Psychological impact of additional findings detected by genome-wide Non-Invasive Prenatal Testing (NIPT): TRIDENT-2 study.

In the Netherlands, genome-wide non-invasive prenatal testing (NIPT) is offered to all pregnant women as part of the nationwide TRIDENT-2 study. Findings other than trisomy 21, 18, or 13, which are called "additional findings", are reported only on request of the pregnant woman. This study examined: (1) women's pre-test perceptions and reasons to opt for additional findings and (2) women's experiences with- and the psychological impact of being informed about an additional finding. A questionnaire, consisting of the anxiety measure State-Trait Anxiety Inventory (STAI), distress measure Impact of Event Scale (IES) and questions developed specifically for this study, was retrospectively administered to 402 women who received an additional finding. A total of 227 (56.5%) women completed the questionnaire. Most (60.2%) chose to know additional findings because they wanted as much information as possible about the health of their fetus. Almost all (92%) stated that receiving the additional finding was unexpected, a shock, and/or they were in disbelief, for 85% it caused a lot of worry. Post-test, high anxiety (STAI) levels were reported in 15.5% of women, and 7.5% reported severe distress (IES). Women who gave birth to an affected child (n = 10) experienced most psychological impact (STAI and IES). Eighty-six percent of women with a fetal aberration would opt for additional findings again, compared to 49.2% of women whose result was confined to the placenta. Pre-test counseling should focus on explaining the different results NIPT can generate. Post-test counseling should focus on guiding pregnant women through this uncertain and anxious time.

Limited additional value of karyotyping cultured amniotic fluid cell colonies in addition to microarray on uncultured cells for confirmation of abnormal non-invasive prenatal testing results.

OBJECTIVES: Non-invasive prenatal testing (NIPT) allows the detection of placental chromosome aberrations. To verify whether the fetus also has the chromosome aberration, diagnostic follow-up testing is required. The aim of this retrospective study was to assess the added value of analyzing amniotic fluid (AF) cell cultures in addition to uncultured AF cells for the detection of fetal mosaicism. METHOD: NIPT was performed as part of the Dutch TRIDENT study. Cytogenetic studies in uncultured AF were performed using single nucleotide polymorphism (SNP)-array. Cultured AF cell colonies (in situ method) were investigated with fluorescent in situ hybridization and/or karyotyping. Clinical outcome data were collected in cases with discordant results. RESULTS: Between April 2014 and December 2021, 368 amniocenteses were performed after a chromosomal aberration was detected with NIPT. Excluding 134 cases of common aneuploidies (confirmed by quantitative fluorescence polymerase chain reaction), 29 cases with investigation of uncultured cells only and 1 case without informed consent, 204 cases were eligible for this study. In 196 (96%) cases, the results in uncultured and cultured cells were concordant normal, abnormal or mosaic. Five cases (2%) showed mosaicism in cultured AF cells, whereas uncultured AF cells were normal. Two (1%) of these, one mosaic trisomy 13 and one mosaic trisomy 16, were considered true fetal mosaics. CONCLUSION: The added value of investigating AF cell cultures in addition to uncultured cells is limited to two of 204 (1%) cases in which true fetal mosaicsm would otherwise be missed. The clinical relevance of one (trisomy 13) remained unknown and the other case also showed ultrasound anomalies, which determined pregnancy management. This seems to justify limiting prenatal cytogenetic confirmatory testing to SNP arrays on uncultured AF cells, considerably shortening the reporting time.

Informed choice and routinization of the second-trimester anomaly scan: a national cohort study in the Netherlands.

BACKGROUND: Since 2007 all pregnant women in the Netherlands are offered the second-trimester anomaly scan (SAS) in a nationwide prenatal screening program. This study aims to assess the level of informed choice of women opting for the SAS and to evaluate the presence of routinization 16 years after its implementation. It further explores decisional conflict and women's decision making. METHODS: This prospective national survey study consisted of an online questionnaire which was completed after prenatal counseling and before undergoing the SAS. Informed choice was measured by the adapted multidimensional measure of informed choice (MMIC) and was defined in case women were classified as value-consistent, if their decision for the SAS was deliberated and made with sufficient knowledge. RESULTS: A total of 894/1167 (76.6%) women completed the questionnaire. Overall, 54.8% made an informed choice, 89.6% had good knowledge, 59.8% had deliberated their choice and 92.7% held a positive attitude towards the SAS. Women with low educational attainment (p=0.004) or respondents of non-Western descent (p=0.038) were less likely to make an informed choice. Decisional conflict was low, with a significantly lower decisional conflict score in women that made an informed choice (p<0.001). Most respondents (97.9%) did not perceive pressure to undergo the SAS. CONCLUSIONS: Our study showed a relatively low rate of informed choice for the SAS, due to absence of deliberation. Therefore, some routinization seem to be present in the Netherlands. However, most women had sufficient knowledge, did not perceive pressure and experienced low decisional conflict.

Current practice of first-trimester ultrasound screening for structural fetal anomalies in developed countries.

OBJECTIVES: First-trimester ultrasound screening is increasingly performed to detect fetal anomalies early in pregnancy, aiming to enhance reproductive autonomy for future parents. This study aims to display the current practice of first-trimester ultrasound screening in developed countries. METHOD: An online survey among 47 prenatal screening experts in developed countries. RESULTS: First-trimester structural anomaly screening is available in 30 of the 33 countries and is mostly offered to all women with generally high uptakes. National protocols are available in 23/30 (76.7%) countries, but the extent of anatomy assessment varies. Monitoring of scan quality occurs in 43.3% of the countries. 23/43 (53.5%) of the respondents considered the quality of first-trimester ultrasound screening unequal in different regions of their country. CONCLUSIONS: First-trimester screening for structural fetal anomalies is widely offered in developed countries, but large differences are reported in availability and use of screening protocols, the extent of anatomy assessment, training and experience of sonographers and quality monitoring systems. Consequently, this results in an unequal offer to parents in developed countries, sometimes even within the same country. Furthermore, as offer and execution differ widely, this has to be taken into account when results of screening policies are scientifically published or compared.

Non-invasive prenatal testing (NIPT) in twin pregnancies affected by early single fetal demise: A systematic review of NIPT and vanishing twins.

The screening performance of non-invasive prenatal testing (NIPT) in vanishing twin (VT) pregnancies is relatively unknown. To close this knowledge gap, we conducted a systematic review of the available literature. Studies describing the test performance of NIPT for trisomy 21, 18, 13, sex chromosomes and additional findings in pregnancies with a VT were retrieved from a literature search with a publication date until October 4, 2022. The methodological quality of the studies was assessed with the quality assessment tool for diagnostic accuracy studies-2 (QUADAS-2). The screen positive rate of the pooled data and the pooled positive predictive value (PPV) were calculated using a random effects model. Seven studies, with cohort sizes ranging from 5 to 767, were included. The screen positive rate of the pooled data for trisomy 21 was 35/1592 (2.2%), with a PPV of 20% (confirmation in 7/35 cases [95% CI 9.8%-36%]). For trisomy 18, the screen positive rate was 13/1592 (0.91%) and the pooled PPV 25% [95% CI 1.3%-90%]. The screen positive rate for trisomy 13 was 7/1592 (0.44%) and confirmed in 0/7 cases (pooled PPV 0% [95% CI 0%-100%]). The screen positive rate for additional findings was 23/767 (2.9%), of which none could be confirmed. No discordant negative results were reported. There is insufficient data to fully evaluate NIPT performance in pregnancies with a VT. However, existing studies suggest that NIPT can successfully detect common autosomal aneuploidies in pregnancies affected by a VT but with a higher false positive rate. Further studies are needed to determine the optimal timing of NIPT in VT pregnancies.

A cross-country comparison of pregnant women's decision-making and perspectives when opting for non-invasive prenatal testing in the Netherlands and Belgium.

BACKGROUND: The Netherlands and Belgium have been among the first countries to offer non-invasive prenatal testing (NIPT) as a first-tier screening test. Despite similarities, differences exist in counseling modalities and test uptake. This study explored decision-making and perspectives of pregnant women who opted for NIPT in both countries. METHODS: A questionnaire study was performed among pregnant women in the Netherlands (NL) (n = 587) and Belgium (BE) (n = 444) opting for NIPT, including measures on informed choice, personal and societal perspectives on trisomy 21, 18 and 13 and pregnancy termination. RESULTS: Differences between Dutch and Belgian women were shown in the level of informed choice (NL: 83% vs. BE: 59%, p < 0.001), intention to terminate the pregnancy in case of confirmed trisomy 21 (NL: 51% vs. BE: 62%, p = 0.003) and trisomy 13/18 (NL: 80% vs. BE: 73%, p = 0.020). More Belgian women considered trisomy 21 a severe condition (NL: 64% vs. BE: 81%, p < 0.001). Belgian women more frequently indicated that they believed parents are judged for having a child with trisomy 21 (BE: 42% vs. NL: 16%, p < 0.001) and were less positive about quality of care and support for children with trisomy 21 (BE: 23% vs. NL: 62%, p < 0.001). CONCLUSION: Differences in women's decision-making regarding NIPT and the conditions screened for may be influenced by counseling aspects and country-specific societal and cultural contexts.

Experiences of pregnant women with genome-wide non-invasive prenatal testing in a national screening program.

Pregnant women's perspectives should be included in the dialogue surrounding the expanding offers of non-invasive prenatal testing (NIPT), especially now that technological possibilities are rapidly increasing. This study evaluated women's experiences with the offer of genome-wide (GW) first-tier NIPT in a national screening program. A nationwide pre-and post-test questionnaire was completed by 473 pregnant women choosing between targeted NIPT (trisomies 21, 18 and 13 only) and GW-NIPT (also other findings) within the Dutch TRIDENT-2 study. Measures included satisfaction, reasons for or against choosing GW-NIPT, anxiety, and opinion on the future scope of NIPT. Most respondents (90.4%) were glad to have been offered the choice between GW-NIPT and targeted NIPT; 76.5% chose GW-NIPT. Main reasons to choose GW-NIPT were 'wanting as much information as possible regarding the child's health' (38.6%) and 'to be prepared for everything' (23.8%). Main reasons to choose targeted NIPT were 'avoiding uncertain results/outcomes' (33.7%) and 'not wanting to unnecessarily worry' (32.6%). Nearly all respondents received a low-risk NIPT result (98.7%). No differences were found in anxiety between women choosing GW-NIPT and targeted NIPT. Most respondents were favorable toward future prenatal screening for a range of conditions, including life-threatening disorders, mental disabilities, disorders treatable in pregnancy and severe physical disabilities, regardless of their choice for GW-NIPT or targeted NIPT. In conclusion, women who chose first-tier NIPT were satisfied with the choice between GW-NIPT and targeted NIPT, and most women were favorable toward a broader future screening offer. Our results contribute to the debate concerning the expansion of NIPT.

Factors involved in the decision to decline prenatal screening with noninvasive prenatal testing (NIPT).

OBJECTIVE: To investigate factors involved in the decision to decline prenatal screening with noninvasive prenatal testing (NIPT). METHOD: A questionnaire study was conducted among 219 pregnant women in the Netherlands who had declined prenatal screening with NIPT (TRIDENT-2 study). Respondents were selectively recruited from three hospitals and 19 midwifery practices, primarily located in or near socioeconomically disadvantaged neighborhoods. 44.3% of the respondents were of non-Western ethnic origin and 64.4% were religious. RESULTS: Most respondents (77.2%) found the decision to decline NIPT easy to make, and 59.8% had already made the decision before information about NIPT was offered. These respondents were more often religious, multigravida, and had adequate health literacy. The main reasons to decline NIPT were "I would never terminate my pregnancy" (57.1%) and "every child is welcome" (56.2%). For 16.9% of respondents, the out-of-pocket costs (175 euros) played a role in the decision, and the women in this group were more often nonreligious, primigravida, and had inadequate health literacy. CONCLUSION: The primary factors involved in the decision to decline NIPT were related to personal values and beliefs, consistent with autonomous choice. Out-of-pocket costs of NIPT hinder equal access for some pregnant women.

The pZRS non-coding regulatory mutation resulting in triphalangeal thumb-polysyndactyly syndrome changes the pattern of local interactions.

Herein, we report on a large Polish family presenting with a classical triphalangeal thumb-polysyndactyly syndrome (TPT-PS). This rare congenital limb anomaly is generally caused by microduplications encompassing the Sonic Hedgehog (SHH) limb enhancer, termed the zone of polarizing activity (ZPA) regulatory sequence (ZRS). Recently, a pathogenic variant in the pre-ZRS (pZRS), a conserved sequence located near the ZRS, has been described in a TPT-PS Dutch family. We performed targeted ZRS sequencing, array comparative genomic hybridization, and whole-exome sequencing. Next, we sequenced the recently described pZRS region. Finally, we performed a circular chromatin conformation capture-sequencing (4C-seq) assay on skin fibroblasts of one affected family member and control samples to examine potential alterations in the SHH regulatory domain and functionally characterize the identified variant. We found that all affected individuals shared a recently identified pathogenic point mutation in the pZRS region: NC_000007.14:g.156792782C>G (GRCh38/hg38), which is the same as in the Dutch family. The results of 4C-seq experiments revealed increased interactions within the whole SHH regulatory domain (SHH-LMBR1 TAD) in the patient compared to controls. Our study expands the number of TPT-PS families carrying a pathogenic alteration of the pZRS and underlines the importance of routine pZRS sequencing in the genetic diagnostics of patients with TPT-PS or similar phenotypes. The pathogenic mutation causative for TPT-PS in our patient gave rise to increased interactions within the SHH regulatory domain in yet unknown mechanism.

Clinical impact of additional findings detected by genome-wide non-invasive prenatal testing: Follow-up results of the TRIDENT-2 study.

In the TRIDENT-2 study, all pregnant women in the Netherlands are offered genome-wide non-invasive prenatal testing (GW-NIPT) with a choice of receiving either full screening or screening solely for common trisomies. Previous data showed that GW-NIPT can reliably detect common trisomies in the general obstetric population and that this test can also detect other chromosomal abnormalities (additional findings). However, evidence regarding the clinical impact of screening for additional findings is lacking. Therefore, we present follow-up results of the TRIDENT-2 study to determine this clinical impact based on the laboratory and perinatal outcomes of cases with additional findings. Between April 2017 and April 2019, additional findings were detected in 402/110,739 pregnancies (0.36%). For 358 cases, the origin was proven to be either fetal (n = 79; 22.1%), (assumed) confined placental mosaicism (CPM) (n = 189; 52.8%), or maternal (n = 90; 25.1%). For the remaining 44 (10.9%), the origin of the aberration could not be determined. Most fetal chromosomal aberrations were pathogenic and associated with severe clinical phenotypes (61/79; 77.2%). For CPM cases, occurrence of pre-eclampsia (8.5% [16/189] vs 0.5% [754/159,924]; RR 18.5), and birth weight <2.3rd percentile (13.6% [24/177] vs 2.5% [3,892/155,491]; RR 5.5) were significantly increased compared to the general obstetric population. Of the 90 maternal findings, 12 (13.3%) were malignancies and 32 (35.6%) (mosaic) pathogenic copy number variants, mostly associated with mild or no clinical phenotypes. Data from this large cohort study provide crucial information for deciding if and how to implement GW-NIPT in screening programs. Additionally, these data can inform the challenging interpretation, counseling, and follow-up of additional findings.

Nationwide implementation of the non-invasive prenatal test: Evaluation of a blended learning program for counselors.

This study assesses the results of a mandatory blended learning-program for counselors (e.g. midwives, sonographers, obstetricians) guiding national implementation of the Non-Invasive Prenatal Test (NIPT). We assessed counselors' 1) knowledge about prenatal aneuploidy screening, 2) factors associated with their knowledge (e.g. counselors' characteristics, attitudes towards NIPT), and 3) counselors' attitudes regarding the blended learning. A cross-sectional online pretest-posttest implementation survey was sent to all 2,813 Dutch prenatal counselors. Multivariate linear regression analyses were performed to identify associations between counselors' knowledge and e.g. their professional backgrounds, work experience and attitudes towards NIPT. At T0 and T1 1,635 and 913 counselors completed the survey, respectively. Overall results show an increased mean number of correct answered knowledge questions; 23/35 (66%) items at T0 and 28/37 (76%) items at T1. Knowledge gaps on highly specific topics remained. Work experience and secondary care work-setting were positively associated with a higher level of knowledge. Most counselors (74%) showed positive attitudes towards the blended learning program. The mandatory blended learning, along with learning by experience through implementation of NIPT, has facilitated an increase in counselors' knowledge and was well received. New implementations in healthcare may benefit from requiring blended learning for healthcare providers, especially if tailored to professionals' learning goals.

Noninvasive Prenatal Test Results Indicative of Maternal Malignancies: A Nationwide Genetic and Clinical Follow-Up Study.

PURPOSE: Noninvasive prenatal testing (NIPT) for fetal aneuploidy screening using cell-free DNA derived from maternal plasma can incidentally raise suspicion for cancer. Diagnostic routing after malignancy suspicious-NIPT faces many challenges. Here, we detail malignancy suspicious-NIPT cases, and describe the clinical characteristics, chromosomal aberrations, and diagnostic routing of the patients with a confirmed malignancy. Clinical lessons can be learned from our experience. METHODS: Patients with NIPT results indicative of a malignancy referred for tumor screening between April 2017 and April 2020 were retrospectively included from a Dutch nationwide NIPT implementation study, TRIDENT-2. NIPT profiles from patients with confirmed malignancies were reviewed, and the pattern of chromosomal aberrations related to tumor type was analyzed. We evaluated the diagnostic contribution of clinical and genetic examinations. RESULTS: Malignancy suspicious-NIPT results were reported in 0.03% after genome-wide NIPT, and malignancies confirmed in 16 patients (16/48, 33.3%). Multiple chromosomal aberrations were seen in 23 of 48 patients with genome-wide NIPT, and a malignancy was confirmed in 16 patients (16/23, 69.6%). After targeted NIPT, 0.005% malignancy suspicious-NIPT results were reported, in 2/3 patients a malignancy was confirmed. Different tumor types and stages were diagnosed, predominantly hematologic malignancies (12/18). NIPT data showed recurrent gains and losses in primary mediastinal B-cell lymphomas and classic Hodgkin lymphomas. Magnetic resonance imaging and computed tomography were most informative in diagnosing the malignancy. CONCLUSION: In 231,896 pregnant women, a low percentage (0.02%) of NIPT results were assessed as indicative of a maternal malignancy. However, when multiple chromosomal aberrations were found, the risk of a confirmed malignancy was considerably high. Referral for extensive oncologic examination is recommended, and may be guided by tumor-specific hallmarks in the NIPT profile.

Routinization of prenatal screening with the non-invasive prenatal test: pregnant women's perspectives.

Due to the favorable test characteristics of the non-invasive prenatal test (NIPT) in the screening of fetal aneuploidy, there has been a strong and growing demand for implementation. In the Netherlands, NIPT is offered within a governmentally supported screening program as a first-tier screening test for all pregnant women (TRIDENT-2 study). However, concerns have been raised that the test's favorable characteristics might lead to uncritical use, also referred to as routinization. This study addresses women's perspectives on prenatal screening with NIPT by evaluating three aspects related to routinization: informed choice, freedom to choose and (personal and societal) perspectives on Down syndrome. Nationwide, a questionnaire was completed by 751 pregnant women after receiving counseling for prenatal screening. Of the respondents, the majority (75.5%) made an informed choice for prenatal screening as measured by the multidimensional measure of informed choice (MMIC). Education level and religious affiliation were significant predictors of informed choice. The main reason to accept screening was "seeking reassurance" (25.5%), and the main reason to decline was "every child is welcome" (30.6%). The majority of respondents (87.7%) did not perceive societal pressure to test. Differences between test-acceptors and test-decliners in personal and societal perspectives on Down syndrome were found. Our study revealed high rates of informed decision-making and perceived freedom to choose regarding fetal aneuploidy screening, suggesting that there is little reason for concern about routinization of NIPT based on the perspectives of Dutch pregnant women. Our findings highlight the importance of responsible implementation of NIPT within a national screening program.

Non-invasive prenatal test uptake in socioeconomically disadvantaged neighborhoods.

OBJECTIVE: Non-Invasive Prenatal Testing (NIPT) is increasingly being implemented worldwide. In public health programs, equitable access to healthcare is a fundamental principle which also applies to fetal aneuploidy screening. However, the out-of-pocket costs of NIPT may lead to sociodemographic disparities in uptake of screening. This study assessed whether there is a difference in the uptake of NIPT in socioeconomically disadvantaged neighborhoods compared to all other neighborhoods in the Netherlands, where NIPT is implemented in a national screening program (TRIDENT-2 study). METHOD: NIPT uptake, postal code and age of 156,562 pregnant women who received pre-test counselling for prenatal screening in 2018 were retrieved from the national prenatal screening database. Postal codes were used as a proxy to categorize neighborhoods as being either socioeconomically disadvantaged or other. The out-of-pocket costs for NIPT were €175. RESULTS: NIPT uptake in socioeconomically disadvantaged neighborhoods was 20.3% whereas uptake in all other neighborhoods was 47.6% (p < 0.001). The difference in NIPT uptake between socioeconomic disadvantaged neighborhoods and other areas was smaller for the youngest maternal age-group (≤25 years) compared to other age-groups. CONCLUSION: The variation in uptake suggest underlying disparities in NIPT uptake, which undermines the goals of a national fetal aneuploidy screening program of providing reproductive autonomy and equitable access. This has ethical and policy implications for ensuring fair and responsible implementation of fetal aneuploidy screening.

Confined placental mosaicism and the association with pregnancy outcome and fetal growth: a review of the literature.

BACKGROUND: Chromosomal mosaicism can be detected in different stages of early life: in cleavage stage embryos, in blastocysts and biopsied cells from blastocysts during preimplantation genetic testing for aneuploidies (PGT-A) and later during prenatal testing, as well as after birth in cord blood. Mosaicism at all different stages can be associated with adverse pregnancy outcomes. There is an onward discussion about whether blastocysts diagnosed as chromosomally mosaic by PGT-A should be considered safe for transfer. An accurate diagnosis of mosaicism remains technically challenging and the fate of abnormal cells within an embryo remains largely unknown. However, if aneuploid cells persist in the extraembryonic tissues, they can give rise to confined placental mosaicism (CPM). Non-invasive prenatal testing (NIPT) uses cell-free (cf) DNA released from the placenta in maternal blood, facilitating the detection of CPM. In literature, conflicting evidence is found about whether CPM is associated with fetal growth restriction (FGR) and/or other pregnancy outcomes. This makes counselling for patients by clinicians challenging and more knowledge is needed for clinical decision and policy making. OBJECTIVE AND RATIONALE: The objective of this review is to evaluate the association between CPM and prenatal growth and adverse pregnancy outcomes. All relevant literature has been reviewed in order to achieve an overview on merged results exploring the relation between CPM and FGR and other adverse pregnancy outcomes. SEARCH METHODS: The following Medical Subject Headings (MESH) terms and all their synonyms were used: placental, trophoblast, cytotrophoblast, mosaicism, trisomy, fetal growth, birth weight, small for gestational age and fetal development. A search in Embase, PubMed, Medline Ovid, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) and Google Scholar databases was conducted. Relevant articles published until 16 July 2020 were critically analyzed and discussed. OUTCOMES: There were 823 articles found and screened based on their title/abstract. From these, 213 articles were selected and full text versions were obtained for a second selection, after which 70 publications were included and 328 cases (fetuses) were analyzed. For CPM in eight different chromosomes (of the total 14 analyzed), there was sufficient evidence that birth weight was often below the 5th percentile of fetal growth standards. FGR was reported in 71.7% of CPM cases and preterm birth (<37 weeks of delivery) was reported in 31.0% of cases. A high rate of structural fetal anomalies, 24.2%, in cases with CPM was also identified. High levels of mosaicism in CVS and presence of uniparental disomy (UPD) were significantly associated with adverse pregnancy outcomes. WIDER IMPLICATIONS: Based on the literature, the advice to clinicians is to monitor fetal growth intensively from first trimester onwards in case of CPM, especially when chromosome 2, 3, 7, 13, 15, 16 and 22 are involved. In addition to this, it is advised to examine the fetuses thoroughly for structural fetal anomalies and raise awareness of a higher chance of (possibly extreme) premature birth. Despite prematurity in nearly a fifth of cases, the long-term follow-up of CPM life borns seems to be positive. More understanding of the biological mechanisms behind CPM will help in prioritizing embryos for transfer after the detection of mosaicism in embryos through PGT-A.

Non-invasive prenatal testing (NIPT): societal pressure or freedom of choice? A vignette study of Dutch citizens' attitudes.

The introduction of the accurate and procedurally easy non-invasive prenatal test (NIPT) raises ethical concerns that public attitudes towards prenatal screening may change, leading to societal pressure to participate in aneuploidy screening. This study examined Dutch citizens' attitudes towards a pregnant woman's decision to (1) decline NIPT in the context of two different funding policies and (2) to terminate or continue a pregnancy affected by different disorders. The attitudes of 1096 respondents were assessed with the contrastive vignette method, using two pairs of vignettes about declining NIPT and termination of pregnancy. Most respondents either agreed with a woman's decision to decline NIPT or were neutral about it, stating that this decision should be made independently by women, and does not warrant judgement by others. Interestingly, funding policies did influence respondents' attitudes: significantly more respondents disagreed with declining NIPT when it was fully reimbursed. Respondents had similar attitudes to the vignettes on termination and continuation of pregnancy in case of Down's syndrome. In case of Edwards' or Patau's syndrome, however, significantly more respondents disagreed with continuation, citing the severity of the disorder and the child's best interests. This study demonstrates broad acknowledgement of women's freedom of choice in Dutch society; a finding that may help to rebut existing concerns about societal pressure for pregnant women to participate in prenatal screening. As the reimbursement policy and the scope of NIPT may influence people's attitudes and elicit moral judgements, however, maintaining freedom of choice warrants sustained efforts by health professionals and policy makers.

Variant type and position predict two distinct limb phenotypes in patients with GLI3-mediated polydactyly syndromes.

INTRODUCTION: Pathogenic DNA variants in the GLI-Kruppel family member 3 (GLI3) gene are known to cause multiple syndromes: for example, Greig syndrome, preaxial polydactyly-type 4 (PPD4) and Pallister-Hall syndrome. Out of these, Pallister-Hall is a different entity, but the distinction between Greig syndrome and PPD4 is less evident. Using latent class analysis (LCA), our study aimed to investigate the correlation between reported limb anomalies and the reported GLI3 variants in these GLI3-mediated polydactyly syndromes. We identified two subclasses of limb anomalies that relate to the underlying variant. METHODS: Both local and published cases were included for analysis. The presence of individual limb phenotypes was dichotomised and an exploratory LCA was performed. Distribution of phenotypes and genotypes over the classes were explored and subsequently the key predictors of latent class membership were correlated to the different clustered genotypes. RESULTS: 297 cases were identified with 127 different variants in the GLI3 gene. A two-class model was fitted revealing two subgroups of patients with anterior versus posterior anomalies. Posterior anomalies were observed in cases with truncating variants in the activator domain (postaxial polydactyly; hand, OR: 12.7; foot, OR: 33.9). Multivariate analysis supports these results (Beta: 1.467, p=0.013 and Beta: 2.548, p<0.001, respectively). Corpus callosum agenesis was significantly correlated to these variants (OR: 8.8, p<0.001). CONCLUSION: There are two distinct phenotypes within the GLI3-mediated polydactyly population: anteriorly and posteriorly orientated. Variants that likely produce haploinsufficiency are associated with anterior phenotypes. Posterior phenotypes are associated with truncating variants in the activator domain. Patients with these truncating variants have a greater risk for corpus callosum anomalies.

The potential diagnostic yield of whole exome sequencing in pregnancies complicated by fetal ultrasound anomalies.

INTRODUCTION: The aim of this retrospective cohort study was to determine the potential diagnostic yield of prenatal whole exome sequencing in fetuses with structural anomalies on expert ultrasound scans and normal chromosomal microarray results. MATERIAL AND METHODS: In the period 2013-2016, 391 pregnant women with fetal ultrasound anomalies who received normal chromosomal microarray results, were referred for additional genetic counseling and opted for additional molecular testing pre- and/or postnatally. Most of the couples received only a targeted molecular test and in 159 cases (40.7%) whole exome sequencing (broad gene panels or open exome) was performed. The results of these molecular tests were evaluated retrospectively, regardless of the time of the genetic diagnosis (prenatal or postnatal). RESULTS: In 76 of 391 fetuses (19.4%, 95% CI 15.8%-23.6%) molecular testing provided a genetic diagnosis with identification of (likely) pathogenic variants. In the majority of cases (91.1%, 73/76) the (likely) pathogenic variant would be detected by prenatal whole exome sequencing analysis. CONCLUSIONS: Our retrospective cohort study shows that prenatal whole exome sequencing, if offered by a clinical geneticist, in addition to chromosomal microarray, would notably increase the diagnostic yield in fetuses with ultrasound anomalies and would allow early diagnosis of a genetic disorder irrespective of the (incomplete) fetal phenotype.