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Background: An increasing number of techniques have been used for prenatal diagnosis of genetic abnormalities. Our initial objective was to explore the value of the BACs-on-Beads (BoBs) assay for the prenatal diagnosis of aneuploidies and microdeletion/microduplication syndromes in Quanzhou, Southeast China., Methods: A total of 1409 pregnant women with high-risk factors for chromosomal abnormalities admitted to Quanzhou Women's and Children's Hospital were enrolled in this study. BoBs assays and karyotype analyses were conducted for all subjects. Subsequently, chromosome microarray analysis (CMA) or fluorescence in situ hybridization (FISH) was performed to validate the findings., Results: In this study, karyotype analysis and BoBs assay failed in 4 cases, and 2 cases, respectively. A total of 1403 cases were successfully analyzed, with success rates of 99.72% (1405/1409) and 99.85% (1407/1409) for karyotype analysis and Bobs assay, respectively. BoBs assay rapidly detected chromosomal aneuploidies in line with the karyotyping data. Additionally, 23 cases of microdeletions/microduplications were detected by BoBs assay but missed by karyotyping, including 22q11.2 microdeletions/microduplications, 5p15.32p15.33 microdeletion, Xp22.31 microdeletions/microduplications, Xq27.3 microdeletion, and Yp11.2 and Yq11.22q11.222 microduplication. In comparison with karyotyping, fewer mosaicisms were identified by BoBs assay. A high detection rate of chromosomal abnormalities was observed in the high-risk group during noninvasive prenatal testing (NIPT) (41.72%) and the abnormal ultrasound group (13.43%)., Conclusions: BoBs assay can be used for the rapid and efficient prenatal diagnosis of common aneuploidies and microdeletion/microduplication syndromes. Moreover, the combined use of BoBs assay and karyotyping in prenatal diagnosis may allow for a more effective detection of chromosomal abnormalities.

Background: Causative mutations of PBX1 are associated with congenital abnormalities of the kidney and urinary tract (CAKUT), often accompanied by hearing loss, abnormal ear morphology, or developmental delay. The aim of the present investigation was to introduce a novel variant in the PBX1 gene identified in a Chinese family, leading to recurrent neonatal mortality. Methods: A pregnant woman (gravida 5, para 0), who had experienced recurrent neonatal deaths, sought genetic etiology diagnosis. Whole exome sequencing (WES) was conducted to identify sequence variants and copy number variants in the fetus presenting with posterior nuchal cystic hygroma and fetal hydrops. Results: A novel NM_002585.4:c.694G>C(p.D232H) in PBX1 was identified in the fetus through trio whole exome sequencing (WES), revealing a paternal mosaic PBX1 variant in blood at 11.54% (6/52 variants reads). Subsequent parental Sanger sequencing confirmed the variant detected by WES. Ultimately, the variant was classified as likely pathogenic, leading the family to elect pregnancy termination at 17 weeks gestation. Conclusion: The novel variant in the PBX1 gene appears to be a significant factor contributing to recurrent neonatal deaths in the Chinese family. Such findings expand the spectrum of PBX1 gene variants and provide valuable perinatal guidance for diagnosing fetuses with PBX1 mutations. [ABSTRACT FROM AUTHOR]

Few existing reports have investigated the copy number variants (CNVs) in fetuses with central nervous system (CNS) anomalies. To gain further insights into the genotype–phenotype relationship, we conducted chromosomal microarray analysis (CMA) to reveal the pathogenic CNVs (pCNVs) that were associated with fetal CNS anomalies. We enrolled 5,460 pregnant women with different high-risk factors who had undergone CMA. Among them, 57 subjects with fetal CNS anomalies were recruited. Of the subjects with fetal CNS anomalies, 23 were given amniocentesis, which involved karyotype analysis and CMA to detect chromosomal abnormalities. The other 34 cases only underwent CMA detection using fetal abortive tissue. In this study, we identified five cases of chromosome aneuploid and nine cases of pCNVs in the fetuses, with a chromosomal aberration detection rate of 24.56% (14/57). In the 23 cases that were given both karyotype and CMA analysis, one case with trisomy 18 was detected by karyotyping. Moreover, CMA revealed a further three cases of pCNVs, including the 1p36.33p36.31, 7q11.23, and 1q21.1q21.2 microdeletions, with a 13.04% (3/23) increase in CMA yield over the karyotype analysis. Additionally, three cases of trisomy 13, one case of trisomy 21, and six cases of pCNVs were detected in the other 34 fetuses where only CMA was performed. Furthermore, a higher chromosomal aberration detection rate was observed in the extra CNS anomaly group than in the isolated CNS anomaly group (40.91% vs 14.29%). In conclude, several pathogenic CNVs were identified in the fetuses with CNS anomalies using CMA. Among the detected CNVs, ZIC2, GNB1, and NSUN5 may be the candidate genes that responsible for fetal CNS anomalies. Our findings provides an additional reference for genetic counseling regarding fetal CNS anomalies and offers further insight into the genotype–phenotype relationship. [ABSTRACT FROM AUTHOR]

Background: Pathogenic mutations in EVC or EVC2 gene can lead to Ellis‐van Creveld (EvC) syndrome, which is a rare autosomal recessive skeletal dysplasia disorder. This study aimed to determine pathogenic gene variations associated with EvC syndrome in fetuses showing ultrasound anomalies. Methods: A 32‐year‐old pregnant woman from Quanzhou, China was investigated. In her pregnancy examination, the fetus exhibited multiple fetal malformations, including a narrow thorax, short limbs, postaxial polydactyly, cardiac malformations, and separation of double renal pelvis. Karyotype, chromosomal microarray analysis and whole exome sequencing were performed for prenatal genetic etiology analysis. Results: Chromosome abnormalities and copy number variants were not observed in the fetus using karyotype and chromosomal microarray analysis. Using whole exome sequencing, two compound heterozygous variants NM_147127.5:c.[2484G>A(p.Trp828Ter)];[871‐2_894del] in EVC2 gene were identified in the fetus as pathogenic variants inherited from parents. Conclusions: The study is the first to identify two rare compound variants in EVC2 gene in a Chinese family using whole exome sequencing. The application of whole‐exome sequencing would be helpful in fetal etiological diagnosis with ultrasound anomalies. [ABSTRACT FROM AUTHOR]

Background: Oculofaciocardiodental (OFCD) syndrome is an X-linked dominant syndrome caused by BCOR variants , which manifests only in females and presumed leading to male lethality. Herein, we aim to present a prenatal diagnosis for OFCD syndrome associated with a novel hemizygous variant in BCOR gene. Case presentation: A 29-year-old pregnant woman from Quanzhou Fujian Province, China, with fetal ultrasound anomalies, was enrolled in this study. A normal 46, XY karyotype with no abnormalities was observed in the fetus detected on microarray. Furthermore, a whole-exome sequencing (WES) detection result demonstrated that a novel hemizygous variant of c.251dupT (p.N87Kfs*6) in the BCOR gene was identified in the fetus, which was a frameshift mutation and classified as a likely pathogenic variant, and may lead to OFCD syndrome according to the clinical feature of the fetus. In this case, male lethality had not occurred by the end of the second trimester, then termination of the pregnancy was conducted at a gestational age of 26 weeks. Sanger sequencing of parental samples revealed that the variant was maternally transmitted, which was consistent with the OFCD syndrome phenotypic features observed in her. Conclusions: In the study, we first present the affected male with a novel variant in BCOR that leads to the OFCD syndrome. Additionally, our study broadened the spectrum of BCOR results in the OFCD syndrome and provided the valuable references for prenatal genetic consultation. [ABSTRACT FROM AUTHOR]