Application of Chromosomal Microarray Analysis in Genetic Reasons of Miscarriage Tissues.

Background: The potential causes of miscarriage are very complex, including genetic, immune, infectious, and endocrine factors. 50%-60% of miscarriages are caused by chromosomal abnormalities. Chromosomal microarray analysis (CMA) is a key tool in this context, capable of detecting not only copy number variations (CNV) but also loss of heterozygosity (LOH). CMA has been used as a tool to investigate the genetic reasons for miscarriage. Methods: In our study, chromosomal microarray analysis (CMA) conducted 1220 miscarriage villous tissues. The results from this technology were used to identify the genetic reasons for miscarriage and evaluated strategies for subsequent pre-pregnancy planning. Results: Here, the abnormality rate of miscarriage was 56.07%(684/1220). The aneuploidy rate accounted for 81.14%(555/684), and was significantly higher in group >35-year-old age. The second most common genetic reason for miscarriage was polyploidy, accounting for 10.09%(69/684). Additionally, we discovered loss of heterozygosity (LOH) in a small percentage of cases, accounting for 2.20%(15/684) reason for miscarriage genetic reasons, due to the advantage of CMA can detect isodisomy (a kind of uniparental disomy). 45 cases (6.58%) with copy number variants, which due to the CMA can detect copy number variations. Conclusion: Our study indicated that miscarriage villous tissues should be performed genetic analysis, seek help from professional genetic counseling.

GR/P300 Regulates MKP1 Signaling Pathway and Mediates Depression-like Behavior in Prenatally Stressed Offspring.

Accumulating evidence suggests that prenatal stress (PNS) increases offspring susceptibility to depression, but the underlying mechanisms remain unclear. We constructed a mouse model of prenatal stress by spatially restraining pregnant mice from 09:00-11:00 daily on Days 5-20 of gestation. In this study, western blot analysis, quantitative real-time PCR (qRT‒PCR), immunofluorescence, immunoprecipitation, chromatin immunoprecipitation (ChIP), and mifepristone rescue assays were used to investigate alterations in the GR/P300-MKP1 and downstream ERK/CREB/TRKB pathways in the brains of prenatally stressed offspring to determine the pathogenesis of the reduced neurogenesis and depression-like behaviors in offspring induced by PNS. We found that prenatal stress leads to reduced hippocampal neurogenesis and depression-like behavior in offspring. Prenatal stress causes high levels of glucocorticoids to enter the fetus and activate the hypothalamic‒pituitary‒adrenal (HPA) axis, resulting in decreased hippocampal glucocorticoid receptor (GR) levels in offspring. Furthermore, the nuclear translocation of GR and P300 (an acetylation modifying enzyme) complex in the hippocampus of PNS offspring increased significantly. This GR/P300 complex upregulates MKP1, which is a negative regulator of the ERK/CREB/TRKB signaling pathway associated with depression. Interestingly, treatment with a GR antagonist (mifepristone, RU486) increased hippocampal GR levels and decreased MKP1 expression, thereby ameliorating abnormal neurogenesis and depression-like behavior in PNS offspring. In conclusion, our study suggested that the regulation of the MKP1 signaling pathway by GR/P300 is involved in depression-like behavior in prenatal stress-exposed offspring and provides new insights and ideas for the fetal hypothesis of mental health.

YTHDF3 modulates the Cbln1 level by recruiting BTG2 and is implicated in the impaired cognition of prenatal hypoxia offspring.

The "Fetal Origins of Adult Disease (FOAD)" hypothesis holds that adverse factors during pregnancy can increase the risk of chronic diseases in offspring. Here, we investigated the effects of prenatal hypoxia (PH) on brain structure and function in adult offspring and explored the role of the N6-methyladenosine (m6A) pathway. The results suggest that abnormal cognition in PH offspring may be related to the dysregulation of the m6A pathway, specifically increased levels of YTHDF3 in the hippocampus. YTHDF3 interacts with BTG2 and is involved in the decay of Cbln1 mRNA, leading to the down-regulation of Cbln1 expression. Deficiency of Cbln1 may contribute to abnormal synaptic function, which in turn causes cognitive impairment in PH offspring. This study provides a scientific clues for understanding the mechanisms of impaired cognition in PH offspring and provides a theoretical basis for the treatment of cognitive impairment in offspring exposed to PH.

Slow flow HD and traditional CDFI technologies in identifying pulmonary veins in the first trimester.

OBJECTIVE: This study aims to assess the feasibility and effectiveness of color doppler flow imaging (CDFI) technology and the Slow Flow HD imaging technique in identifying fetal pulmonary veins (PVs) in the first trimester (11-13 + 6 weeks), and further explore the factors affecting fetal pulmonary vein identification in early pregnancy. METHODS: Echocardiography and scanning of PVs were performed in 240 normal singleton fetuses in early pregnancy by using CDFI and slow flow HD techniques, to compare the ability of two methods to identify the PVs. Slow Flow HD technology was used to further investigate the difference of PVs identification at different gestational ages [group I (11-11 + 6 weeks), group II (12-12 + 6 weeks), group III (13-13 + 6 weeks)] and with different maternal body mass indices (BMI) (≥ 25 and < 25). In 31 cases of 240 fetuses, transvaginal ultrasonography was added due to maternal habitus or significant retroversion of the uterus, and the difference in PVs identification between transabdominal and transvaginal examination was analyzed. RESULTS: Successful PVs identification rates via CDFI and Slow Flow HD were 32.0% and 88.3%, respectively (p < 0.05). The identification rate of at least one and two pulmonary veins in Slow Flow HD was 88.3% and 76.2%, and all four pulmonary veins in 11.6% (p < 0.05). The identification rate of group I, II and III were 76.4%, 88.9% and 96.0%, respectively. The identification rate was 45.1% in the transabdominal ultrasound group and 83.8% in the transvaginal ultrasound group. The identification rate was 62.5% in the BMI ≥ 25 group and 94.7% in the BMI < 25 group (p < 0.05). CONCLUSIONS: Slow Flow HD can detect PVs in early pregnancy more often than using CDFI. Slow Flow HD is a feasible and effective imaging technique for evaluating PVs in early pregnancy.

Sleep Quality is Associated with Axial Length Elongation in Myopic Children Receiving Orthokeratology: A Retrospective Study.

Purpose: To identify potential demographic and lifestyle factors associated with progression of myopia with orthokeratology (ortho-k) treatment via follow-up of axial length (AL). Methods: In this retrospective observational study, demographics, ocular parameters, near-work distance, outdoor activities, and sleep quality were analyzed in 134 children with myopia aged 8~15 years using ortho-k and a follow-up for one year. Results: Compared with the slow progression group, the participants in the fast progression group were younger in age (10.55 ±1.70 years vs 9.90 ±1.18 years, P = 0.009), demonstrated higher spherical equivalent (SE) value (-2.52 ±0.63 diopters (D) vs -3.05 ±0.89 D, P < 0.001), shorter near-work distance (P = 0.010), and poorer sleep quality (Pittsburgh sleep quality index [PSQI], 4.79 ±1.29 vs 3.81 ±1.38, P < 0.001) in the one-year follow-up. Furthermore, multivariate linear regression analyses showed that baseline age (B =-0.020, P = 0.020), SE (B = 0.0517, P < 0.001), and total PSQI (B=0.026, P = 0.001) were associated with axial elongation. Advanced logistic regression analyses demonstrated that shorter average near-work distance (P = 0.034), higher SE value (P = 0.023), and poorer sleep quality (P = 0.003) were associated with fast axial elongation. Conclusion: Sleep quality is one of the key factors associated with axial elongation in children with myopia after using ortho-k for one year. Further studies are required to confirm this observation and expand its practical applications.

[Analysis of a fetus with multiple malformations due to a hemizygous variant of FANCB gene].

OBJECTIVE: To explore the genetic basis for a fetus with limb abnormality and cardiac malformation. METHODS: Clinical data of a fetus diagnosed at the Shandong Provincial Maternal and Child Health Care Hospital on April 30th, 2021 was collected. Whole exome sequencing (WES) was carried out, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. X-inactivation analysis was carried out for the female members of its family. RESULTS: The fetus was found to have meningoencephalocele, absence of bilateral radii, cleft lip, abnormal great arteries, and single umbilical artery at the gestational age of 11+ weeks. Sequencing revealed that the fetus has harbored a hemizygous c.1162del (p.Y388Tfs*7) variant of the FANCB gene, which was maternally inherited. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and ClinGen, the variant was classified as pathogenic (PVS1+PM2_Supporting+PP4). X-inactivation analysis has revealed complete skewed X-inactivation in the pregnant woman and her mother. CONCLUSION: The hemizygous c.1162del (p.Y388Tfs*7) variant of the FANCB gene probably underlay the multiple malformations in this fetus.

Detection of complex chromosome rearrangements using optical genome mapping.

Chromosomal structural variations (SVs) are a main cause of human genetic disease. Currently, karyotype, chromosomal microarray analysis (CMA), and fluorescent in situ hybridization (FISH) form the backbone of current routine diagnostics (CRD). These methods have their own limitations. CRD cannot identify cryptic balanced SVs and complex SVs even if these techniques were performed either simultaneously or in a sequential manner. Optical genome mapping (OGM) is a novel technology that can identify several classes of SVs with higher resolution, but studies on the applicability of OGM and its comparison with CRD are inadequate for difficult and complicated chromosomal SVs are lacking. Herein, seven patients with definite complicated SVs involving at least two breakpoints (BPs) were recruited for this study. The results of BPs and SVs from OGM were compared with those from CRD. The results showed that all BPs of five samples and partial BPs of two samples were detected by OGM. The undetected BPs were all close to the repeat-rich gap region. Besides, OGM also detected additional SVs including a cryptic balanced translocation, two additional complex chromosomal rearrangement (CCR). OGM yielded the additional information, such as the orientation of acentric fragments, BP positions, and genes mapped in the BP region for all the cases. The accuracy of additional SVs and BPs detected by OGM was verified by FISH panel and next-generation sequencing and Sanger sequencing. Taken together, OGM exhibit a better performance in detecting chromosomal SVs compared to the CRD. We suggested that OGM method should be utilized in the clinical examination to improve the efficiency and accuracy of genetic disease diagnosis, supplemented by FISH or karyotyping to compensate for the SVs in the repeat-rich gap region if necessary.

Development of CRISPR Cas9, spin-off technologies and their application in model construction and potential therapeutic methods of Parkinson's disease.

Parkinson's disease (PD) is one of the most common degenerative diseases. It is most typically characterized by neuronal death following the accumulation of Lewis inclusions in dopaminergic neurons in the substantia nigra region, with clinical symptoms such as motor retardation, autonomic dysfunction, and dystonia spasms. The exact molecular mechanism of its pathogenesis has not been revealed up to now. And there is a lack of effective treatments for PD, which places a burden on patients, families, and society. CRISPR Cas9 is a powerful technology to modify target genomic sequence with rapid development. More and more scientists utilized this technique to perform research associated neurodegenerative disease including PD. However, the complexity involved makes it urgent to organize and summarize the existing findings to facilitate a clearer understanding. In this review, we described the development of CRISPR Cas9 technology and the latest spin-off gene editing systems. Then we focused on the application of CRISPR Cas9 technology in PD research, summarizing the construction of the novel PD-related medical models including cellular models, small animal models, large mammal models. We also discussed new directions and target molecules related to the use of CRISPR Cas9 for PD treatment from the above models. Finally, we proposed the view about the directions for the development and optimization of the CRISPR Cas9 technology system, and its application to PD and gene therapy in the future. All these results provided a valuable reference and enhanced in understanding for studying PD.

CRISPR/Cas9: implication for modeling and therapy of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a deadly neurological disease with a complicated and variable pathophysiology yet to be fully understood. There is currently no effective treatment available to either slow or terminate it. However, recent advances in ALS genomics have linked genes to phenotypes, encouraging the creation of novel therapeutic approaches and giving researchers more tools to create efficient animal models. Genetically engineered rodent models replicating ALS disease pathology have a high predictive value for translational research. This review addresses the history of the evolution of gene editing tools, the most recent ALS disease models, and the application of CRISPR/Cas9 against ALS disease.

Comprehensive Analysis of Hemophilia A (CAHEA): Towards Full Characterization of the F8 Gene Variants by Long-Read Sequencing.

BACKGROUND: Hemophilia A (HA) is the most frequently occurring X-linked bleeding disorder caused by heterogeneous variants in the F8 gene, one of the largest genes known. Conventional molecular analysis of F8 requires a combination of assays, usually including long-range polymerase chain reaction (LR-PCR) or inverse-PCR for inversions, Sanger sequencing or next-generation sequencing for single-nucleotide variants (SNVs) and indels, and multiplex ligation-dependent probe amplification for large deletions or duplications. MATERIALS AND METHODS: This study aimed to develop a LR-PCR and long-read sequencing-based assay termed comprehensive analysis of hemophilia A (CAHEA) for full characterization of F8 variants. The performance of CAHEA was evaluated in 272 samples from 131 HA pedigrees with a wide spectrum of F8 variants by comparing to conventional molecular assays. RESULTS: CAHEA identified F8 variants in all the 131 pedigrees, including 35 intron 22-related gene rearrangements, 3 intron 1 inversion (Inv1), 85 SNVs and indels, 1 large insertion, and 7 large deletions. The accuracy of CAHEA was also confirmed in another set of 14 HA pedigrees. Compared with the conventional methods combined altogether, CAHEA assay demonstrated 100% sensitivity and specificity for identifying various types of F8 variants and had the advantages of directly determining the break regions/points of large inversions, insertions, and deletions, which enabled analyzing the mechanisms of recombination at the junction sites and pathogenicity of the variants. CONCLUSION: CAHEA represents a comprehensive assay toward full characterization of F8 variants including intron 22 and intron 1 inversions, SNVs/indels, and large insertions and deletions, greatly improving the genetic screening and diagnosis for HA.

Genetic analysis and prenatal diagnosis of short-rib thoracic dysplasia 3 with or without polydactyly caused by compound heterozygous variants of DYNC2H1 gene in four Chinese families.

Background: To describe the genetic variation of dynein cytoplasmic 2 heavy chain 1 (DYNC2H1) gene in four Chinese families affected with short-rib thoracic dysplasia 3 with or without polydactyly (SRTD3), and to provide evidence for accurate prenatal diagnosis and genetic counseling. Methods: The detailed clinical prenatal sonographic features of four fetuses with SRTD3 were carried out. Trio-whole exome sequencing (WES) and proband-WES sequencing was applied to filtrated causative variants in four families. The causative variants of each family were validated in by Sanger sequencing. Bioinformation analysis was applied to predict the harmfulness of these mutations and perform the protein-protein interaction network and Gene Ontology (GO) analysis. A vitro minigene splicing assay was conducted to assess the influence of the splice site variant. Results: Typical characterization of the four fetuses included short long bones, short ribs, narrow chest, hand and foot posture abnormalities, femur short in diameter and slightly bowing, cardiac abnormalities, and so on. Moreover, eight compound heterozygous variants of DYNC2H1 (NM_001080463.2): c.3842A>C (p.Tyr1281Ser) and c.8833-1G>A, c.8617A>G (p.Met2873Val) and c.7053_7054del (p.Cys2351Ter), c.5984C>T (p.Ala1995Val) and c.10219C>T (p.Arg3407Ter), c.5256del (p.Ala1753GlnfsTer13) and c.9737C>T (p.Thr3246Ile), were identified. Among which, c.10219C>T (p.Arg3407Terp), c.5984C>T (p.Ala1995Val) and c.9737C>T (p.Thr3246Ile) were reported in ClinVar databases, and c.8617A>G (p.Met2873Val), c.10219C>T (p.Arg3407Ter), c.5984C>T (p.Ala1995Val) were found in HGMD databases. Four variants (c.3842A>C (p.Tyr1281Ser), c.8833-1G>A, c.7053_7054del (p.Cys2351Ter) and c.5256del (p.Ala1753GlnfsTer13) were first reported as novel mutations. According to the ACMG guidelines, c.8617A>G (p.Met2873Val), c.7053_7054del (p.Cys2351Ter), c.5984C>T (p.Ala1995Val), c.10219C>T (p.Arg3407Ter) and c.5256del (p.Ala1753GlnfsTer13) were rated as pathogenic or likely pathogenic variants, others variants were predicted to be variants of uncertain significance mutations. The minigene assay results indicated that c.8833-1G>A caused the skipping over exon 56, resulting in exon 56 loss. Conclusion: In our study, we analyzed the genetic mutations in four fetuses with SRTD3 by whole exome sequencing and identified pathogenic variants causing SRTD3. Our results expand the mutation spectrum of DYNC2H1 in SRTD3, which is helpful for the accurate prenatal diagnosis of SRTD3 fetuses and provide useful strategies for genetic counseling.

HDAC3 Inhibition Alleviates High-Glucose-Induced Retinal Ganglion Cell Death through Inhibiting Inflammasome Activation.

Purpose: The exact effects of histone deacetylase 3 (HDAC3) inhibition in DR related retinal ganglion cells (RGCs) death remained unclear. This study is aimed at detecting the influence of HDAC3 on the high-glucose-induced retinal ganglion cell death. Methods: The retinal HDAC3 expression in DR of different time points was analyzed by immunohistochemical assay and western blot. Besides, the expression of HDAC3 and both retinal thickness and RGC loss were analyzed. The effects of HDAC3 inhibitor on cell viability, oxidative stress, and apoptosis in high-glucose- (HG-) treated RGCs were analyzed. Both inflammatory and antioxidative factors were detected by ELISA. Results: Advanced effects of HDAC3 inhibition on the expression of NLRP3 inflammasome were detected using western blots. High HDAC3 expression was detected only in the late DR mice (4 months of diabetes duration) but not early DR mice (2 months of diabetes duration). The immunohistochemical assay showed that HDAC3 expression was correlated with both retinal thickness and RCG contents. HDAC3 inhibitor significantly protected the HG-treated RGCs from damaged cell viability, severe apoptosis, and oxidative stress. Advanced pathway analyses showed that HDAC3 inhibition inactivated NLRP3 inflammasome and thus alleviated retinal inflammation. Conclusion. In conclusion, HDAC3 was involved in RGC loss and thus promoted the progression of neurodegeneration of DR. Besides, HDAC3 inhibitor demonstrated protective effects in neurodegeneration in DR through downregulation of NLRP3 activity. The effects of HDAC3 inhibitor in DR management should be confirmed in clinical trials.

Kaempferol ameliorates the regulatory effects of PVT1/miR-214 on epithelial-mesenchymal transition through the PAK4/ß-catenin axis in SRA01/04 cells.

Aim: To investigate whether kaempferol exhibits a protective effect on high glucose-induced epithelial-mesenchymal transition (EMT) by mediating the PVT1/miR-214 and PAK4/ß-catenin pathways in SRA01/04 cells. Methods & methods: qRT-PCR and western blot assays were used for gene and protein determination, and migration and invasion assays were conducted. A coimmunoprecipitation assay was used for determining protein interactions. Results: High glucose effectively upregulated PVT1 expression, downregulated miR-214 expression and promoted cell migration and invasion. Kaempferol attenuated high glucose-induced EMT by increasing PVT1 expression and decreasing miR-214 expression. PAK4 was identified as a direct target of miR-214. PAK4 overexpression could rescue the effects of PVT1 deficiency on SRA01/04 cells. Conclusion: Kaempferol ameliorated the regulatory effects of PVT1/miR-214 on high glucose-induced EMT through PAK4/ß-catenin in SRA01/04 cells.

[Application of high-throughput sequencing technology for the detection of fetal copy number variations].

OBJECTIVE: To assess the value of non-invasive prenatal testing (NIPT) for the detection of fetal copy number variations (CNVs) in addition to trisomies 21, 18, and 13. METHODS: A total of 37 306 pregnant women underwent the NIPT test. For those with fetal CNVs indicated by NIPT and accepted invasive prenatal diagnosis, amniotic fluid samples were obtained for chromosomal karyotyping analysis and chromosome microarray analysis (CMA). All cases were followed up. RESULTS: Among the 37 306 cases, 78 (0.209%) were predicted to have fetal CNVs. Among these, 52 pregnant women accepted invasive prenatal diagnosis, and 15 of them (28.85%) obtained a consistent result. Follow up of 26 women who refused invasive prenatal diagnosis have found 2 cases with spontaneous abortion, 2 with induced labor for fetal malformation indicated by ultrasonography, and 1 had multiple malformations and a consistent result by CMA, which yielded an abnormal rate of 19.23%. CONCLUSION: NIPT can signal fetal chromosomal abnormalities through detection of gain and/or loss of fetal DNA copies. Combined chromosomal karyotyping and CMA can increase the detection rate for common chromosomal aneuploidies and CNVs, thereby provide a basis for genetic counseling for the affected families.

[Application of chromosomal microarray analysis and next-generation sequencing for the analysis of abortic tissues].

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) and next-generation sequencing (NGS) for the analysis of abortic tissues. METHODS: A total of 242 samples of spontaneous abortion were collected and tested by CMA or NGS. RESULTS: The detection was successfully in 238 cases (98.35%). In total 143 cases of chromosomal abnormalities were detected, which accounted for 60.08% of all cases. Numerical chromosomal abnormalities were found in 133 cases(93.01%), structural abnormalities were found in 9 cases (6.29%), and uniparental disomy was found in 1 case(0.70%). CONCLUSION: Both CMA and NGS have the advantages of high-throughput, good coverage, high resolution and rapid analysis. They can be used for the detection of the causes of spontaneous abortions. CMA is more useful for the detection of aneuploidies and uniparental disomy, while NGS has advantages in its throughput, capacity in detecting low percentage chimerism and cost, which can provide more options for clinicians.

Lidocaine inhibits the progression of retinoblastoma in vitro and in vivo by modulating the miR­520a­3p/EGFR axis.

Retinoblastoma (RB) is a common malignant tumor in children. Lidocaine is a local anesthetic and anti­arrhythmic drug, and has been reported to possess anti­tumor properties. MicroRNAs (miRs) are a group of endogenous small noncoding RNAs that have important roles in various biological processes via actions on target genes. The aim of the present study was to investigate the effect of lidocaine on retinoblastoma in vitro and in vivo. CCK­8 assay and flow cytometry assay were used to measure cell viability and apoptosis. The relationship between miR­520a­3p and EGFR was predicted and confirmed by TargetScan and dual­luciferase reporter assay. For in vivo study, tumor xenograft was performed. In addition, gene and protein expression was detected using reverse transcription­quantitative polymerase chain reaction and western blotting respectively. In the present study, it was observed that lidocaine inhibited the proliferation and induced the apoptosis of RB cells. miR­520a­3p was reported to be downregulated in RB tissues and cell lines; treatment with lidocaine increased the expression of miR­520a­3p in RB cells. The human epidermal growth factor receptor (EGFR) was identified as a direct target of miR­520a­3p, and its expression was negatively associated with that of miR­520a­3p. Additionally, EGFR was upregulated in RB tissues and cell lines; treatment with lidocaine decreased the expression of EGFR in RB cells. Furthermore, compared with treatment with lidocaine alone, the combination of transfection with miR­520a­3p inhibitor and lidocaine treatment significantly decreased the expression of miR­520a­3p, increased EGFR expression, promoted RB cell proliferation and reduced the apoptosis of cells in vitro, and increased tumor volume and weight in vivo. The results indicated that lidocaine reduced the proliferation and induced the apoptosis of RB cells by decreasing EGFR expression via the upregulation of miR­520a­3p, suggesting that the miR­520a­3p/EGFR axis may be a novel therapeutic target in the treatment of RB.

[False positive non-invasive prenatal testing results due to vanishing twins].

OBJECTIVE: To explore the mechanism and duration of false positive results of non-invasive prenatal testing (NIPT) caused by vanishing twins. METHODS: To detect the variation of cell-free fetal DNA fraction before and after the fetal death and explore its influence on the results of NIPT at different gestational weeks. Prenatal diagnosis was also carried out on amniotic fluid sample derived from the survivor twin. After birth, the two placentas and papyraceous fetus were obtained to ascertain the definitive genetic diagnosis and pathological changes through fluorescence in situ hybridization, fluorescence quantitative PCR and histopathological examination. Eight cases of vanishing twins leading to discordant NIPT results were reviewed for determining the duration of this influence. RESULTS: The vanishing twin has led to immediate flooding of cfDNA into the maternal plasma due to necrotic cytotrophoblasts, which in turn caused increased release of fetal DNA in a short time. However, this did not change the NIPT result for a period of time. The tissue and chorionic villi of perished fetus presented extensive degenerative necrosis. CONCLUSION: The false positive NIPT result caused by vanishing twins may be attributed to continuous release of DNA fragments into the maternal plasma by the fetuses. The influence of the vanished fetuses, which may lead to discordant NIPT results, can last for at least 7-8 weeks but no more than 12-14 weeks during the first and second trimester.

Noninvasive prenatal testing for fetal subchromosomal copy number variations and chromosomal aneuploidy by low-pass whole-genome sequencing.

BACKGROUND: Expanding noninvasive prenatal testing (NIPT) to include the detection of fetal subchromosomal copy number variations (CNVs) significantly decreased the sensitivity and specificity. Developing analytic pipeline to achieve high performance in the noninvasive detection of CNVs will largely contribute to the application of CNVs screening in clinical practice. METHODS: We developed the Noninvasively Prenatal Subchromosomal Copy number variation Detection (NIPSCCD) method based on low-pass whole-genome sequencing, and evaluated its efficacy in detecting fetal CNVs and chromosomal aneuploidies with 20,003 pregnant women. RESULTS: Totally, NIPSCCD identified 36 CNVs, including 29 CNVs consistent and 7 CNVs inconsistent with amniocytes tests. Additionally, seven fetal CNVs identified by amniocytes testing were undetected by NIPSCCD. The sensitivities for detecting CNVs > 10 Mb, 5 Mb-10 Mb, and CNVs < 5 Mb were 91.67%, 100.00%, and 68.42%, respectively. Moreover, NIPSCCD identified 103/ true positive trisomy 21/18/13 cases and 21 false positives, producing an overall 100.00% sensitivity and 99.89% specificity. CONCLUSION: NIPSCCD showed a good performance in detecting fetal subchromosomal CNVs, especially for CNVs >10 Mb, and can be incorporated into the routine NIPT chromosomal aneuploidies screening with high sensitivity and specificity.

Novel chromosomal microduplications associated with dolichocephaly craniosynostosis: A case report.

INSTRUCTION: Craniosynostosis is a human disorder characterized by the premature fusing of the cranial sutures in infants. Point mutations in hotspot genes such as FGFRs are the well-recognized causes of syndromic craniosynostosis, but chromosomal abbreviations may also play an important role in developing this disease. Here, we report the case in China of a 2-year-boy dolichocephaly craniosynostosis. Karyotyping by both G-bind staining and array-based DNA hybridization identified microduplications on Chromosomes 8p11.22 q12.1 and 16q11.2 q21, but none of the known pathogenic mutations was detected. CONCLUSIONS: This finding not only expands knowledge on the genetic mechanism of craniosynostosis but also provides a new target for the early diagnosis of this rare disease.

A maternally inherited 8.05 Mb Xq21 deletion associated with Choroideremia, deafness, and mental retardation syndrome in a male patient.

BACKGROUND: Deletions in Xq21 cause various congenital defects in males including choroideremia, deafness and mental retardation, depending on their size and gene content. Until now only a limited number of patients with Xq21 deletions has been reported. CASE PRESENTATION: Here we describe a 17-year-old male with choroideremia, deafness, and mental retardation syndrome. Using SNP arrays, an 8.05 Mb deletion in Xq21 was identified inherited from the apparently healthy mother. The deleted region harbors 12 OMIM genes, of which POU3F4, CHM, and ZNF711 might have contributed to the patient's phenotype including hearing loss, poor vision, and intellectual disability. Moreover, the patient's mother exhibits a normal phenotype while carrying the same deletion, which is often observed in previous studies on female carriers in families with this syndrome. CONCLUSIONS: Our study confirms the causative effect between the Xq21 deletion in males and choroideremia, deafness and mental retardation.