CNVs). CONCLUSION The 17q12 duplications probably underlay the duodenal atresia and stenosis in these fetuses, and chromosomal CNVs should be considered in duodenal atresia and stenosis.
Pregnancy ; Humans ; Female ; DNA Copy Number Variations ; Constriction, Pathologic ; Prenatal Diagnosis ; Fetus/diagnostic imaging* ; Chromosome Aberrations

OBJECTIVE: To analyze the ultrasonographic phenotype and result of genetic testing in six fetuses carrying a 17q12 microdeletion. METHODS: Chromosomal microarray analysis (CMA) was carried out for 6200 pregnant women undergoing prenatal diagnosis from December 2016 to May 2021. RESULTS: CMA has identified 6 fetuses with a microdeletion in the 17q12 region, which spanned approximately 1.4 Mb and encompassed at least 13 OMIM genes. All fetuses have shown bilateral renal parenchymal echo enhancement. Four fetuses also had other ultrasonographic phenotypes. The parents of 4 fetuses had refused parental verification, whilst the remaining two fetuses were confirmed to be de novo in origin. CONCLUSION The prenatal ultrasonographic phenotype of 17q12 microdeletion is mainly enhanced bilateral renal parenchymal echos. CMA can facilitate detection of the 17q12 microdeletion.
Female ; Humans ; Pregnancy ; Genetic Testing ; Phenotype ; Fetus/diagnostic imaging* ; Prenatal Diagnosis ; Parents

OBJECTIVE: To analyze the phenotype and genetic variant of a fetus with dysplasia of cerebellar vermis. METHODS: Gestational status and family history of the gravida was taken in combination with the imaging results of the fetus. Following elected abortion, fetal tissue and peripheral blood samples of the couple were collected for the extraction of genome DNA. Whole exome sequencing was carried out to screen potential variant associated with the phenotype of the proband. Specific PCR primers were designed to verify the results by Sanger sequencing. RESULTS: Prenatal ultrasound revealed that the fetal vermis cerebellum was poorly developed, which was similar to the previous pregnancy. Whole exome sequencing revealed that the fetus has carried compound heterozygous variants of the CPLANE1 gene, namely c.7978C>T and c.7169delT, which were respectively inherited from the husband and wife. CONCLUSION The c.7978C>T and c.7169delT compound heterozygous variants of the CPLANE1 gene probably underlay the dysplasia of cerebellar vermis in the fetus, which has provided a basis for genetic counseling and prenatal diagnosis.
Abnormalities, Multiple/genetics* ; Cerebellum/diagnostic imaging* ; Eye Abnormalities/genetics* ; Female ; Fetus ; Humans ; Kidney Diseases, Cystic ; Mutation ; Phenotype ; Pregnancy ; Retina/abnormalities*

OBJECTIVE: To analyze the prenatal ultrasonic characteristics and genetic features of 14 fetuses with chromosome 22q11 microdeletion syndrome (22q11DS). METHODS: 4989 fetuses were analyzed by using single nucleotide polymorphism array (SNP array) in the Fujian Maternal and Child Health Hospital from November 2016 to November 2019. RESULTS: SNP array showed that 11 fetuses had classic 3 Mb microdeletion in 22q11 region, one fetus had 2.0 Mb microdeletion, and two fetuses had 1.0 Mb microdeletion. The 1.0 Mb microdeletion in 22q11 region contains SNAP29 and CRKL genes, which may increase the risk of congenital renal malformation and cardiovascular malformation. CONCLUSION Prenatal ultrasonic characteristics of fetuses with 22q11 microdeletion syndrome vary, and SNP array is a powerful tool to diagnose such diseases, which can provide accurate genetic diagnosis and enable prenatal diagnosis.
22q11 Deletion Syndrome/diagnostic imaging* ; Chromosome Deletion ; Chromosomes, Human, Pair 22/genetics* ; Female ; Fetus ; Genetic Testing ; Humans ; Pregnancy ; Prenatal Diagnosis ; Ultrasonics

OBJECTIVE: To investigate the application value of whole exome sequencing technology in fetuses with congenital structural abnormalities. METHODS: The chromosomal abnormalities of 1147 families were analyzed. According to the follow-up results, the data of fetuses with new phenotypes in late pregnancy or after birth were reanalyzed. Subgroups were divided according to the organs involved and whether single malformation or not. The gene regulatory network map was drawn by using string database and Cytoscape software. Fisher exact probability method was used to compare the difference of the diagnostic rate of pathogenic genes among the groups. RESULTS: A total of 160 fetal cases received positive molecular diagnosed, involving 178 variant sites of 125 pathogenic genes, including 8 cases (4.9%, 8/163) by data reanalysis, and the overall positive diagnosis rate was 13.9%. Diagnostic rate was highest in the group of skeletal malformation (31.5%, 39/124) and lowest in that with thoracic malformation (0, 0/32). The gene clusters of fetal edema and intrauterine growth restriction were independent, and were not associated with the major structural malformations. The probability of each parent carrying the same recessive gene variant was 0.03 (39/1146) and 0.08 (4/53) with positive family history. CONCLUSION For fetuses with congenital structural abnormalities that are negative for conventional genetic tests, 13.9% of phenotypic associated pathogenic/likely pathogenic genetic variants can be detected by whole exome sequencing technology. Its application value for prenatal diagnosis varies in fetus with different organs involved. Reanalysis of sequencing data for cases with new phenotypes in late pregnancy or after birth can further improve the molecular diagnosis rate. Further investigations are needed to explore the related genetic mechanisms.
Female ; Fetal Diseases ; Fetus/diagnostic imaging* ; Humans ; Pregnancy ; Prenatal Diagnosis ; Technology ; Ultrasonography, Prenatal ; Whole Exome Sequencing

OBJECTIVE: To carry out genetic analysis for a family with a fetus manifesting bilateral polycystic renal dysplasia and oligohydramnios at 16 gestational week and a previous history for fetal renal anomaly. METHODS: Ultrasound scan was carried out to detect the morphological changes. Following genetic counselling, the parents had decided to terminate the pregnancy. Fetal kidneys were subjected to histological examination. Target capture and next generation sequencing (NGS) was applied to the abortus to detect potential variants. The results were verified by Sanger sequencing. RESULTS: Histological examination of fetal kidneys revealed cystic changes without cortex, medulla or normal renal structure. NGS has identified a heterozygous c.100+1G>A variant and deletion of exon 3 of the INVS gene, which were respectively inherited from the mother and father. CONCLUSION Through NGS and Sanger sequencing, the fetus was diagnosed with type II nephronophthisis (NPHP2). Above result can provide guidance for further pregnancy and enforce understanding of clinical features and genetic etiologies for NPHP.
Female ; Fetus ; Genetic Testing ; Heterozygote ; Humans ; Mutation ; Polycystic Kidney, Autosomal Dominant ; diagnostic imaging ; genetics ; Pregnancy ; Sequence Deletion ; genetics ; Transcription Factors ; genetics ; Ultrasonography