Hybridization In Prenatal Diagnosis Research Articles

Evaluation of the practical applications of fluorescence in situ hybridization in the prenatal diagnosis of positive noninvasive prenatal screenings

Objective To investigate the application value and limitations of fluorescence in situ hybridization (FISH) in prenatal diagnosis of positive results for trisomies 13, 18, 21 (T13, T18, T21) and sex chromosome aneuploidies (SCAs) indicated by noninvasive prenatal screening (NIPS). Methods Samples from women who underwent prenatal diagnosis for the indication of positive NIPS of T13, T18, T21, and SCAs were collected. Each sample was split into two for both karyotype analysis and FISH analysis. The efficiency and consistency of FISH were assessed for the detection of chromosome abnormalities in the indications of positive NIPS results compared with karyotyping. Results A total of 649 pregnant women who scored positive for clinical significance of fetal chromosome abnormalities by NIPS were enrolled in our study, including T 13 (6%), T18 (14.3%), T21 (44.7%), SCAs (35.0%). From the following diagnostic test, the positive predictive value (PPV) of NIPS for T13, T18, T21, and SCAs was 17.9, 60.2, 89.3, and 43.6% respectively. FISH analysis was successful in all samples. Compared with karyotyping, the sensitivity and specificity were 98.3 and 100%, respectively. 95.7% (621/649) were fully concordant with karyotyping. 3.2% (21/649) cases were incompletely concordant with the karyotyping, among these cases, the FISH analysis identified all the aneuploidies, but karyotyping analysis provided more information about the chromosomal structure. There were 7 cases (1.1%, 7/649) of anomalies diagnosed by karyotype but missed out by FISH, all of which occurred in cases with the indication of SCAs. If the indications were confined to cases with a positive NIPS of T13, T18, T21, the diagnostic consistency of the two methods almost perfectly agree, and all the aneuploidies were detected by the FISH assay. FISH analysis was highly consistent in determining whether the fetus was euploid or not in the prenatal diagnosis for the patients with positive NIPS results compared with karyotyping (kappa= 0.976, p < .01). Conclusion For the prenatal diagnostic indications of positive NIPS of T13, T18, T21, and SCAs, FISH was equally efficacious in identifying aneuploidies and provided a quick diagnosis to alleviate anxiety. However, the missed risk of FISH analysis for structural chromosomal abnormalities should be taken seriously and fully informed during genetic counseling.

Investigation of the diagnostic value of chromosome analysis and bacterial artificial chromosome-based array comparative genomic hybridization in prenatal diagnosis

To investigate the diagnostic value of bacterial artificial chromosome (BAC)-based array comparative genomic hybridization (CGH) and chromosome analysis in prenatal diagnosis. This study included the chromosome analysis and BAC-based array CGH analysis of 140 amniocentesis samples with prenatal diagnosis indications. Karyotype analysis showed trisomy 21 in 4 patients, trisomy 18 in 5 patients, monosomy X in 1 patient, and other anomalies in 3 patients. The BAC-based array CGH analysis showed 4 patients with trisomy 21, 4 patients with trisomy 18, and 1 patient with monosomy X as a numerical chromosome anomaly, while partial duplication was observed in chromosome 14 in 1 case as a structural anomaly. The array CGH is the most effective method available to complement cases where chromosome analysis, a gold standard in prenatal diagnosis, proves to be insufficient. Considering the inherent limitations of both methods, complementary features should be introduced in order to be able to give the most accurate data at the right time.

Predictors for Choosing Array-Comparative Genomic Hybridization for Prenatal Diagnosis

Predictors for Choosing Array-Comparative Genomic Hybridization for Prenatal Diagnosis

Experience With Microarray-Based Comparative Genomic Hybridization for Prenatal Diagnosis in Over 5000 Pregnancies

Objective To demonstrate the usefulness of microarray testing in prenatal diagnosis based on our laboratory experience.

Clinical utility of array comparative genomic hybridisation for prenatal diagnosis: a cohort study of 3171 pregnancies

Clinical utility of array comparative genomic hybridisation for prenatal diagnosis: a cohort study of 3171 pregnancies

Clinical Utility of Array Comparative Genomic Hybridisation for Prenatal Diagnosis

Please cite this paper as: Lee C, Lin S, Lin C, Shih J, Lin T, Su Y. Clinical utility of array comparative genomic hybridisation for prenatal diagnosis: a cohort study of 3171 pregnancies. BJOG 2012;119:614–625. Objective To evaluate the clinical value of prenatal array comparative genomic hybridisation (CGH) in screening for submicroscopic genomic imbalances. Design Cross-sectional study. Setting Tertiary referral centre. Population From June 2008 to February 2011, 3171 fetuses underwent prenatal array CGH testing and karyotyping at the National Taiwan University Hospital. Indications for invasive prenatal diagnosis included abnormal karyotype, abnormal ultrasound, advanced maternal age and parental anxiety. Methods In all, 2497 fetuses were screened with 1-Mb resolution bacterial artificial chromosome array-based CGH, and 674 fetuses with 60-K oligonucleotide array-based CGH. Multiplex ligation-dependent probe amplification, fluorescence in situ hybridization, or 105-K oligonucleotide array CGH provided further confirmation. Main outcome measure Copy number variations identified by array CGH. Results Array CGH detected numerical chromosome anomalies in 37 (1.2%) fetuses, microdeletion/duplication in 34 (1.1%) fetuses, large deletion/duplication in 13 (0.4%) fetuses, benign copy number changes in 13 (0.4%) fetuses and variation of unknown clinical significance in five (0.2%) fetuses. Array CGH was effective in identifying submicroscopic genomic imbalance in fetuses with de novo balance translocations (2/17, 1.8%), supernumerary marker chromosomes (3/6, 50%), and abnormal prenatal ultrasound findings (33/194, 17.0%). Array CGH detected microdeletions/duplications in 12 fetuses with normal karyotype. Conclusion Prenatal array CGH is effective in screening for submicroscopic genomic imbalance. Array CGH may add 8.2% to the diagnostic field, compared with conventional karyotyping, for fetuses with abnormal ultrasound results, and is particularly useful in fetuses with karyotypic balanced translocation or marker chromosomes. There is a 0.52% baseline risk of submicroscopic genomic imbalance, even in women with an uneventful prenatal examination.

Array comparative genomic hybridization in prenatal diagnosis of first trimester pregnancies at high risk for chromosomal anomalies

ObjectiveTo describe the diagnostic performance of array comparative genomic hybridization (aCGH) as a potential first line diagnostic method in first trimester high risk pregnancies.MethodIn a retrospective study we performed aCGH using a targeted array BAC platform (Constitutional Chip® 4.0, PerkinElmer, Turku Finland, median resolution 600 kB) and the Affymetrix Cytogenetics® Whole Genome 2.7 M array (at a resolution of 400kB) on 100 anonymized prenatal samples from first trimester high risk pregnancies with normal conventional karyotype. We studied the technical feasibility and turn-around-time as well as the detection rate of pathogenic submicroscopic chromosome anomalies and CNVs of unknown significance.ResultsWe obtained results in 98 of 100 samples in 3 to a maximum of 5 days after DNA extraction. At the given resolution we did not identify any additional pathogenic CNVs but two CNVs of unknown significance in the chromosomal regions 1q21.1q21.2 (deletion) and 5p15.33 (duplication) (2%).ConclusionIn accordance with a growing number of reports this study supports the concept that aCGH at a resolution of 400-600kB may be used as a first line prenatal diagnostic test with high diagnostic safety and rapid turn-around time in high-risk first trimester pregnancies. Detection rate of CNVs of unknown significance, considered as a major hindrance for replacing conventional karyotyping by aCGH, is 2%, but the diagnosis of additional submicroscopic anomalies in this heterogeneous group of patients seems to be rare.

Current limitations and difficulties in application of microarray comparative genomic hybridization in prenatal diagnosis

Subchromosomal abnormalities can be positioned by the detection of copy number variation (CNV) using microarray comparative genomic hybridization (aCGH). aCGH has become a powerful tool in understanding the association between gene and genetic etiology in both research and clinical laboratories. Meanwhile as a new technique, controversies inevitably arose in its clinical application. As for the phenotype of CNV, little has been disclosed. For the clinicians, the difficulty in explanation of the CNV to the patients is obvious, which makes many doctors refuse to use aCGH for clinical diagnosis. Customized arrays have been exploited to decrease the uncertainty and efforts to search for a balance between overloaded information and insufficient information have been made. The purpose of this review is to discuss the current limitations and difficulties in application of aCGH in prenatal diagnosis and its application prospect from the point of a clinician.

ACOG Committee Opinion No. 446: Array Comparative Genomic Hybridization in Prenatal Diagnosis

The widespread use of array comparative genomic hybridization (CGH)for the diagnosis of genomic rearrangements in children with idiopathic mental retardation,developmental delay, and multiple congenital anomalies has spurred interest in applying array CGH technology to prenatal diagnosis. The use of array CGH technology in prenatal diagnosis is currently limited by several factors, including the inability to detect balanced chromosomal rearrangements, the detection of copy number variations of uncertain clinical significance, and significantly higher costs than conventional karyotype analysis. Although array CGH has distinct advantages over classic cytogenetics in certain applications, the technology is not currently a replacement for classic cytogenetics in prenatal diagnosis.

Application of fluorescence in situ hybridization in prenatal diagnosis of complex chromosomal abnormalities

To investigate the application of fluorescence in situ hybridization (FISH) technique in prenatal diagnosis of complex chromosomal abnormalities. Eleven prenatal diagnosis cases (8 from amniocentesis and 3 from cord blood) with complex chromosomal abnormalities detected by routine G-banding, were further analyzed by FISH. The FISH technique confirmed the results of balanced chromosome rearrangements detected by G-banding, and clarified the structure of the derivative chromosomes in the 3 amniocentesis samples and the origin of the mark chromosomes in the 2 cord blood samples. FISH can be used to diagnose the complex chromosomal abnormalities accurately in prenatal diagnosis, and can provide very useful genetic information for clinical diagnosis and treatment.

Clinical application of microarray-based comparative genomic hybridization in prenatal diagnosis

Karyotype analysis on amniotic fluid samples or chorionic villi has limited resolution and there is a delay between sampling and results. Therefore, invasive prenatal diagnosis has been reserved for pregnancies that are at increased risk for a defined genetic disorder, or for common aneuploidies found in liveborns. However, more than 70 disorders are now known to be associated with birth defects or developmental problems that are caused by deletion or duplication of a small chromosomal segment. These conditions and aneuploidies can be detected by array-based comparative genomic hybridization (CGH), which can evaluate the copy number of thousands of genomic regions simultaneously in a single assay. We review current knowledge on benign and pathological genomic copy number variants, principles of array CGH and its use for discovery and diagnosis of genetic diseases. Array CGH has already revolutionized genetic diagnosis in children and adults and is being used increasingly for prenatal diagnosis.

High‐resolution array genomic hybridization in prenatal diagnosis

Array genomic hybridization (AGH) can detect chromosomal gains or losses that are 100 times smaller than those identifiable by conventional cytogenetic methods. Genome-wide AGH can identify genomic imbalance that causes birth defects and mental retardation at least twice as frequently as conventional cytogenetic analysis. Using AGH as a prenatal test for fetal genomic imbalance offers the promise of detecting pathogenic gain or loss of genomic material more quickly and much more frequently than current methods. However, the chance of finding a result of uncertain clinical significance is much greater than with conventional cytogenetic analysis, and the benefit-cost ratio of doing AGH in addition to conventional cytogenetic analysis in pregnancies at high risk for Down syndrome is likely to be poor. Very little is known about the natural history and range of clinical variability associated with most pathogenic submicroscopic copy number variants (CNVs). It seems doubtful that patients can be adequately counseled for prenatal AGH testing in most cases because the risks and benefits are unknown. At present, AGH should be offered for prenatal diagnosis only if the pregnancy is at especially high risk of having a pathogenic CNV or if AGH is being done as part of a clinical trial.