RESUMO
Next-generation sequencing is emerging as a reliable and accurate technology for pre-implantation genetic diagnosis (PGD) of aneuploidies and translocations. The aim of this study was to extend the clinical utility of copy number variation sequencing (CNV-Seq) to the detection of small pathogenic copy number variations (CNVs) associated with chromosome disease syndromes. In preliminary validation studies, CNV-Seq was highly sensitive and specific for detecting small CNV in whole-genome amplification products from three replicates of one and five cell samples, with a resolution in the order of 1-2 Mb. Importantly, the chromosome positions of all CNV were correctly mapped with copy numbers similar to those measured in matching genomic DNA samples. In seven clinical PGD cycles where results were obtained for 34 of 35 blastocysts, CNV-Seq identified 18 blastocysts with aneuploidies, one with an aneuploidy and a 4.98 Mb 5q35.2-qter deletion associated with Sotos syndrome, one with a 6.66 Mb 7p22.1-pter deletion associated with 7p terminal deletion syndrome and 14 with no detectable abnormalities that were suitable for transfer. On the basis of these findings, CNV-Seq displays the hallmarks of a comprehensive PGD technology for detection of aneuploidies and CNVs that are known to affect the development and health of patient's embryos.
Assuntos
Transtornos Cromossômicos/diagnóstico , Embrião de Mamíferos/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Diagnóstico Pré-Implantação/métodos , Aneuploidia , Variações do Número de Cópias de DNA , Genoma Humano , Humanos , Sensibilidade e EspecificidadeRESUMO
Chromosome aneuploidies commonly arise in embryos produced by assisted reproductive technologies and represent a major cause of implantation failure and miscarriage. Currently, preimplantation genetic diagnosis (PGD) is performed by array-based methods to identify euploid embryos for transfer to the patient. We speculated that a combination of next-generation sequencing technologies and sophisticated bioinformatics would deliver a more comprehensive and accurate methodology to improve the overall efficacy of embryo testing. To meet this challenge, we developed a high-resolution copy number variation (CNV) sequencing pipeline suitable for single-cell analysis. In validation studies, we showed that CNV-Seq was highly sensitive and specific for detection of euploidy, aneuploidy, and segmental imbalances in 24 whole genome amplification samples from PGD embryos that were originally diagnosed by gold standard array comparative genomic hybridization. In addition, CNV-Seq was capable of detecting, mapping, and accurately quantifying terminal chromosome imbalances down to 1 Mb in size originating from abnormal segregation of translocation chromosomes. These validation studies indicate that CNV-Seq displays the hallmarks of an accurate and reliable embryo test with the potential to further improve the overall efficacy of PGD.
Assuntos
Aneuploidia , Blastocisto , Fertilização in vitro , Humanos , Reação em Cadeia da Polimerase , Diagnóstico Pré-Implantação/métodos , Reprodutibilidade dos TestesRESUMO
Embryos produced by assisted reproductive technologies are commonly associated with a high level of aneuploidy. Currently, 24-chromosome profiling of embryo biopsy samples by array-based methods is available to identify euploid embryos for transfer that have a higher potential for implantation and development to term. From a laboratory and patient perspective, there is a need to explore the feasibility of developing an alternative method for routine aneuploidy assessment of embryos that would be more comprehensive, cost-effective, and efficient. We speculated that aneuploidy could be readily assessed in test single-cell biopsy samples by first performing whole genome amplification followed by library generation, massively parallel shot-gun sequencing, and finally bioinformatics analysis to quantitatively compare the ratio of uniquely mapped reads to reference cells. Using Down syndrome as an example, the copy number change for chromosome 21 was consistently 1.5-fold higher in multiple cell and single-cell samples with a 47,XX,+21 karyotype. Applying the validated sequencing strategy to 10 sister blastomeres from a single human embryo, we showed that the aneuploidy status called by sequencing was consistent with short tandem repeat allelic profiling. These validation studies indicate that aneuploidy detection using sequencing-based methodology is feasible for further improving the practice of preimplantation genetic diagnosis.
Assuntos
Aneuploidia , Blastocisto/fisiologia , Síndrome de Down/diagnóstico , Síndrome de Down/embriologia , Diagnóstico Pré-Implantação/métodos , Intervalos de Confiança , DNA/química , DNA/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento de Nucleotídeos em Larga Escala/tendências , Humanos , Gravidez , Reprodutibilidade dos Testes , Técnicas de Reprodução AssistidaRESUMO
BACKGROUND: Aberrant DNA methylation is an early event during tumorigenesis. In the present study, we aimed to construct a methylation diagnostic tool using urine sediment for the detection of urothelial bladder carcinoma, and improved the diagnostic performance of the model by incorporating single-nucleotide polymorphism (SNP) sites. METHODS: A three-stage analysis was carried out to construct the model and evaluate the diagnostic performance. In stage I, two small cohorts from Xiangya hospital were recruited to validate and identify the detailed regions of collected methylation biomarkers. In stage II, proof-of-concept study cohorts from the Hunan multicenter were recruited to construct a diagnostic tool. In stage III, a blinded cohort comprising suspicious UBC patients was recruited from Beijing single center to further test the robustness of the model. RESULTS: In stage I, single NRN1 exhibited the highest AUC compared with six other biomarkers and the Random Forest model. At the best cutoff value of 5.16, a single NRN1 biomarker gave a diagnosis with a sensitivity of 0.93 and a specificity of 0.97. In stage II, the Random Forest algorithm was applied to construct a diagnostic tool, consisting of NRN1, TERT C228T and FGFR3 p.S249C. The tool exhibited AUC values of 0.953, 0.946 and 0.951 in training, test and all cohorts. At the best cutoff value, the model resulted in a sensitivity of 0.871 and a specificity of 0.947. In stage III, the diagnostic tool achieved a good discrimination in the external validation cohort, with an overall AUC of 0.935, sensitivity of 0.864 and specificity of 0.895. Additionally, the model exhibited a superior sensitivity and comparable specificity compared with conventional cytology and FISH. CONCLUSIONS: The diagnostic tool exhibited a highly specific and robust performance. It may be used as a replaceable approach for the detection of UBC.
RESUMO
BACKGROUND: To improve the selection of patients for ureteroscopy, avoid excessive testing and reduce costs, we aimed to develop and validate a diagnostic urine assay for upper tract urinary carcinoma (UTUC). METHODS: In this cohort study we recruited 402 patients from six Hunan hospitals who underwent ureteroscopy for hematuria, including 95 patients with UTUC and 307 patients with non-UTUC findings. Midstream morning urine samples were collected before ureteroscopy and surgery. DNA was extracted and qPCR was used to analyze mutations in TERT and FGFR3 and the methylation of NRN1. In the training set, the random forest algorithm was used to build an optimal panel. Lastly, the Beijing cohort (n = 76) was used to validate the panel. RESULTS: The panel combining the methylation with mutation markers led to an AUC of 0.958 (95% CI: 0.933-0.975) with a sensitivity of 91.58% and a specificity of 94.79%. The panel presented a favorable diagnostic value for UTUC vs. other malignant tumors (AUC = 0.920) and UTUC vs. benign disease (AUC = 0.975). Furthermore, combining the panel with age revealed satisfactory results, with 93.68% sensitivity, 94.44% specificity, AUC = 0.970 and NPV = 98.6%. In the external validation process, the model showed an AUC of 0.971, a sensitivity of 95.83% and a specificity of 92.31, respectively. CONCLUSIONS: A novel diagnostic model for analyzing hematuria patients for the risk of UTUC was developed, which could lead to a reduction in the need for invasive examinations. Combining NRN1 methylation and gene mutation (FGFR3 and TERT) with age resulted in a validated accurate prediction model.
RESUMO
BACKGROUND: The clinical diagnostic method for bladder cancer is cystoscopy, an invasive, expensive and inconvenient clinical test. Using urinary cell-free DNA (cfDNA) to develop non-invasive test for bladder cancer was a promising liquid biopsy. METHODS: To improve the using rate of cfDNA template and decrease the PCR bias for liquid biopsy using urinary cfDNA, we developed a cell-free single-molecule unique primer extension resequencing (cf-SUPER) technology which was done for 29 matched urinary cfDNA and tumor DNA samples of bladder cancer patients to evaluate consistency of mutation profiles. Then, a 22 high mutational frequence genes was selected to form an uriprier panel, which was analyzed in 100 patients (47 bladder cancer cases and 53 controls) using cf-SUPER technology. This performance of the technology was evaluated using bioinformatic tools and clinical samples. RESULTS: The study showed that cf-SUPER technology can accurately detect mutations with allele fractions even low as 0.01% and the DNA input as low as 1 ng. The consistency of mutation profiles and clinical pathological diagnose between 29 matched urinary cfDNA and tumor DNA samples was respectively 82.76% and 89.66% by using cf-SUPER technology. Using cf-SUPER technology, the sensitivity and specificity were 98%, 94% respectively for uriprier panel in non-invasive test. CONCLUSIONS: The preliminary work shows that cf-SUPER technology will be a promising method for liquid biopsy. Focusing urinary cfDNA, the non-invasive diagnose and monitoring of bladder cancer can come true by using cf-SUPER technology.
RESUMO
Detection of chromosome copy number variation (CNV) plays an important role in the diagnosis of patients with unexplained clinical symptoms and for the identification of chromosome disease syndromes in the established fetus. In current clinical practice, karyotyping, in conjunction with array-based methods, is the gold standard for detection of CNV. To increase accessibility and reduce patient costs for diagnostic CNV tests, we speculated that next-generation sequencing methods could provide a similar degree of sensitivity and specificity as commercial arrays. CNV in patient samples was assessed on a medium-density single nucleotide polymorphism array and by low-coverage massively parallel CNV sequencing (CNV-seq), with mate pair sequencing used to confirm selected CNV deletion breakpoints. A total of 10 ng of input DNA was sufficient for accurate CNV-seq diagnosis, although 50 ng was optimal. Validation studies of samples with small CNVs showed that CNV-seq was specific and reproducible, suggesting that CNV-seq may have a potential genome resolution of approximately 0.1 Mb. In a blinded study of 72 samples with known gross and submicroscopic CNVs originally detected by single nucleotide polymorphism array, there was high diagnostic concordance with CNV-seq. We conclude that CNV-seq is a viable alternative to arrays for the diagnosis of chromosome disease syndromes.