Project description:In order to validate of CNV detection from low-coverage whole-genome sequencing in the blood samples from recurrent miscarriage couples, we employed a customized array Comparative Genomics Hybridization (aCGH, Agilent) approach as chromosomal microarray analysis (CMA) in present study for a cohort of 78 DNA samples from blood. CMA results were compared with low-coverage whole-genome sequencing detection results. 100% consistency was obtained in pathogenic or likely pathogenic CNVs detection.
Project description:In principle, whole-genome sequencing (WGS) of the human genome even at low coverage offers higher resolution for genomic copy number variation (CNV) detection compared to array-based technologies, which is currently the first-tier approach in clinical cytogenetics. There are, however, obstacles in replacing array-based CNV detection with that of low-coverage WGS such as cost, turnaround time, and lack of systematic performance comparisons. With technological advances in WGS in terms of library preparation, instrument platforms, and data analysis algorithms, obstacles imposed by cost and turnaround time are fading. However, a systematic performance comparison between array and low-coverage WGS-based CNV detection has yet to be performed. Here, we compared the CNV detection capabilities between WGS (short-insert, 3kb-, and 5kb-mate-pair libraries) at 1X, 3X, and 5X coverages and standardly used high-resolution arrays in the genome of 1000-Genomes-Project CEU genome NA12878. CNV detection was performed using standard analysis methods, and the results were then compared to a list of Gold Standard NA12878 CNVs distilled from the 1000-Genomes Project. Overall, low-coverage WGS is able to detect drastically more (approximately 5 fold more on average) Gold Standard CNVs compared to arrays and is accompanied with fewer CNV calls without secondary validation. Furthermore, we also show that WGS (at ≥1X coverage) is able to detect all seven validated deletions larger than 100 kb in the NA12878 genome whereas only one of such deletions is detected in most arrays. Finally, we show that the much larger 15 Mbp Cri-du-chat deletion can be clearly seen at even 1X coverage from short-insert WGS.
Project description:Recurrent miscarriage (RM) is the occurrence of repeated pregnancies that end in miscarriage of the fetus before 20 weeks of gestation. Recurrent miscarriages affect about 1-2% of couples trying to conceive; however, mechanisms leading to this complication are largely unknown. Our previous studies using comparative proteomics identified 314 differentially expressed proteins (DEPs) in placental villous. In this study, we identified 5479 proteins from a total of 34157 peptides in decidua of patients with early recurrent miscarriage. Further analysis identified 311 DEPs in the decidua tissue; 159 proteins showed the increased expression while 152 proteins showed decreased expression. These 311 proteins were further analyzed using Ingenuity Pathway Analysis (IPA). The results suggested that 50 DEPs could play important roles in the embryonic development. Furthermore, network analysis of the placental villous and decidua embryonic development DEPs was performed in STRING database to find the core gene. This study identifies several proteins that are specifically associated with embryonic development in decidua of patients with early recurrent miscarriage, these results provide new insights into potential biological mechanisms and may ultimately inform recurrent miscarriage.
Project description:In order to evaluate the performance of CNV detection in next-generation sequencing platform in varied sample types, we employed chromosomal microarray analysis (CMA) for validation of the samples with NGS-based detection results (NCBI Sequence Read Archive with accession number SRA296708). Besides array Comparative Genomics Hybridization (aCGH, Agilent) , we used a commerical SNP-array (Illumina) including early abortus, induced termination, prenatal samples and postnatal samples. CMA results were compared with NGS-based detection results. 100% consistency was obtained between NGS-based approach and CMA in pathogenic or likely pathogenic CNVs detection.
Project description:In order to evaluate the performance of CNV detection in next-generation sequencing platform in varied sample types, we employed chromosomal microarray analysis (CMA) for validation of the samples with NGS-based detection results (NCBI Sequence Read Archive with accession number SRA296708). Besides snp-array, we used a customized array Comparative Genomics Hybridization (aCGH, Agilent) approach for a cohort of clinical samples including early abortus, induced termination, prenatal samples and postnatal samples. CMA results were compared with NGS-based detection results. 100% consistency was obtained between NGS-based approach and CMA in pathogenic or likely pathogenic CNVs detection.
Project description:Chromosomal copy number variations (CNV) have been associated with various neurological and developmental disorders and chromosomal microarray (CMA) is a method of choice to diagnose Copy Number Gain/Loss syndromes. Recently, next-generation sequencing (NGS)-based low-coverage whole genome sequencing (LC-WGS) has been applied to detect Copy Number Gain/Loss syndromes. This dataset is intended to be used as a “Golden standard data set” for development of LC-WGS analysis method. It consists of patients (n=63) who have a mental delay and/or physical disability phenotype and normal (n=20) phenotype.
Project description:Ovarian cancer is a global problem, is typically diagnosed at a late stage and has no effective screening strategy. Platinum-based chemotherapy or Poly(ADP-ribose) polymerase inhibitors (PARPis) treatment are most frequently applied for ovarian cancer patients who are inoperable and in the advanced stage. The recognition of homologous recombination deficiency (HRD) as a biomarker to predict the effect of Platinum-based or PARPis treatment. WGS and WES can detect tumor HRD status but have several disadvantages which restrict their clinical application. My choice HRD CDx and Foundation Focus CDx are approved by FDA for HRD detection, however, whether they are applicable to the Chinese population or not is unknown. In this study, we created an SNP-based Tg-NGS panel to fill in gaps in Chinese patients’ HRD screening. Our results showed that the panel is cost and time-saving compared with WGS, but equivalent with SNP microarray on CNV and HRD detection. In summary, this newly developed kit is promising in clinical application to guide ovarian cancer and even other cancer types therapy.
Project description:Miscarriage occurs in 15-20% of clinical pregnancies. While chromosomal errors are observed in over 50%, causes of karyotypically normal losses are poorly understood. DNA methylation undergoes reprogramming during development and must be appropriately set to maintain a healthy pregnancy. We hypothesize that aberrant DNA methylation may cause karyotypically normal miscarriage, particularly among women experiencing recurrent miscarriage (RM). DNA methylation in first trimester chorionic villi was assessed in chromosomally normal miscarriages from women with RM (N=33) or isolated miscarriage (M, N=21), and elective terminations (TA, N=16). Differentially methylated candidate loci were identified using the Illumina Infinium HumanMethylation27 BeadChip array by comparing 10 RM to 10 TA samples. Follow up showed a significant increase in methylation in RM and M compared to TA placentae at the CYP1A2 (p=0.002) and AXL (p=0.02) promoters and decrease at the DEFB1 (p=0.008) promoter. Gene function analysis showed an enrichment of imprinted genes (p=9.53E-10) and genes previously associated with RM (p=9.51E-06). DNA methylation was evaluated at 7 imprinted loci using bisulfite pyrosequencing. An increase of outliers at these loci was observed in RM (3.9%) compared to M (0%) and TA (0.9%) (p=0.02), with increased average methylation at the H19/IGF2 ICR1 in M samples (p<0.0001). Altered DNA methylation in the placenta at specific loci, as well as global dysregulation in specific cases, may contribute to or be a consequence of placental insufficiency in karyotypically normal miscarriage. First-trimester placental villi samples from karyotypically normal miscarriages from recurrent miscarriage patients (N, N=10) and chromosomally normal elective terminations (PZET, N=10).
Project description:This study was designed to investigate the miRNA expression profilein human chorionic villi from early recurrent miscarriage. We identified 155 miRNAs exhibiting over 2-fold change in expression levels (P<0.05) by microarray,