Systematic evaluation of genome sequencing for the diagnostic assessment of autism spectrum disorder and fetal structural anomalies.

Short-read genome sequencing (GS) holds the promise of becoming the primary diagnostic approach for the assessment of autism spectrum disorder (ASD) and fetal structural anomalies (FSAs). However, few studies have comprehensively evaluated its performance against current standard-of-care diagnostic tests: karyotype, chromosomal microarray (CMA), and exome sequencing (ES). To assess the clinical utility of GS, we compared its diagnostic yield against these three tests in 1,612 quartet families including an individual with ASD and in 295 prenatal families. Our GS analytic framework identified a diagnostic variant in 7.8% of ASD probands, almost 2-fold more than CMA (4.3%) and 3-fold more than ES (2.7%). However, when we systematically captured copy-number variants (CNVs) from the exome data, the diagnostic yield of ES (7.4%) was brought much closer to, but did not surpass, GS. Similarly, we estimated that GS could achieve an overall diagnostic yield of 46.1% in unselected FSAs, representing a 17.2% increased yield over karyotype, 14.1% over CMA, and 4.1% over ES with CNV calling or 36.1% increase without CNV discovery. Overall, GS provided an added diagnostic yield of 0.4% and 0.8% beyond the combination of all three standard-of-care tests in ASD and FSAs, respectively. This corresponded to nine GS unique diagnostic variants, including sequence variants in exons not captured by ES, structural variants (SVs) inaccessible to existing standard-of-care tests, and SVs where the resolution of GS changed variant classification. Overall, this large-scale evaluation demonstrated that GS significantly outperforms each individual standard-of-care test while also outperforming the combination of all three tests, thus warranting consideration as the first-tier diagnostic approach for the assessment of ASD and FSAs.

The expanded spectrum of human disease associated with GREB1L likely includes complex congenital heart disease.

OBJECTIVE: GREB1L has been linked prenatally to Potter's sequence, as well as less severe anomalies of the kidney, uterus, inner ear, and heart. The full phenotypic spectrum is unknown. The purpose of this study was to characterize known and novel pre- and postnatal phenotypes associated with GREB1L. METHODS: We solicited cases from the Fetal Sequencing Consortium, screened a population-based genomic database, and conducted a comprehensive literature search to identify disease cases associated with GREB1L. We present a detailed phenotypic spectrum and molecular changes. RESULTS: One hundred twenty-seven individuals with 51 unique pathogenic or likely pathogenic GREB1L variants were identified. 24 (47%) variants were associated with isolated kidney anomalies, 19 (37%) with anomalies of multiple systems, including one case of hypoplastic left heart syndrome, five (10%) with isolated sensorineural hearing loss, two (4%) with isolated uterine agenesis; and one (2%) with isolated tetralogy of Fallot. CONCLUSION: GREB1L may cause complex congenital heart disease (CHD) in humans. Clinicians should consider GREB1L testing in the setting of CHD, and cardiac screening in the setting of GREB1L variants.

Monogenic conditions and central nervous system anomalies: A prospective study, systematic review and meta-analysis.

OBJECTIVES: Determine the incremental diagnostic yield of prenatal exome sequencing (pES) over chromosome microarray (CMA) or G-banding karyotype in fetuses with central nervous system (CNS) abnormalities. METHODS: Data were collected via electronic searches from January 2010 to April 2022 in MEDLINE, Cochrane, Web of Science and EMBASE. The NHS England prenatal exome cohort was also included. Incremental yield was calculated as a pooled value using a random-effects model. RESULTS: Thirty studies were included (n = 1583 cases). The incremental yield with pES for any CNS anomaly was 32% [95%CI 27%-36%; I2 = 72%]. Subgroup analysis revealed apparent incremental yields in; (a) isolated CNS anomalies; 27% [95%CI 19%-34%; I2 = 74%]; (b) single CNS anomaly; 16% [95% CI 10%-23%; I2 = 41%]; (c) more than one CNS anomaly; 31% [95% Cl 21%-40%; I2 = 56%]; and (d) the anatomical subtype with the most optimal yield was Type 1 malformation of cortical development, related to abnormal cell proliferation or apoptosis, incorporating microcephalies, megalencephalies and dysplasia; 40% (22%-57%; I2 = 68%). The commonest syndromes in isolated cases were Lissencephaly 3 and X-linked hydrocephalus. CONCLUSIONS: Prenatal exome sequencing provides a high incremental diagnostic yield in fetuses with CNS abnormalities with optimal yields in cases with multiple CNS anomalies, particularly those affecting the midline, posterior fossa and cortex.

Association of deep phenotyping with diagnostic yield of prenatal exome sequencing for fetal brain abnormalities.

PURPOSE: To evaluate whether deep prenatal phenotyping of fetal brain abnormalities (FBAs) increases diagnostic yield of trio-exome sequencing (ES) compared with standard phenotyping. METHODS: Retrospective exploratory analysis of a multicenter prenatal ES study. Participants were eligible if an FBA was diagnosed and subsequently found to have a normal microarray. Deep phenotyping was defined as phenotype based on targeted ultrasound plus prenatal/postnatal magnetic resonance imaging, autopsy, and/or known phenotypes of other affected family members. Standard phenotyping was based on targeted ultrasound alone. FBAs were categorized by major brain findings on prenatal ultrasound. Cases with positive ES results were compared with those that have negative results by available phenotyping, as well as diagnosed FBAs. RESULTS: A total of 76 trios with FBAs were identified, of which 25 (33%) cases had positive ES results and 51 (67%) had negative results. Individual modalities of deep phenotyping were not associated with diagnostic ES results. The most common FBAs identified were posterior fossa anomalies and midline defects. Neural tube defects were significantly associated with receipt of a negative ES result (0% vs 22%, P = .01). CONCLUSION: Deep phenotyping was not associated with increased diagnostic yield of ES for FBA in this small cohort. Neural tube defects were associated with negative ES results.

Diagnosis of TBC1D32-associated conditions: Expanding the phenotypic spectrum of a complex ciliopathy.

Exome sequencing is a powerful tool in prenatal and postnatal genetics and can help identify novel candidate genes critical to human development. We describe seven unpublished probands with rare likely pathogenic variants or variants of uncertain significance that segregate with recessive disease in TBC1D32, including four fetal probands in three unrelated pedigrees and three pediatric probands in unrelated pedigrees. We also report clinical comparisons with seven previously published patients. Index probands were identified through an ongoing prenatal exome sequencing study and through an online data sharing platform (Gene Matcher™). A literature review was also completed. TBC1D32 is involved in the development and function of cilia and is expressed in the developing hypothalamus and pituitary gland. We provide additional data to expand the phenotype correlated with TBC1D32 variants, including a severe prenatal phenotype associated with life-limiting congenital anomalies.

Two unrelated fetuses with ITPR1 missense variants and fetal hydrops.

We describe two fetuses from unrelated families with likely pathogenic variants in ITPR1 that presented with nonimmune fetal hydrops. Trio exome sequencing revealed a de novo heterozygous likely pathogenic missense variant c.7636G > A (p.Val2531Met) in ITPR1 (NM_001378452.1) in proband 1 and a de novo heterozygous likely pathogenic missense variant c.34G > A [p.Gly12Arg] in proband 2. Variants in ITPR1 have been associated with several genetic conditions, including spinocerebellar ataxia 15, spinocerebellar ataxia 29, and Gillespie syndrome. Our report on two patients details a previously undescribed severe fetal presentation of nonimmune hydrops fetalis associated with missense variants in the ITPR1 gene.

Diagnostic yield and psychological outcomes among women pursuing trio-exome sequencing: Do women with recurrent anomalous fetal phenotypes experience more negative psychological outcomes?

PURPOSE: To describe psychological outcomes among people with recurrent anomalous pregnancies pursuing trio-exome sequencing (exome sequencing (ES)) compared to those with one affected. METHODS: We analyzed data from a prospective ES cohort, enrolling patients with major fetal anomaly and normal microarray. Participants completed validated scales before and after ES. We (1) compared responses of those with multiple anomalous pregnancies to those with one affected and (2) conducted linear regression to examine associations between multiple affected pregnancies and post-ES constructs. RESULTS: Of 166 trios, 61 (37%) received results from ES. Forty (24%) had more than one affected pregnancy and 45% of those received a result explaining the fetal phenotype. All participants had clinically significant presequencing generalized psychological distress. For the 93 who completed the post-ES surveys, those with multiple affected pregnancies had higher psychological adaptation scores but worse test related distress scores (9.3 (6.2) versus 7.1(5.6), p = 0.12) and (14.3 (1.5) versus 15.4 (1.4), p = 0.01). In linear regression models, there were no significant differences in post-ES constructs after adjusting for clinically relevant covariates. CONCLUSIONS: All individuals experienced significant generalized psychological distress in the pre-ES period, extending our knowledge of how pregnancy history contributes to parental sequencing outcomes.

Discovering a new part of the phenotypic spectrum of Coffin-Siris syndrome in a fetal cohort.

PURPOSE: Genome-wide sequencing is increasingly being performed during pregnancy to identify the genetic cause of congenital anomalies. The interpretation of prenatally identified variants can be challenging and is hampered by our often limited knowledge of prenatal phenotypes. To better delineate the prenatal phenotype of Coffin-Siris syndrome (CSS), we collected clinical data from patients with a prenatal phenotype and a pathogenic variant in one of the CSS-associated genes. METHODS: Clinical data was collected through an extensive web-based survey. RESULTS: We included 44 patients with a variant in a CSS-associated gene and a prenatal phenotype; 9 of these patients have been reported before. Prenatal anomalies that were frequently observed in our cohort include hydrocephalus, agenesis of the corpus callosum, hypoplastic left heart syndrome, persistent left vena cava, diaphragmatic hernia, renal agenesis, and intrauterine growth restriction. Anal anomalies were frequently identified after birth in patients with ARID1A variants (6/14, 43%). Interestingly, pathogenic ARID1A variants were much more frequently identified in the current prenatal cohort (16/44, 36%) than in postnatal CSS cohorts (5%-9%). CONCLUSION: Our data shed new light on the prenatal phenotype of patients with pathogenic variants in CSS genes.

Parental motivations for and adaptation to trio-exome sequencing in a prospective prenatal testing cohort: Beyond the diagnosis.

PURPOSE: To understand motivations for and parental interpretation of results from trio-exome sequencing (ES) for fetal anomalies with a negative standard genetic diagnosis. METHODS: Analysis of an ongoing, prospective prenatal trio-ES study of pregnancies with ultrasound-identified congenital anomalies and lack of a standard genetic diagnosis. After determination of pregnancy disposition, participants completed questionnaires and a semi-structured interview pre- and post-sequencing. Interviews were analyzed using a constructivist grounded theory methodology to identify themes. Associations between themes and ES result were also examined. RESULTS: One hundred twenty-six trios have been sequenced. Of those, 45 (36%) resulted in fetal diagnosis. One hundred twenty-five women completed pre-sequencing surveys, and 91 women completed post-sequencing surveys. The main themes identified include (1) variable reasons to pursue ES, (2) limited expectations but high hopes from ES, (3) parental adaptation to uncertain results, (4) impact on personal health and reproduction, and (5) gratitude for the process. CONCLUSION: Participants pursued ES for various reasons, most often to identify a diagnosis and guide reproduction. Post-sequencing, most participants described the process, their interpretation of results, and the impact of receiving the results. Less frequently, but of most concern, participants expressed anxiety about testing and implications for themselves, relationships, and other family members, thus identifying an area of high need for additional support among patients undergoing prenatal ES.

Noninvasive prenatal exome sequencing diagnostic utility limited by sequencing depth and fetal fraction.

OBJECTIVE: Sequencing cell-free DNA now allows detection of large chromosomal abnormalities and dominant Mendelian disorders in the prenatal period. Improving upon these methods would allow newborn screening programs to begin with prenatal genetics, ultimately improving the management of rare genetic disorders. METHODS: As a pilot study, we performed exome sequencing on the cell-free DNA from three mothers with singleton pregnancies to assess the viability of broad sequencing modalities in a noninvasive prenatal setting. RESULTS: We found poor resolution of maternal and fetal genotypes due to both sampling and technical issues. CONCLUSION: We find broad sequencing modalities inefficient for noninvasive prenatal applications. Alternatively, we suggest a more targeted path forward for noninvasive prenatal genotyping.

Information is power: The experiences, attitudes and needs of individuals who chose to have prenatal genomic sequencing for fetal anomalies.

OBJECTIVE: This study sought to evaluate the experiences of individuals who chose to participate in a study and receive prenatal genomic sequencing (pGS) for fetuses with congenital structural anomalies. METHOD: Individuals who received research results of prenatal sequencing were invited to participate in semi-structured interviews about their experiences. A constructivist grounded theory approach was used to code and analyze interviews. RESULTS: Thirty-three participants from 27 pregnancies were interviewed. Participants were motivated to enroll in the study to find out more about their fetus' condition and prepare for the future. The waiting period was a time of significant anxiety for participants. Most participants felt relief and closure upon receiving results, regardless of the category of result, and had a clear understanding of the implications of the results. CONCLUSION: Participants' experiences with pGS were often intertwined with the experience of having a fetus with an abnormality. Participants were satisfied with the decision to participate in research and the support they received from the healthcare team, although waiting for results was associated with anxiety. The healthcare team plays an integral role in setting expectations and validating feelings of anxiety, fear and uncertainty.

Prenatal phenotyping of fetal tubulinopathies: A multicenter retrospective case series.

OBJECTIVE: Tubulinopathies refer to conditions caused by genetic variants in isotypes of tubulin resulting in defective neuronal migration. Historically, diagnosis was primarily via postnatal imaging. Our objective was to establish the prenatal phenotype/genotype correlations of tubulinopathies identified by fetal imaging. METHODS: A large, multicenter retrospective case series was performed across nine institutions in the Fetal Sequencing Consortium. Demographics, fetal imaging reports, genetic screening and diagnostic testing results, delivery reports, and neonatal imaging reports were extracted for pregnancies with a confirmed molecular diagnosis of a tubulinopathy. RESULTS: Nineteen pregnancies with a fetal tubulinopathy were identified. The most common prenatal imaging findings were cerebral ventriculomegaly (15/19), cerebellar hypoplasia (13/19), absence of the cavum septum pellucidum (6/19), abnormalities of the corpus callosum (6/19), and microcephaly (3/19). Fetal MRI identified additional central nervous system features that were not appreciated on neurosonogram in eight cases. Single gene variants were reported in TUBA1A (13), TUBB (1), TUBB2A (1), TUBB2B (2), and TUBB3 (2). CONCLUSION: The presence of ventriculomegaly with cerebellar abnormalities in conjunction with additional prenatal neurosonographic findings warrants additional evaluation for a tubulinopathy. Conclusive diagnosis can be achieved by molecular sequencing, which may assist in coordination, prognostication, and reproductive planning.

Impact of prenatal exome sequencing for fetal genetic diagnosis on maternal psychological outcomes and decisional conflict in a prospective cohort.

PURPOSE: To evaluate associations between prenatal trio exome sequencing (trio-ES) and psychological outcomes among women with an anomalous pregnancy. METHODS: Trio-ES study enrolling patients with major fetal anomaly and normal microarray. Women completed self-reported measures and free response interviews at two timepoints: pre- (1) and post- (2) sequencing. Pre-sequencing responses were compared with post-sequencing responses; post-sequencing responses were stratified by women who received trio-ES results that may explain fetal findings, secondary findings (medically actionable or couples with heterozygous variants for the same recessive disorder), or negative results. RESULTS: One hundred fifteen trios were enrolled. Of those, 41/115 (35.7%) received results from trio-ES, including 36 (31.3%) who received results that may explain the fetal phenotype. These women had greater post-sequencing distress compared with women who received negative results, including generalized distress (p = 0.03) and test-related distress (p = 0.2); they also had worse psychological adaptation to results (p = 0.001). Genomic knowledge did not change from pre- to post-sequencing (p = 0.51). CONCLUSION: Women show more distress after receiving trio-ES results compared with those who do not, suggesting that women receiving results may need additional support or counseling to inform current and future reproductive decisions.

Provider Attitudes on Regionalization of Maternity Care: A National Survey.

OBJECTIVES: To explore provider perspectives surrounding national guidelines proposing regionalization of maternal care. METHODS: An 18-item survey focused on provider attitudes and practices surrounding regionalized maternity care was administered to a national sample of practicing obstetricians. We classified respondants reporting less than 500 annual deliveries at their hospital as low-volume providers and those practicing at hospitals performing 500 or more annual deliveries as high-volume providers. We compared responses according to hospital delivery volume using univariate analysis. RESULTS: Of the 497 physicians surveyed, 278 people responded (56%) with 229 currently practicing obstetrics. The median annual delivery volume amongst respondents was 200 (interquartile range 100-1900) with 146 (63.7%) practicing in low-volume delivery centers. The need for medical or surgical expertise was the most commonly reported indication for maternal transfer (19.7%) and independent of practice setting. Ninety-six percent of providers agreed with the concept of regionalization, but respondents in high-volume centers reported higher familiarity with the levels of maternal care paradigm compared to their low-volume counterparts (81.9% v. 62.3%, p < 0.01). Financial factors (60.3%), geography (48.9%), and access to care (43.2%) were the most cited major barriers to regionalization. High-volume providers endorsed geography as a major barrier more often than low-volume providers (57.8% v. 43.8%, p = 0.04). CONCLUSIONS FOR PRACTICE: Obstetricians may agree with the concept of regionalized maternity care but also identify significant barriers to its implementation. Early and frequent engagement of providers reflecting the diversity of delivery centers in a region is a simple but necessary step in any attempts to designate levels of maternal care.

An approach to integrating exome sequencing for fetal structural anomalies into clinical practice.

PURPOSE: We investigated the diagnostic and clinical performance of trio exome sequencing (ES) in parent-fetus trios where the fetus had sonographic abnormalities but normal karyotype, microarray and, in some cases, normal gene-specific sequencing. METHODS: ES was performed from DNA of 102 anomalous fetuses and from peripheral blood from their parents. Parents provided consent for the return of diagnostic results in the fetus, medically actionable findings in the parents, and identification as carrier couple for significant autosomal recessive conditions. RESULTS: In 21/102 (20.6%) fetuses, ES provided a positive-definitive or positive-probable diagnosis. In 10/102 (9.8%), ES provided an inconclusive-possible result. At least 2/102 (2.0%) had a repeat pregnancy during the study period and used the information from the study for prenatal diagnosis in the next pregnancy. Six of 204 (2.9%) parents received medically actionable results that affected their own health and 3/102 (2.9%) of couples received results that they were carriers for the same autosomal recessive condition. CONCLUSION: ES has diagnostic utility in a select population of fetuses where a genetic diagnosis was highly suspected. Challenges related to genetics literacy, variant interpretation, and various types of diagnostic results affecting both fetal and parental health must be addressed by highly tailored pre- and post-test genetic counseling.

Correction: An approach to integrating exome sequencing for fetal structural anomalies into clinical practice.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Providing reproductive health services for women who inject drugs: a pilot program.

BACKGROUND: Needle syringe programs (NSPs), a proven harm reduction strategy for people who inject drugs, frequently offer limited healthcare services for their clients. Women who inject drugs face multiple barriers to accessing reproductive health care in traditional settings: personal histories of trauma, judgmental treatment from providers, and competing demands on their time. Our aim was to implement patient-centered reproductive healthcare services at a Seattle NSP. METHODS: We interviewed clients and staff of an NSP in Seattle and staff of other community-based organizations serving women who inject drugs, then used the Consolidated Framework for Implementation Research to code transcripts deductively. Based on our qualitative work, we implemented reproductive health care at the NSP program 1 day per week. We evaluated the implementation by surveying staff and clients and auditing charts over a 9-month period. RESULTS: Clients and staff (N = 15 for clients, N = 13 for staff) noted a high unmet need for trauma-informed, accessible reproductive health care. We successfully implemented reproductive health care services including short- and long-acting contraception, sexually transmitted disease testing, and cervical cancer screening. Survey data was limited but demonstrated client satisfaction with services. CONCLUSIONS: Integrating reproductive health care into an NSP's clinical services is feasible and can be a source of low-barrier preventive care for women unable to seek gynecologic care elsewhere.

Use of a novel computerized decision aid for aneuploidy screening: a randomized controlled trial.

PURPOSE: To assess whether knowledge following use of a decision aid (DA) for aneuploidy screening and testing is inferior to knowledge in women who saw a genetic counselor (GC) only. METHODS: This is a randomized controlled noninferiority trial of pregnant women at ≤22 weeks. Women who were scheduled for GC were randomly allocated to use a DA before GC or to GC alone. The primary outcome was knowledge score, comparing women who had used the DA only to those who saw GC alone. Analysis was by intent to treat. RESULTS: Between January and October 2017, 197 women were randomized, 105 to GC only and 92 to DA use before GC. Demographics and baseline knowledge were similar between groups. Mean knowledge score following DA use was not inferior to mean knowledge score following GC only (10.4 vs. 10.6, p = 0.306). Decisional conflict was similar following completion of the DA to following GC only, but was reduced following completion of both the DA and GC compared with GC only (0.22 vs. 1.74, p = 0.003). CONCLUSION: Knowledge surrounding aneuploidy screening in women who used a DA was not inferior to knowledge in women who underwent GC. Use of the DA in addition to GC reduced decisional conflict.

Ethical and counseling challenges in prenatal exome sequencing.

OBJECTIVE: Ethical and counseling challenges are expected with the introduction of prenatal whole exome sequencing. In this study, we describe specific challenges identified through the UNC-Chapel Hill Prenatal Exome Sequencing Study. METHODS: Participants were a subset of women participating in the fetal exome study, which has enrolled 73 mother-father-fetus trios in pregnancies diagnosed with structural anomalies and normal standard genetic testing results. In this descriptive study, cases were reviewed by members of the research team, including a bioethicist, to identify counseling challenges. Illustrative cases were chosen by group consensus. RESULTS: Four illustrative cases were identified for further analysis. Challenges included need for adequate counseling and informed consent, challenges in prenatal variant interpretation, performing prenatal diagnosis in subsequent pregnancies, inability to identify a genetic etiology, and identifying parental secondary findings. CONCLUSION: Our study illustrates several challenges identified in an ongoing prenatal exome study. While genomic medicine is a powerful tool for prenatal diagnosis, it is important that clinicians understand the ethical implications and parental perceptions of this testing modality.