Papers by Diane Van Opstal
Genomic array detects more pathogenic chromosome aberrations than conventional karyotyping (CK), ... more Genomic array detects more pathogenic chromosome aberrations than conventional karyotyping (CK), including genetic variants associated with a susceptibility for neurodevelopmental disorders; susceptibility loci (SL). Consensus regarding the scope of invasive prenatal diagnosis (PND) pregnant couples should be offered is lacking. This study examined pregnant couples' preferences, doubts and satisfaction regarding the scope of invasive PND. Eighty-two couples choosing prenatal screening (PNS) and 59 couples choosing invasive PND were offered a choice between 5 (comparable to CK) and 0.5 Mb resolution array analysis outcomes, the latter with or without reporting SL. A pre-test self-report questionnaire and post-test telephone interview assessed their choices in-depth. Actual (PND) and hypothetical (PNS) choices differed significantly (p < 0.001). Ninety-five percent of the couples in the PND group chose 0.5 Mb array, vs 69% in the PNS group. Seven percent of the PND group wished not to be informed of SL. Ninety percent was satisfied with their choice and wished to decide about the scope themselves. Pregnant couples wish to make their own choices regarding the scope of invasive PND. It therefore seems justified to offer them a choice in both the resolution of array and disclosure of SL.
Ultrasound in Obstetrics & Gynecology, 2017
On 3rd June 2016 Embase and PubMed databases were systematically searched for all relevant articl... more On 3rd June 2016 Embase and PubMed databases were systematically searched for all relevant articles on prevalence of pathogenic submicroscopic CNVs in fetuses tested due to advanced maternal age or parental anxiety. Relevant full text articles were analysed and based on the extracted data the prevalence of submicroscopic CNVs was calculated. Results: Meta-analysis was conducted in a pooled cohort of 10,614 fetuses based on the 10 largest studies (N > 300) of a total of 19 relevant studies. In 0.84%, 95%CI [0.55%, 1.30%] of fetuses a submicroscopic pathogenic aberration was detected prenatally. The onset/penetrance of the submicroscopic findings was studied in 10,314 fetuses out of 8 papers that presented aberrant cases with all necessary details. The prevalence of early onset syndromic disorders due to a submicroscopic aberration was calculated to be 1:270, based on 0.37%, 95%CI [0.27%, 0.52%] cases where aberrations were specified. Conclusions: This systematic review shows that a significant proportion of fetuses in a general pregnant population carry a submicroscopic pathogenic CNV. Based on these figures all women should be informed on their individual risk for all pathogenic chromosome aberrations and not only for common trisomies. P16.05 The influence of chromosomal microarray and NIPT on the diagnostic yield in 6,811 high-risk pregnancies without ultrasound anomalies
Prenatal Diagnosis, 2019
ObjectivePlacental cytogenetic studies may reveal the origin of discordant noninvasive prenatal t... more ObjectivePlacental cytogenetic studies may reveal the origin of discordant noninvasive prenatal testing (NIPT). We performed placental studies to elucidate discordances between NIPT showing a structural chromosome aberration and the fetus having a different chromosome aberration in three cases.MethodDiagnostic testing with genomic SNP microarray was performed in three cases with NIPT showing a duplication on 4q (case 1), a terminal deletion of 13q (case 2), and a terminal deletion of 15q (case 3). Placental studies involved SNP array analysis of cytotrophoblast and mesenchymal core of chorionic villi of four placental quadrants. Clinical follow‐up was performed as well.ResultsAmniotic fluid revealed a different structural chromosome aberration than predicted by NIPT: a terminal 2q deletion (case 1), a segmental uniparental isodisomy of 13q (case 2), and a terminal duplication of 15q and of 13q (case 3). Placental studies revealed the aberration detected with NIPT in the cytotrophobl...
Milder ovarian stimulation for in-vitro fertilization reduces aneuploidy in the human preimplanta... more Milder ovarian stimulation for in-vitro fertilization reduces aneuploidy in the human preimplantation
Reproductive Sciences, 2010
Genetics in Medicine, 2018
Using genome-wide noninvasive prenatal screening (NIPS), we detected a 20-megabase specific delet... more Using genome-wide noninvasive prenatal screening (NIPS), we detected a 20-megabase specific deletion starting at 10q25 in eight pregnancies. The deletion could not be confirmed by invasive testing. Since all 10(q25 → qter) deletions started close to the FRA10B fragile site in 10q25, we investigated whether the pregnant women were indeed carriers of FRA10B. Methods: We performed NIPS analysis for all autosomes using single-read sequencing. Analysis was done with the WISECONDOR algorithm. Culture of blood lymphocytes with bromodeoxyuridine was used to detect FRA10B expansions. Fluorescence in situ hybridization and array analysis were used to find maternal and/or fetal deletions. Results: We confirmed the presence of a FRA10B expansion in all four tested mothers. Fluorescence in situ hybridization and array analysis confirmed the presence of a maternal mosaic deletion of 10 (q25 → qter). Conclusion: The recurring 10(q25 → qter) deletion detected with NIPS is a false-positive result caused by a maternal low-level mosaic deletion associated with FRA10B expansions. This has important consequences for clinical follow-up, as invasive procedures are unnecessary. Expanded maternal FRA10B repeats should be added to the growing group of variants in the maternal genome that may cause false-positive NIPS results.
European journal of human genetics : EJHG, Dec 20, 2016
Oesophageal atresia (OA) with or without tracheoesophageal fistula (TOF) are rare anatomical cong... more Oesophageal atresia (OA) with or without tracheoesophageal fistula (TOF) are rare anatomical congenital malformations whose cause is unknown in over 90% of patients. A genetic background is suggested, and among the reported genetic defects are copy number variations (CNVs). We hypothesized that CNVs contribute to OA/TOF development. Quantifying their prevalence could aid in genetic diagnosis and clinical care strategies. Therefore, we profiled 375 patients in a combined Dutch, American and German cohort via genomic microarray and compared the CNV profiles with their unaffected parents and published control cohorts. We identified 167 rare CNVs containing genes (frequency<0.0005 in our in-house cohort). Eight rare CNVs - in six patients - were de novo, including one CNV previously associated with oesophageal disease. (hg19 chr7:g.(143820444_143839360)_(159119486_159138663)del) 1.55% of isolated OA/TOF patients and 1.62% of patients with additional congenital anomalies had de novo C...
Prenatal Diagnosis, 1995
Trisomy 18 in direct chorionic villus preparations needs further investigation since the chromoso... more Trisomy 18 in direct chorionic villus preparations needs further investigation since the chromosome abnormality may be confined to the placenta and may not represent the actual fetal karyotype. We performed, retrospectively, fluorescent in situ hybridization (FISH) with the chromosome 18 centromere probe (L1.84) on interphase nuclei of destained slides of all cases of full trisomy 18 (n=22) and mosaic trisomy 18 (n=8) detected among 7600 first-trimester chorionic villus samples during an 8-year period (1985-1992). More nuclei displaying three signals were encountered in cases of full and mosaic trisomy 18 contirmed in fetal tissue than in non-confirmed cases. FISH can be useful for the verification of trisomy 18 in direct chorionic villus preparations. KEY womsTrisomy 18, chorionic villi, confined placental mosaicism, fluorescent in situ hybridization.
Prenatal Diagnosis, 2001
ABSTRACT Fluorescence in situ hybridization (FISH) on uncultured amniotic fluid (AF) cells is a w... more ABSTRACT Fluorescence in situ hybridization (FISH) on uncultured amniotic fluid (AF) cells is a widespread technique for the rapid prenatal detection of specific chromosome aberrations. During a 6-year period (1993-1998) we used FISH for quick follow-up investigations in uncultured AF cells after finding an uncertain chromosome aberration in a first chorionic villus (CV) or AF sample in 79 cases. These FISH results were compared with conventional cytogenetic results of the AF cell cultures in all cases. We found discrepant FISH and cytogenetic results in four instances. In general, FISH on uncultured AF cells proved to be a reliable technique for the rapid differentiation between confined placental mosaicism and true fetal mosaicism, and between pseudomosaicism and true mosaicism, respectively. Uncultured cells may sometimes even better reflect chromosomal mosaicism than cultured cells, since they are not subject to culture induced selection mechanisms. However, we found evidence that exceptional cases of tissue confined mosaicism may go undetected in uncultured cells.
Prenatal Diagnosis, 1995
A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as ... more A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as the well-known accessory isochromosome 12p and a supernumerary single 12p marker in 17/24 and 6/24 clones of cultured amniotic fluid cells, respectively. The chromosomal nature of both marker chromosomes was investigated in cultured amnictic fluid cells by fluorescent in situ hybridization with various probes: the 12-centromeric probes pa12H8 and D12Z3, a whole chromosome 12 paint, and the chromosome 12pspecific paint M28. DNA analysis revealed a maternal origin of the extra 12p material. After counselling, the parents requested termination of pregnancy. Inspection and autopsy of the fetus revealed many of the dysmorphisms and internal structural abnormalities of the Pallister-Killian syndrome.
Prenatal Diagnosis, 1995
Fluorescent in situ hybridization (FISH) with a 21qll-specific probe (CB2lcl) consisting of three... more Fluorescent in situ hybridization (FISH) with a 21qll-specific probe (CB2lcl) consisting of three non-overlapping cosmids has been applied to interphase amniocytes of pregnancies at increased risk for fetal aneuploidy (N = 7 8) and to interphase lymphocytes, cultured and uncultured, of patients referred for Down syndrome (N=19 and 28, respectively). In the uncultured amniocytes, six chromosome aberrations were detected: three cases of trisomy 21, a triploidy, a de novo 46,XX,t(21q21q), and a mosaic 46,XY/47,XY,+dic(2l)(ql1)/48,XY,+dic(2l)(ql l), +de1(2l)(q11). In 15 cultured and 20 uncultured blood samples, FISH correctly diagnosed trisomy 21 (full or mosaic) at the interphase level, which was confirmed in all cases by subsequent karyotyping. Because of specific and strong signals in interphase nuclei, CB2lcl appears to be a useful tool for the rapid detection of chromosome 21 abnormalities.
Prenatal Diagnosis, 1998
In the population of children born after prenatal cytogenetic investigation in chorionic villi at... more In the population of children born after prenatal cytogenetic investigation in chorionic villi at our department from 1992 to 1995 (N = 3940), three are known to us with uniparental disomy. One case of maternal heterodisomy 16 was prenatally discovered because of trisomy 16 in direct chorionic villi with subsequently normal amniotic fluid cells. The other two had normal karyotypes in chorionic villi. Maternal heterodisomy 15 was postnatally detected in one of them because of Prader-Willi syndrome. Maternal hetero/isodisomy 16 was accidentally encountered in the other case in the course of prenatal DNA analysis of the tuberous sclerosis complex 2 region at 16p13.3. A model is presented for the understanding of the various combinations of karyotypes in direct chorionic villi, cultured chorionic villi and the fetus in the case of successful and unsuccessful trisomic zygote rescue.
Pediatric and Developmental Pathology, 2010
Chromosomal abnormalities are an important cause of multiple congenital anomalies (MCA). However,... more Chromosomal abnormalities are an important cause of multiple congenital anomalies (MCA). However, conventional cytogenetic analysis using culture is unsuccessful in 10% to 40% of the cases. The purpose of this study was to examine if retrospective chromosomal analysis was possible on paraffin-embedded autopsy material with new techniques, including comparative genomic hybridization (CGH) and fluorescent in situ hybridization (FISH). We investigated 92 patients, including 71 patients with MCA, 17 patients with an isolated congenital anomaly, and 4 normal controls, by conventional CGH analysis and/or FISH. The karyotype was known in 52 cases, of which 26 patients were normal and 26 had chromosomal anomalies. Comparative genomic hybridization or FISH confirmed all but 2 cases, which were not interpretable. In 40 patients the karyotype was unknown but could be analyzed successfully in 36 cases (90%) by CGH. In this series, we found 1 additional chromosomal aberration, 45,X (Turner syndr...
Molecular Cytogenetics, 2011
Background: Recent development of MLPA (Multiplex-Ligation-dependent Probe Amplification, MRC-Hol... more Background: Recent development of MLPA (Multiplex-Ligation-dependent Probe Amplification, MRC-Holland) and microarray technology allows detection of a wide range of new submicroscopic abnormalities. Publishing new cases and case reviews associated with both clinical abnormalities and a normal phenotype is of great value. Findings/results: We report on two phenotypically normal foetuses carrying a maternally-inherited interstitial submicroscopic abnormality of chromosome 18p11.32. Both abnormalities were found with the aneuploidy MLPA kit P095 during rapid aneuploidy detection, which was offered along with conventional karyotyping. Foetus 1 and its mother have a 1,7 Mb deletion and foetus 2 and its mother have a 1,9 Mb duplication. In both cases normal babies were born. We used the HumanCytoSNP-12 array of Illumina to visualize the CNVs and map the breakpoints. Conclusions: We suggest that a CNV at 18p11.32 (528,050-2,337,486) may represent a new benign euchromatic variant.
Human Reproduction Update, 2004
Assisted reproduction and preimplantation genetic diagnosis (PGD) involve various complicated tec... more Assisted reproduction and preimplantation genetic diagnosis (PGD) involve various complicated techniques, each of them with its own problems. However, the greatest problem with PGD for chromosome abnormalities is not of a technical nature but is a biological phenomenon: chromosomal mosaicism in the cleavage stage embryo. Here, we present a hypothetical, quantitative model for the development of chromosomally normal, abnormal and mosaic embryos. The arising of mosaicism in 2±8-cell embryos was described by a binomial probability model on the occurrence of mitotic events inducing chromosomal changes in the blastomeres. This model converted the`mean' rate of mosaicism found in cross-sectional studies (60%) into an equal rate of mosaic embryos at arrival at the 8-cell stage (59.8%). The disappearance of >90% of the mosaic embryos or the mosaicism itself from surviving embryos during the morula stage was explained by mitotic arrest of most of the mitotically changed cells under increasing cell cycle control. In our model, 25.9 and 14.3% of the embryos at the 8-cell stage are normal and abnormal respectively. The remaining 59.8% of the embryo shows mosaicism: 34.6% of abnormal/normal cells and 25.2% of abnormal/abnormal cells. The high proportion of abnormal and mosaic embryos together explains the high rate of abnormal laboratory ®ndings in PGD for chromosomal abnormalities and aneuploidy screening. The poor representation of a 1-or 2-cell biopsy for the 7-or 6-cell post-biopsy embryo in the case of mosaicism explains the high rate of false-negative and false-positive results.
Human Reproduction, 2010
Post-zygotic chromosome segregation errors are very common in human embryos after in vitro fertil... more Post-zygotic chromosome segregation errors are very common in human embryos after in vitro fertilization, resulting in mosaic embryos. However, the significance of mosaicism for the developmental potential of early embryos is unknown. We assessed chromosomal constitution and development of embryos from compaction to the peri-implantation stage. methods: From 112 cryopreserved Day 4 human embryos donated for research, 21 were immediately fixed and all cells were analysed by fluorescent in situ hybridization (FISH) for chromosomes 1, 7, 13, 15, 16, 18, 21, 22, X and Y. The remaining 91 embryos were thawed, with 54 embryos undergoing biopsy of one or two cells which were fixed and analysed by FISH. Biopsied embryos were kept in standard culture conditions for 24 h. Embryos arrested before cavitation (n ¼ 24) were fixed whereas developing Day 5 blastocysts (n ¼ 24) were cocultured for a further 72 h on an endometrial monolayer followed by fixation. Cell numbers were counted and all nuclei were analysed by FISH. Data from a previous FISH analysis on cryopreserved good-quality Day 5 blastocysts (n ¼ 36) were also included in the present study. results: FISH analysis was successful for 18 Day 4 fixed embryos and, according to our definition, 83% were mosaic and 11% showed a chaotic chromosomal constitution. FISH analysis of two blastomeres from Day 4 developing embryos showed that 54% were mosaic, 40% were normal and 6% were abnormal. Analysis of Day 4, 5 and 8 whole embryos showed a decrease in incidence of mosaicism over time, from 83% on Day 4 to 42% on Day 8. A significant positive correlation was observed between the total cell number and the percentage of normal cells in developing Day 5 and Day 8 embryos but not in developing Day 4 or embryos arrested before cavitation. conclusions: These data suggest that both the developmental arrest of a significant proportion of mosaic embryos on Day 4, and the cell death or reduced proliferation of aneuploid cells within an embryo may be responsible for the observed decrease of aneuploid blastomeres from compaction to the peri-implantation stage.
Human Reproduction, 1997
nine chromosome aberrations found in a series of prenatally investigated ICSI pregnancies.
Human Mutation, 2013
Using whole-genome array testing instead of karyotyping in prenatal diagnosis for all indications... more Using whole-genome array testing instead of karyotyping in prenatal diagnosis for all indications may be desirable because of the higher diagnostic yield and shorter reporting time. The goal of this research was finding the optimal array resolution that could replace routine prenatal karyotyping in cases without ultrasound abnormalities, for example, referred for advanced maternal age or abnormal first trimester screening. As variants of unknown clinical significance (VOUS), if reported, might complicate decision-making about continuation of pregnancy, such an optimal array resolution should have a high abnormality detection rate and reveal a minimal amount of VOUS. The array data of 465 fetuses were retrospectively evaluated with several resolution levels, and the Decipher microdeletion/microduplication syndrome list was reviewed to assess what could be theoretically missed with a lower resolution. A 0.5-Mb resolution showed a high diagnostic yield potential and significantly minimized the number of VOUS. Based on our experience, we recommend genomic SNP array as a first-tier test in prenatal diagnosis. The resolution should be chosen based on the indication. In cases of fetal ultrasound abnormalities or intrauterine fetal death (IUFD), high-resolution analysis should be done. In other cases, we advise replacing karyotyping by SNP array analysis with 0.5 Mb resolution.
Fetal Diagnosis and Therapy, 2001
Objective: Investigation of the normal frequency of tetraploid metaphases in semidirect (STC) and... more Objective: Investigation of the normal frequency of tetraploid metaphases in semidirect (STC) and cultured (LTC) chorionic villi. Methods: Fifty metaphases in STC- and in LTC-villi slides of 100 women of advanced maternal age were screened for tetraploidy. Results: Up to three tetraploid metaphases were encountered in 27% of the STC-villi preparations; the scores fitted a Poisson distribution. In all LTC-villi preparations tetraploid cells were seen; the scores fitted a log-Gaussian distribution. Conclusions: On the basis of these distributions, we propose a protocol for the management of tetraploid metaphases in chorionic villi, strongly reducing the number of prenatal follow-up investigations.
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Papers by Diane Van Opstal