Limits to the scope of non-invasive prenatal testing (NIPT): an analysis of the international ethical framework for prenatal screening and an interview study with Dutch professionals.

BACKGROUND: The introduction of non-invasive prenatal testing (NIPT) for foetal aneuploidies is currently changing the field of prenatal screening in many countries. As it is non-invasive, safe and accurate, this technique allows for a broad implementation of first-trimester prenatal screening, which raises ethical issues, related, for instance, to informed choice and adverse societal consequences. This article offers an account of a leading international ethical framework for prenatal screening, examines how this framework is used by professionals working in the field of NIPT, and presents ethical guidance for the expansion of the scope of prenatal screening in practice. METHODS: A comparative analysis of authoritative documents is combined with 15 semi-structured interviews with professionals in the field of prenatal screening in the Netherlands. Data were recorded, transcribed verbatim and analysed using thematic analysis. RESULTS: The current ethical framework consists of four pillars: the aim of screening, the proportionality of the test, justice, and societal aspects. Respondents recognised and supported this framework in practice, but expressed some concerns. Professionals felt that pregnant women do not always make informed choices, while this is seen as central to reproductive autonomy (the aim of screening), and that pre-test counselling practices stand in need of improvement. Respondents believed that the benefits of NIPT, and of an expansion of its scope, outweigh the harms (proportionality), which are thought to be acceptable. They felt that the out-of-pocket financial contribution currently required by pregnant women constitutes a barrier to access to NIPT, which disproportionally affects those of a lower socioeconomic status (justice). Finally, professionals recognised but did not share concerns about a rising pressure to test or discrimination of disabled persons (societal aspects). CONCLUSIONS: Four types of limits to the scope of NIPT are proposed: NIPT should generate only test outcomes that are relevant to reproductive decision-making, informed choice should be (made) possible through adequate pre-test counselling, the rights of future children should be respected, and equal access should be guaranteed. Although the focus of the interview study is on the Dutch healthcare setting, insights and conclusions can be applied internationally and to other healthcare systems.

Choosing between Higher and Lower Resolution Microarrays: do Pregnant Women Have Sufficient Knowledge to Make Informed Choices Consistent with their Attitude?

Developments in prenatal testing allow the detection of more findings. SNP arrays in prenatal diagnosis (PND) can be analyzed at 0.5 Mb resolution detecting more clinically relevant anomalies, or at 5 Mb resolution. We investigated whether women had sufficient knowledge to make informed choices regarding the scope of their prenatal test that were consistent with their attitude. Pregnant women could choose between testing at 5 or at 0.5 Mb array. Consenting women (N = 69) received pre-test genetic counseling by phone and filled out the Measure of Informed Choice questionnaire designed for this study. Choices based on sufficient knowledge and consistent with attitude were considered informed. Sixty-two percent of the women made an adequately informed choice, based on sufficient knowledge and attitude-consistent with their choice of microarray resolution. Women who made an informed choice, opted for 0.5 Mb array resolution more often. There were no differences between women making adequately informed or less informed choices regarding level of experienced anxiety or doubts. Over time on T0 and T1, anxiety and doubts significantly decreased. While previous studies demonstrated that knowledge is an important component in informed decision-making, this study underlines that a consistent attitude might be equally important for decision-making. We advocate more focus on attitude-consistency and deliberation as compared to only a strong focus on knowledge.

Prenatal and postnatal findings in small-for-gestational-age fetuses without structural ultrasound anomalies at 18-24 weeks.

OBJECTIVE: To assess phenotypic and genotypic characteristics of small-for-gestational-age (SGA) fetuses without structural anomalies at 18-24 weeks' gestation. METHODS: This retrospective study included structurally normal singleton fetuses with an abdominal circumference ≤ 5th percentile on detailed ultrasound examination between 18 and 24 weeks' gestation. Cases were stratified according to the absence or presence of other abnormal ultrasound findings, such as abnormal amniotic fluid or soft markers. All patients were offered invasive prenatal testing with rapid aneuploidy detection by qualitative fluorescence polymerase chain reaction (QF-PCR) and, if normal, consecutive single nucleotide polymorphism (SNP) array was also offered. Detailed postnatal follow-up (≥ 5 months) was performed. In cases in which a syndromic phenotype became apparent within 5 months after birth and SNP array had not been performed prenatally, it was performed postnatally. RESULTS: A total of 211 pregnancies were eligible for inclusion. Of the 158 cases with isolated SGA on ultrasound, 36 opted for invasive prenatal testing. One case of trisomy 21 and one case of a submicroscopic abnormality (a susceptibility locus for neurodevelopmental disease) were detected. Postnatal follow-up showed a postnatal apparent syndromic phenotype in 10 cases. In one case this was due to trisomy 21 and the other nine (5.8%; 95% CI, 2.8-10.0%) cases had normal SNP array results. In 32/53 cases with SGA and associated ultrasound abnormalities, parents opted for invasive testing. One case of trisomy 21 and one of triploidy were found. In 11 cases a syndromic phenotype became apparent after birth. One was due to trisomy 21 and in one case a submicroscopic anomaly (a susceptibility locus) was found. The remaining syndromic cases (17.3%; 95% CI, 8.7-29.0%) had normal SNP array results. CONCLUSION: Testing for chromosomal anomalies should be offered in cases of SGA between 18 and 24 weeks' gestation. Whole chromosome anomalies occur in 1.3% (95% CI, 0.2-3.9%) of isolated SGA and 5.8% (95% CI, 1.5-14.0%) of associated SGA. In 0.6% (95% CI, 0.1-2.8%) and 1.9% (95% CI, 0.2-8.2%), respectively, SNP array detected a susceptibility locus for neurodevelopmental disease that would not be detected by karyotyping, QF-PCR or non-invasive prenatal testing. Therefore, and because the genetic causes of SGA are diverse, we suggest SNP array testing in cases of SGA. Thorough postnatal examination and follow-up of infants that presented with reduced fetal growth is important because chromosomally normal syndromic phenotypes occur frequently in SGA fetuses. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Advanced genomic testing may aid in counseling of isolated agenesis of the corpus callosum on prenatal ultrasound.

OBJECTIVE: Isolated agenesis of the corpus callosum on fetal ultrasound has a varied prognosis. Microarray and exome sequencing (ES) might aid in prenatal counseling. METHOD: This study includes 25 fetuses with apparently isolated complete corpus callosum (cACC) on ultrasound. All cases were offered single nucleotide polymorphism array. Complementary ES was offered postnatally in selected cases. Clinical physical and neurodevelopmental follow-up was collected. RESULTS: Eighteen cases opted for single nucleotide polymorphism array testing, which detected a causal anomaly in 2/18 (11.1%; 95% CI 2.0%-31%). Among ongoing pregnancies without a causal anomaly on microarray, 30% (95% CI 8.5%-60%) showed intellectual disability. Postnatal magnetic resonance imaging and physical examination often (64%; 95% CI 38%-85%, and 64%; 95% CI 38%-85%, respectively) revealed additional physical anomalies in cases without a causal anomaly on microarray. Two cases appeared truly isolated after birth. Postnatal sequencing in 4 of 16 cases without a causal anomaly on microarray but with intellectual disability and/or additional postnatal physical anomalies revealed 2 single-gene disorders. Therefore, the estimated diagnostic yield of ES in chromosomally normal cACC fetuses is between 2/4 (50%; 95% CI 11%-89%) and 2/16 (13.3%; 95% CI 2.4%-36%). CONCLUSION: In accordance with current guidelines, we conclude that microarray should be offered in case of isolated cACC on ultrasound. ES is likely to be informative for prenatal counseling and should be offered if microarray is normal.

The Psychological Impact of Prenatal Diagnosis and Disclosure of Susceptibility Loci: First Impressions of Parents' Experiences.

Genomic microarray may detect susceptibility loci (SL) for neurodevelopmental disorders such as autism and epilepsy, with a yet unquantifiable risk for the fetus. The prenatal disclosure of susceptibility loci is a topic of much debate. Many health care professionals fear that reporting susceptibility loci may put a psychological burden on pregnant couples. It is our policy to disclose prenatal susceptibility loci as we recognize them as actionable for prospective parents. The aim of this report was to evaluate the psychological impact of disclosing a prenatal diagnosis of susceptibility loci. The psychological impact of disclosing susceptibility loci was evaluated in the first patients who received such results. Eight out of 15 women who had a susceptibility locus disclosed and four of their partners consented to share their experiences through a telephonic evaluation (n = 12). Follow-up time ranged from 3 to 15 months after their prenatal test result. The reporting of susceptibility loci was initially 'shocking' for five parents while the other seven felt 'worried'. Ten out of 12 participants indicated they would like to be informed about the susceptibility locus again, two were unsure. Most had no enduring worries. Participants unanimously indicated that pregnant couples should have an individualized pre-test choice about susceptibility loci (non)disclosure. We observed no negative psychological impact with the prenatal diagnosis and disclosure of SL on participants. A key factor in mitigating parental anxiety with SL disclosure appears to be post-test genetic counseling. Our report confirms that pregnant women and their partners prefer an individualized choice regarding the scope of prenatal testing.

Pregnant couples at increased risk for common aneuploidies choose maximal information from invasive genetic testing.

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.

Additional value of prenatal genomic array testing in fetuses with isolated structural ultrasound abnormalities and a normal karyotype: a systematic review of the literature.

OBJECTIVE: To establish the prevalence of submicroscopic genetic copy number variants (CNVs) in fetuses with a structural ultrasound anomaly (restricted to one anatomical system) and a normal karyotype. The aim was to determine the diagnostic and prognostic value of genomic array testing in these pregnancies. METHODS: Embase and PubMed databases were systematically searched for all relevant articles on prevalence of pathogenic submicroscopic CNVs in fetuses with ultrasound anomalies. Reported cases were sorted into groups according to anatomical site of the detected ultrasound anomaly. The prevalence of causative submicroscopic CNVs was calculated for each group. RESULTS: Combined data of the reviewed studies (n = 18) indicated that fetuses with an ultrasound anomaly restricted to one anatomical system (n = 2220) had a 3.1-7.9% chance of carrying a causative submicroscopic CNV, depending on the anatomical system affected. This chance increased to 9.1% for fetuses with multiple ultrasound anomalies (n = 1139). CONCLUSION: This review indicates that 3.1-7.9% of fetuses with a structural ultrasound anomaly restricted to one anatomical system and a normal karyotype will show a submicroscopic CNV, which explains its phenotype and provides information for fetal prognosis. Therefore, we conclude that microarray has considerable diagnostic and prognostic value in these pregnancies.

De novo truncating mutations in E6-AP ubiquitin-protein ligase gene (UBE3A) in Angelman syndrome.

Angelman syndrome (AS) is associated with maternal deletions of human chromosome 15q11-q13 and with paternal uniparental disomy for this region indicating that deficiency of an imprinted, maternally expressed gene within the critical interval is the likely cause of the syndrome. Although the gene for E6-AP ubiquitin-protein ligase (UBE3A) was mapped to the critical region for AS, evidence of expression from both parental alleles initially suggested that it was an unlikely candidate gene for this disorder. Because attempts to identify any novel maternally expressed transcripts were unsuccessful and because the UBE3A gene remained within a narrowed AS critical region, we searched for mutations in UBE3A in 11 AS patients without known molecular defects (large deletion, uniparental disomy, or imprinting mutation). This analysis tested the possibility that deficiency of an undefined, maternally expressed transcript or isoform of the UBE3A gene could cause AS. Four mutations were identified including a de novo frameshift mutation and a de novo nonsense mutation in exon 3 and two missense mutations of less certain significance. The de novo truncating mutations indicate that UBE3A is the AS gene and suggest the possibility of a maternally expressed gene product in addition to the biallelically expressed transcript. Intragenic mutation of UBE3A in AS is the first example of a genetic disorder of the ubiquitin-dependent proteolytic pathway in mammals. It may represent an example of a human genetic disorder associated with a locus producing functionally distinct imprinted and biallelically expressed gene products.

XCI in preimplantation mouse and human embryos: first there is remodelling .

Female eutherians silence one of their X chromosomes to accomplish an equal dose of X-linked gene expression compared with males. The mouse is the most widely used animal model in XCI research and has proven to be of great significance for understanding the complex mechanism of X-linked dosage compensation. Although the basic principles of XCI are similar in mouse and humans, differences exist in the timing of XCI initiation, the genetic elements involved in XCI regulation and the form of XCI in specific tissues. Therefore, the mouse has its limitations as a model to understand early human XCI and analysis of human tissues is required. In this review, we describe these differences with respect to initiation of XCI in human and mouse preimplantation embryos, the extra-embryonic tissues and the in vitro model of the epiblast: the embryonic stem cells.

Defective deacetylation of histone 4 K12 in human oocytes is associated with advanced maternal age and chromosome misalignment.

BACKGROUND: Chromosome segregation errors during human oocyte meiosis are associated with low fertility in humans and the incidence of these errors increases with advancing maternal age. Studies of mitosis and meiosis suggest that defective remodeling of chromatin plays a causative role in aneuploidy. We analyzed the histone deacetylation pattern during the final stages of human oocyte maturation to investigate whether defective epigenetic regulation of chromatin remodeling in human oocytes is related to maternal age and leads to segregation errors. METHODS: Human surplus oocytes of different meiotic maturation stages [germinal vesicle (GV), metaphase (M)I and MII] were collected from standard IVF/ICSI treatments. Oocytes were analyzed for acetylation of different lysines of histone 4 (H4K5, H4K8, H4K12 and H4K16) and for α-tubulin. RESULTS: Human GV oocytes had an intense staining of the chromatin for all four histone 4 lysine acetylations. MI and MII stage oocytes showed either normal deacetylation or various amounts of defective histone deacetylation. Residual H4K12 acetylation was more frequently found in oocytes obtained from older women, with a significant correlation between defective deacetylation and maternal age (r = 0.185, P = 0.007). Eighty-eight percent of the oocytes with residual acetylation had misaligned chromosomes, whereas only 33% of the oocytes that showed correct deacetylated chromatin had misaligned chromosomes (P < 0.001). CONCLUSIONS: We conclude that defective deacetylation during human female meiosis increases with maternal age and is correlated with misaligned chromosomes. As chromosome misalignment predisposes to segregation errors, our data imply that defective regulation of histone deacetylation could be an important factor in age-related aneuploidy.

Omphalocele: comparison of outcome following prenatal or postnatal diagnosis.

OBJECTIVES: To assess the impact of prenatal compared with postnatal diagnosis on outcome for liveborn infants with an isolated or with a non-isolated omphalocele. METHODS: This was a retrospective analysis of 101 prenatally and 45 postnatally diagnosed cases of omphalocele. Cases were collected from the ultrasound database of the Division of Obstetrics and Prenatal Medicine and the patient database of the Department of Pediatric Surgery. RESULTS: Following confirmation at delivery or autopsy, prenatally diagnosed omphaloceles included 21 isolated cases, 44 non-isolated cases with a normal karyotype and 36 non-isolated cases with an abnormal karyotype. Of the prenatally diagnosed apparently isolated cases (n = 31), 12 (39%; 95% CI, 22-58%) revealed associated anomalies after delivery. Liveborn infants with an isolated omphalocele had significantly worse short-term morbidity following prenatal diagnosis (n = 14) compared with diagnosis at birth (n = 29), having a lower gestational age at delivery, lower Apgar scores, longer duration of ventilation and parenteral nutrition, more readmissions and a longer hospital stay. The prenatally diagnosed subset contained more infants with a giant omphalocele (9/14 vs. 3/29, P = 0.001) and liver herniation (8/14 vs. 6/29, P = 0.02). The outcome of liveborn infants with a non-isolated omphalocele diagnosed prenatally (n = 17) was not different from that of those diagnosed at birth (n = 16), except for a greater need for ventilation and parenteral nutrition in the prenatal subset. CONCLUSION: When counseling patients with a prenatal diagnosis of isolated omphalocele, it is important to remember that over one third could turn out to have associated anomalies. Liveborn infants with an isolated omphalocele detected prenatally have worse short-term morbidity than do cases detected at birth. Those with non-isolated omphaloceles detected prenatally have an increased need for ventilation and parenteral nutrition compared with those detected at birth.

X-linked recessive inheritance of radial ray deficiencies in a family with four affected males.

Radial ray deficiencies are frequently associated with additional clinical anomalies and have a heterogeneous aetiology. X-linked forms are extremely rare. We report a family in which four male relatives show bilateral absence of the radius with presence of the thumbs and associated anomalies. The segregation of the phenotype is suggestive for X-linked recessive inheritance. This is confirmed by performing linkage analysis using 24 markers spanning the X chromosome in which a maximum lod score of 1.93 for DXS8067 and DXS1001 is obtained. We defined a critical region of maximal 16.2 cM on the X chromosome with haplotype analysis.

Differences in complexity of isolated brachydactyly type C cannot be attributed to locus heterogeneity alone.

Hereditary isolated brachydactyly type C (OMIM 113100) mostly follows an autosomal dominant pattern of inheritance with a marked variability in expression. This phenotype has been mapped to two different loci on chromosomes 12q24 and 20q11.2. The latter locus contains the cartilage-derived morphogenetic protein (CDMP)1 gene, in which a null mutation has been found in patients with malformations restricted to the upper limbs. A more complex brachydactyly type C phenotype has been mapped to chromosome 12q24. Differences in complexity of these phenotypes have been attributed to locus heterogeneity. Clinical subclassification based on the degree of complexity of the phenotype has therefore been suggested. We present patients with a complex brachydactyly type C phenotype in whom there is considerable intra- and interfamilial variability in expression. We show that clinical subclassification based on the complexity of the brachydactyly type C phenotype related to the genetic defect is not feasible. We present evidence that differences in complexity are not only due to locus heterogeneity, but that genetic modifiers and/or environmental factors must also play a role.

Lymphangiectasia with persistent Müllerian derivatives: confirmation of autosomal recessive Urioste syndrome.

We report on a sibship with protein-losing enteropathy related to intestinal lymphangiectasia, a peculiar face, and genital anomalies. The parents are distantly related and from Dutch ancestry. The first patient was born with a protein-losing enteropathy, craniofacial anomalies, and renal defects. At 1 year of age, she died of severe complications of the protein-losing enteropathy and respiratory distress. Her brother was a cytogenetically normal male fetus identified by prenatal ultrasound at 19 weeks with similar anomalies. The pregnancy was terminated at 20 weeks. Autopsy showed müllerian duct remnants. These cases seem to confirm the Urioste syndrome [Urioste et al., 1993: Am J Med Genet 47:494-503]. Although it was previously only reported in 46,XY individuals, this report of a consanguineous family with an affected sibship of both sexes suggests it to be an autosomal recessive entity.

[Prenatal investigations for Down's syndrome: medical-technical considerations and dilemmas arising from current screening methods]. / Prenataal onderzoek naar downsyndroom: medisch-technische overwegingen en dilemma's voortkomend uit de huidige toepassingsmogelijkheden.

Prenatal investigations can be divided into specific diagnostic investigations i.e. chorionic villus sampling, amniocentesis and selective ultrasonography for the detection of fetal abnormality, and screening tests which estimate the chances of the condition being present. These include routine ultrasonography and tests based on biochemical and echoscopic markers. Amniocentesis is the most reliable test to detect chromosomal anomalies, but is associated with a low risk of miscarriage and the results are known only relatively late in pregnancy. Implementing the prenatal screening tests will enable the better identification of those women with an increased risk of chromosomal anomalies, and consequently to fewer invasive diagnostic procedures. The choice whether to have prenatal screening should always be made by the parents after they have been told of the advantages and disadvantages of these investigations.

Prenatal detection and outcome of congenital diaphragmatic hernia (CDH) associated with deletion of chromosome 15q26: two patients and review of the literature.

Congenital diaphragmatic hernia (CDH) is a severe birth defect characterized by a defect in the diaphragm with pulmonary hypoplasia and postnatal pulmonary hypertension. Approximately 50% of CDH cases are associated with other non-pulmonary congenital anomalies (so called non-isolated CDH) and in 5-10% of cases there is a chromosomal etiology. The majority of CDH cases are detected prenatally. In some cases prenatal chromosome analysis reveals a causative chromosomal anomaly, most often aneuploidy. Deletion of 15q26 is the most frequently described structural chromosomal aberration in patients with non-isolated CDH. In this paper we report on two patients with a deletion of 15q26 and phenotypes similar to other patients with CDH caused by 15q26 deletions. This phenotype consists of intra-uterine growth retardation, left-sided CDH, cardiac anomalies and characteristic facial features, similar to those seen in Fryns syndrome. We propose that when this combination of birth defects is identified, either pre- or postnatally, further investigations to confirm or exclude a deletion of 15q26 are indicated, since the diagnosis of this deletion will have major consequences for the prognosis and, therefore, can affect decision making.