Optimizing prenatal diagnosis and referral of classic bladder exstrophy: Lessons from a single-institution experience.

INTRODUCTION: Classic bladder exstrophy (CBE) is a malformation of the genitourinary system that occurs due to failure of abdominal wall closure. Unlike other malformations of similar incidence, prenatal diagnosis of CBE relies on suggested, rather than formal, diagnostic criteria. OBJECTIVE: This report describes prenatal diagnosis of CBE in the largest single-institutional cohort to date and delineates key sonographic findings and protocols for specialist referral. MATERIALS AND METHODS: A single-institutional database was reviewed for CBE patients born since 2000. Data on screening ultrasound use, gestational age at ultrasound, and abnormal findings were extracted. Where possible, time of prenatal diagnosis (pre- or postnatal and gestational age), ultrasound findings and other imaging data, specialist referral, institution of birth and closure, and outcome of primary closure attempt were compared. RESULTS: Of 557 patients born with CBE between 2000 and 2022, 284 met inclusion criteria and complete data were available for 280 (229 born domestically and 51 born internationally) who were included for analysis. Abnormal sonography suggestive of CBE was present for 48% (n = 134) of patients, for whom absent bladder was the most common abnormal finding (76% [102/134]). Of domestic patients, 46% (n = 106) were diagnosed prenatally at a median gestational age of 22 weeks (inter-quartile range [IQR]: 20-24), and 14% (n = 32) underwent confirmatory fetal magnetic resonance imaging. Of domestic patients with abnormal prenatal findings, 75% (n = 80/106) consulted with maternal-fetal medicine and 58% (n = 62/106) consulted with pediatric urology. On univariate analysis, prenatal diagnosis was positively associated with primary repair at Association for the Bladder Exstrophy Community-recognized centers of excellence (54% vs. 38%, p = 0.02) and negatively associated with osteotomy at primary closure (41% vs 59%, p = 0.003) but not success of primary closure (74% vs. 82%, p = 0.07). DISCUSSION: Rates of prenatal diagnosis in this cohort were similar to previous reports of smaller cohorts. Diagnosis allows for comprehensive pre- and postnatal follow-up with a pediatric urologist, with implications on birth planning and decisions on termination of pregnancy. Because of the previously-reported association between exstrophy and in vitro fertilization, these pregnancies should undergo detailed sonography. Any nonvisualization of the fetal bladder should prompt a detailed exam, and any finding characteristic of bladder exstrophy warrants referral to pediatric urology. CONCLUSIONS: Although CBE is a rare disorder, it is underdiagnosed during pregnancy. Sonographers and obstetricians should be aware of characteristic findings and best practices following diagnosis. Early referral to pediatric urology and maternal-fetal medicine is important for counseling and postnatal planning.

Prenatal Diagnosis of Fetal Aqueductal Stenosis: A Multicenter Prospective Observational Study through the North American Fetal Therapy Network (NAFTNet).

INTRODUCTION: A critical component of an evidence-based reassessment of in-utero intervention for fetal aqueductal stenosis (fetal AS) is determining if the prenatal diagnosis can be accurately made at a gestational age amenable to in-utero intervention. METHODS: A multicenter, prospective, observational study was conducted through the North American Fetal Therapy Network (NAFTNet). Pregnancies complicated by severe CNS ventriculomegaly (lateral ventricle diameter >15 mm) not secondary to a primary diagnosis (myelomeningocele, encephalocele, etc.) were recruited at diagnosis. Imaging and laboratory findings were recorded in an online REDCap database. After evaluation, investigators were asked to render their degree of confidence in the diagnosis of fetal AS. The prenatal diagnosis was compared to the postnatal diagnosis obtained through neonatal neuroimaging. Performance characteristics of ultrasound and MRI were calculated, as was the mean gestational age at diagnosis. RESULTS: Between April 2015 and October 2022, eleven NAFTNet centers contributed 64 subjects with severe fetal CNS ventriculomegaly. Of these, 56 had both prenatal and postnatal diagnoses recorded. Ultrasound revealed 32 fetal AS true positives, 4 false positives, 7 false negatives, and 13 true negatives rendering a sensitivity of 0.82, a specificity of 0.76, a positive predictive value of 0.89, and a negative predictive value of 0.65. The mean gestational age at diagnosis by ultrasound was 25.5 weeks (std +/- 4.7w). The proportion of agreement (true positive + true negative/n) was highest at 24 weeks gestation. For fetal MRI (n=35), the sensitivity for fetal AS was 0.95, specificity was 0.69, positive predictive value was 0.84, and negative predictive value was 0.90. MRI was performed at 25 weeks on average. CONCLUSION: The prenatal diagnosis of fetal aqueductal stenosis can be made with accuracy at a gestational age potentially amenable to in-utero intervention. Only 7% of subjects were incorrectly diagnosed prenatally with fetal AS by ultrasound and 11% by MRI. Diagnostic accuracy of fetal AS will likely improve with increased experience.

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.

The genetic etiologies of bilateral renal agenesis.

OBJECTIVE: The goal of this study was to review and analyze the medical literature for cases of prenatal and/or postnatally diagnosed bilateral renal agenesis (BRA) and create a comprehensive summary of the genetic etiologies known to be associated with this condition. METHODS: A literature search was conducted as a scoping review employing Online Mendeliain Inheritance in Man, PubMed, and Cochrane to identify cases of BRA with known underlying genetic (chromosomal vs. single gene) etiologies and those described in syndromes without any known genetic etiology. The cases were further categorized as isolated versus non-isolated, describing additional findings reported prenatally, postnatally, and postmortem. Inheritance pattern was also documented when appropriate in addition to the reported timing of diagnosis and sex. RESULTS: We identified six cytogenetic abnormalities and 21 genes responsible for 20 single gene disorders associated with BRA. Five genes have been reported to associate with BRA without other renal anomalies; sixteen others associate with both BRA as well as unilateral renal agenesis. Six clinically recognized syndromes/associations were identified with an unknown underlying genetic etiology. Genetic etiologies of BRA are often phenotypically expressed as other urogenital anomalies as well as complex multi-system syndromes. CONCLUSION: Multiple genetic etiologies of BRA have been described, including cytogenetic abnormalities and monogenic syndromes. The current era of the utilization of exome and genome-wide sequencing is likely to significantly expand our understanding of the underlying genetic architecture of BRA.

De novo variants identified by trio whole exome sequencing of bladder exstrophy epispadias complex.

Bladder exstrophy epispadias complex (BEEC) encompasses a spectrum of conditions ranging from mild epispadias to the most severe form: omphalocele-bladder exstrophy-imperforate anus-spinal defects (OEIS). BEEC involves abnormalities related to anatomical structures that are proposed to have a similar underlying etiology and pathogenesis. In general, BEEC, is considered to arise from a sequence of events in embryonic development and is believed to be a multi-etiological disease with contributions from genetic and environmental factors. Several genes have been implicated and mouse models have been generated, including a knockout model of p63, which is involved in the synthesis of stratified epithelium. Mice lacking p63 have undifferentiated ventral urothelium. MNX1 has also been implicated. In addition, cigarette smoking, diazepam and clomid have been implied as environmental factors due to their relative association. By in large, the etiology and pathogenesis of human BEEC is unknown. We performed de novo analysis of whole exome sequencing (WES) of germline samples from 31 unrelated trios where the probands have a diagnosis of BEEC syndrome. We also evaluated the DECIPHER database to identify copy number variants (CNVs) in genes in individuals with the search terms "bladder exstrophy" in an attempt to identify additional candidate genes within these regions. Several de novo variants were identified; however, a candidate gene is still unclear. This data further supports the multi-etiological nature of BEEC.

The utility of gene sequencing in identifying an underlying genetic disorder in prenatally suspected lower urinary tract obstruction.

OBJECTIVE: Fetal megacystis generally presents as suspected lower urinary tract obstruction (LUTO), which is associated with severe perinatal morbidity. Genetic etiologies underlying LUTO or a LUTO-like initial presentation are poorly understood. Our objectives are to describe single gene etiologies in fetuses initially ascertained to have suspected LUTO and to elucidate genotype-phenotype correlations. METHODS: A retrospective case series of suspected fetal LUTO positive for a molecular diagnosis was collected from five centers in the Fetal Sequencing Consortium. Demographics, sonograms, genetic testing including variant classification, and delivery outcomes were abstracted. RESULTS: Seven cases of initially prenatally suspected LUTO-positive for a molecular diagnosis were identified. In no case was the final diagnosis established as urethral obstruction that is, LUTO. All variants were classified as likely pathogenic or pathogenic. Smooth muscle deficiencies involving the bladder wall and interfering with bladder emptying were identified in five cases: MYOCD (2), ACTG2 (2), and MYH11 (1). Other genitourinary and/or non-genitourinary malformations were seen in two cases involving KMT2D (1) and BBS10 (1). CONCLUSION: Our series illustrates the value of molecular diagnostics in the workup of fetuses who present with prenatally suspected LUTO but who may have a non-LUTO explanation for their prenatal ultrasound findings.

Associations of Preconception Body Weight, Body Mass Index, and Hypertension with Preeclampsia.

Objective: Maximizing preconception health is an important strategy to prevent preeclampsia in pregnancy. Preeclampsia remains a significant cause of maternal and fetal morbidity and mortality. We examined the associations between preconception maternal body weight, body mass index (BMI), and blood pressure with preeclampsia and its related outcomes. Materials and Methods: We performed a retrospective review of 11,214 live births from 6 months preconception during 2009-2018 in the University of Washington medical system. Outcomes were analyzed using chi-square, analysis of variance, and t-tests. Binary logistic regression was performed to examine associations. Results: Of 11,214 births, 1,539 (13.7%) were complicated by preeclampsia. Individuals with preeclampsia weighed more and had higher blood pressure from 6 months preconception to at least 6 months of pregnancy compared with those without preeclampsia (p < 0.001). Persons with prepregnancy systolic blood pressure (SBP) ≥130 mmHg were 3.2 times more likely to develop preeclampsia than those with SBP <130 mmHg (adjusted odds ratio [aOR] = 3.24, 95% confidence interval [CI] = 2.37-4.43). Women with prepregnancy BMI ≥30 kg/m2 were 2.3 times more likely to develop preeclampsia (aOR = 2.31, 95% CI = 1.72-3.10) than those with BMI <30 kg/m2. Mothers with preeclampsia were more likely to deliver preterm (29% vs. 13.8%, p < 0.001) and have neonates with 5-minute Apgar scores <8 (22.1% vs. 12.1%, p = 0.02) and lower preterm birthweights (1,909 g, 95% CI = 1,813-2,004 g vs. 2,057 g, 95% CI = 1,989-2,123 g). Conclusions: Maternal obesity and elevated blood pressure from 6 months preconception to 6 months of pregnancy were associated with preeclampsia, resulting in maternal and fetal complications.

Neonatal Survival After Serial Amnioinfusions for Bilateral Renal Agenesis: The Renal Anhydramnios Fetal Therapy Trial.

Importance: Early anhydramnios during pregnancy, resulting from fetal bilateral renal agenesis, causes lethal pulmonary hypoplasia in neonates. Restoring amniotic fluid via serial amnioinfusions may promote lung development, enabling survival. Objective: To assess neonatal outcomes of serial amnioinfusions initiated before 26 weeks' gestation to mitigate lethal pulmonary hypoplasia. Design, Setting, and Participants: Prospective, nonrandomized clinical trial conducted at 9 US fetal therapy centers between December 2018 and July 2022. Outcomes are reported for 21 maternal-fetal pairs with confirmed anhydramnios due to isolated fetal bilateral renal agenesis without other identified congenital anomalies. Exposure: Enrolled participants initiated ultrasound-guided percutaneous amnioinfusions of isotonic fluid before 26 weeks' gestation, with frequency of infusions individualized to maintain normal amniotic fluid levels for gestational age. Main Outcomes and Measures: The primary end point was postnatal infant survival to 14 days of life or longer with dialysis access placement. Results: The trial was stopped early based on an interim analysis of 18 maternal-fetal pairs given concern about neonatal morbidity and mortality beyond the primary end point despite demonstration of the efficacy of the intervention. There were 17 live births (94%), with a median gestational age at delivery of 32 weeks, 4 days (IQR, 32-34 weeks). All participants delivered prior to 37 weeks' gestation. The primary outcome was achieved in 14 (82%) of 17 live-born infants (95% CI, 44%-99%). Factors associated with survival to the primary outcome included a higher number of amnioinfusions (P = .01), gestational age greater than 32 weeks (P = .005), and higher birth weight (P = .03). Only 6 (35%) of the 17 neonates born alive survived to hospital discharge while receiving peritoneal dialysis at a median age of 24 weeks of life (range, 12-32 weeks). Conclusions and Relevance: Serial amnioinfusions mitigated lethal pulmonary hypoplasia but were associated with preterm delivery. The lower rate of survival to discharge highlights the additional mortality burden independent of lung function. Additional long-term data are needed to fully characterize the outcomes in surviving neonates and assess the morbidity and mortality burden. Trial Registration: ClinicalTrials.gov Identifier: NCT03101891.

Maternal implications of placental transfusion.

Placental transfusion for 30-60 s after delivery is recommended by numerous professional societies and is now a common practice. Numerous studies document neonatal benefit with minimal maternal risk when routine neonatal stabilization and active management of the third stage of labor are undertaken during the period of delayed cord clamping. Maternal outcomes do not show any increased incidence of postpartum hemorrhage, or need for blood product transfusion in the case of vaginal delivery or cesarean section. Fetomaternal hemorrhage is also likely decreased with delayed cord clamping. In the case of fetal anomalies, cord management should be individualized according to each special circumstance, but is unlikely to lead to increased maternal morbidity. While few studies have investigated maternal outcomes with umbilical cord milking, this practice has not been as widely adopted. With careful monitoring of maternal and fetal well-being, a period of placental transfusion following delivery is advised for benefit of the neonate without significant maternal risk.

Prenatal Sonography in Suspected Proximal Gastrointestinal Obstructions: Diagnostic Accuracy and Neonatal Outcomes.

BACKGROUND: The purpose of this study was to assess diagnostic accuracy and neonatal outcomes in fetuses with a suspected proximal gastrointestinal obstruction (GIO). METHODS: After IRB approval, a retrospective chart review was conducted on prenatally suspected and/or postnatally confirmed cases of proximal GIO at a tertiary care facility (2012-2022). Maternal-fetal records were queried for presence of a double bubble ± polyhydramnios, and neonatal outcomes were assessed to calculate the diagnostic accuracy of fetal sonography. RESULTS: Among 56 confirmed cases, the median birthweight and gestational age at birth were 2550 g [interquartile range (IQR) 2028-3012] and 37 weeks (IQR 34-38), respectively. There was one (2%) false-positive and three (6%) false-negatives by ultrasound. Double bubble had a sensitivity, specificity, positive predictive value, and negative predictive value for proximal GIO of 85%, 98%, 98%, and 83%, respectively. Pathologies included 49 (88%) with duodenal obstruction/annular pancreas, three (5%) with malrotation, and three (5%) with jejunal atresia. The median postoperative length of stay was 27 days (IQR 19-42). Cardiac anomalies were associated with significantly higher complications (45% vs 17%, p = 0.030). CONCLUSIONS: In this contemporary series, fetal sonography has high diagnostic accuracy for detecting proximal gastrointestinal obstruction. These data are informative for pediatric surgeons in prenatal counseling and preoperative discussions with families. LEVEL OF EVIDENCE: Diagnostic Study, Level III.

Follow Your Nose: Repeat Nasal Bone Evaluation in First-Trimester Screening for Down Syndrome.

OBJECTIVE: Examine whether repeat nasal bone evaluation following an absent/uncertain nasal bone on first-trimester screening (FTS) improves Down syndrome (DS) screening specificity. METHODS: A retrospective chart review of FTS sonograms in one center from January 2015 to January 2018 was performed. Data was extracted for those with an absent/uncertain nasal bone. Repeat evaluations were offered. RESULTS: Of 6780 FTS sonograms, 589 (8.7%) had an absent/uncertain nasal bone. Upon repeat exam, 268/376 (71.3%) had a present nasal bone. Compared with Black patients, patients of other ethnicities were more likely to have a present nasal bone on exam 2 (P < .00001). Of 268 patients with a present nasal bone on exam 2, 37 (13.8%) had an abnormal DS risk following exam 1; 34/37 (91.9%) normalized following nasal bone visualization, dropping the screen positive rate to 1.1%. CONCLUSION: Repeat nasal bone examination is beneficial in refining DS risk assessment and improves the specificity of FTS.

A systematic review and meta-analysis of cell-free DNA testing for detection of fetal sex chromosome aneuploidy.

OBJECTIVES: The aim was to determine the accuracy of cell-free DNA testing (cfDNA) for detecting sex chromosome aneuploidies (SCA) in singleton pregnancies. METHODS: A systematic review and meta-analysis was performed to assess cfDNA accuracy for prenatal detection of 45,X, 47,XXY, 47,XXX and 47,XYY. Inclusion was restricted to studies published between January 2010 and December 2021 reporting both cfDNA and confirmatory diagnostic test results. RESULTS: For 45,X, the sensitivity was 98.8% (95%CI 94.6%-100%), specificity 99.4% (95%CI 98.7%-99.9%) and positive predictive value (PPV) 14.5% (95%CI 7.0%-43.8%). For 47,XXY, the sensitivity was 100% (95%CI 99.6%-100%), specificity 100% (95%CI 99.9%-100%) and PPV 97.7% (95%CI 78.6%-100%). For 47,XXX, the sensitivity was 100% (95%CI 96.9%-100%), specificity 99.9% (95%CI 99.7%-100%) and PPV 61.6% (95%CI 37.6%-95.4%). For 47,XYY, the sensitivity was 100% (95%CI 91.3%-100%), specificity 100% (95% CI 100%-100%) and PPV 100% (95%CI 76.5%-100%). All four SCAs had estimated negative predictive values (NPV) exceeding 99.99%, though false negatives were reported. CONCLUSIONS: This analysis suggests that cfDNA is a reliable screening test for SCA, though both false negatives and false positives were reported. These estimates of test performance are derived from pregnancies at high pretest risk for aneuploidy, limiting the generalisability to average risk pregnancies.

Obstetrical and neonatal outcomes of cardio-facio-cutaneous syndrome: Prenatal consequences of Ras/MAPK dysregulation.

We systematically delineated the prenatal phenotype, and obstetrical and neonatal outcomes of the RASopathy cardio-facio-cutaneous (CFC) syndrome. A comprehensive, retrospective medical history survey was distributed to parents of children with confirmed CFC in collaboration with CFC International, Inc. Data were collected on CFC gene variant, maternal characteristics, pregnancy course, delivery, and neonatal outcomes with the support of medical records. We identified 43 individuals with pathogenic variants in BRAF (81%), MEK1 (14%), or MEK2 (5%) genes. The median age was 8.5 years. Hyperemesis gravidarum, gestational diabetes, gestational hypertension, and preeclampsia occurred in 5/43 (12%), 4/43 (9%), 3/43 (7%), and 3/43 (7%) of pregnancies, respectively. Second and third trimester ultrasound abnormalities included polyhydramnios, macrocephaly, macrosomia, and renal and cardiac abnormalities. Delivery occurred via spontaneous vaginal, operative vaginal, or cesarean delivery in 15/42 (36%), 7/42 (16%), and 20/42 (48%), respectively. Median gestational age at delivery was 37 weeks and median birth weight was 3501 grams. Germline pathogenic vaiants had mutiple congenital consequences including polyhydramnios, renal and cardiac abnormalities, macrosomia, and macrocephaly on second and third trimester ultrasound. Elevated rates of operative delivery and neonatal complications were also noted. Understanding and defining a prenatal phenotype may improve prenatal prognostic counseling and outcomes.

Perceived Value of Prenatal Ultrasound Screening: A Survey of Pregnant Women.

INTRODUCTION: Routine prenatal screening ultrasounds primarily serve to diagnose major fetal anomalies which may prompt further testing and inform clinical decision-making, including possible pregnancy termination. Meanwhile, expectant parents may view the ultrasound experience and information gained differently from their clinicians. In this setting, how to best counsel patients, especially regarding the increasing findings of indeterminant clinical significance, is unclear. Greater understanding of women's views before undergoing their ultrasound may help to guide anticipatory counseling about the purpose of screening and interpretation of results. METHODS: We surveyed 289 patients presenting for scheduled prenatal ultrasounds at an academic tertiary care center. Discrete and open-ended questions assessed views surrounding the receipt of abnormal results and management of the pregnancy once fetal anomalies are detected. Qualitative responses were analyzed using thematic analysis. RESULTS: Most (95%) desired information about abnormal sonographic findings, although only half would consider pregnancy termination for anomalies. Reasons for wanting return of abnormal results included preparedness, valuing knowledge, and to a lesser extent, informing decision-making. When considering potential termination as a result of ultrasound findings, participants' rationales demonstrated deontological (seeing termination as inherently impermissible or permissible), relational (duties arising from the role of being a mother), and consequentialist (weighing harms and benefits) reasoning. CONCLUSION: This study highlights women's perceptions of prenatal ultrasounds as an inherently valuable source of information and preparedness, beyond their role in informing clinical decision-making. Identifying the ethical constructs underpinning patients' perspectives may help direct development of counseling tools responsive to individual needs and values regarding prenatal ultrasound findings.

Fetal akinesia deformation sequence syndrome associated with recessive TTN variants.

Arthrogryposis multiplex congenita (AMC) [also known as multiple joints contracture or Fetal Akinesia Deformation Sequence (FADS)] is etiologically a heterogeneous condition with an estimated incidence of approximately 1 in 3000 live births and much higher incidence when prenatally diagnosed cases are included. The condition can be acquired or secondary to fetal exposures and can also be caused by a variety of single-gene disorders affecting the brain, spinal cord, peripheral nerves, neuromuscular junction, muscle, and a variety of disorders affecting the connective tissues (Niles et al., Prenatal Diagnosis, 2019; 39:720-731). The introduction of next-generation gene sequencing uncovered many genes and causative variants of AMC but also identified genes that cause both dominant and recessive inherited conditions with the variability of clinical manifestations depending on the genes and variants. Molecular diagnosis in these cases is not only important for prognostication but also for the determination of recurrence risk and for providing reproductive options including preimplantation and prenatal diagnosis. TTN, the largest known gene in the human genome, has been known to be associated with autosomal dominant dilated cardiomyopathy. However, homozygote and compound heterozygote pathogenic variants with recessive inheritance have rarely been reported. We report the effect of recessive variants located within the fetal IC and/or N2BA isoforms in association with severe FADS in three families. All parents were healthy obligate carriers and none of them had cardiac or skeletal muscle abnormalities. This report solidifies FADS as an alternative phenotypic presentation associated with homozygote/compound heterozygous pathogenic variants in the TTN.

Not just a carrier: Clinical presentation and management of patients with heterozygous disease-causing alkaline phosphatase (ALPL) variants identified through expanded carrier screening.

Hypophosphatasia (HPP) is an underrecognized, complex bone mineralization disorder with variable manifestations caused by one or two deleterious variants in the alkaline phosphatase (ALPL) gene. Expanded carrier screening (ECS), inclusive of ALPL, intends to inform reproductive risk but may incidentally reveal an HPP diagnosis with 50% familial risks. We sought to investigate at-risk individuals and develop a multidisciplinary referral and evaluation protocol for ECS-identified ALPL heterozygosity. A retrospective database query of ECS results from 8 years to 1 month for heterozygous pathogenic/likely pathogenic ALPL variants was completed. We implemented a clinical protocol for diagnostic testing and imaging, counseling, and interdisciplinary care management for identified patients, and outcomes were documented. Heterozygous ALPL variants were identified in 12/2248 unrelated patients undergoing ECS (0.53%; heterozygote frequency 1/187). Of 10 individuals successfully contacted, all demonstrated symptomatology and/or alkaline phosphatase values consistent with HPP. ECS may reveal incidental health risks, including recognition of missed HPP diagnoses in ALPL heterozygotes. In our cohort, all ECS-identified ALPL heterozygotes with clinical and/or biochemical data available demonstrated features of HPP. Referral to a genetics professional familiar with HPP is indicated for family history assessment, genetic counseling, cascade testing, and long-term bone health management.

Prenatal phenotype of 47, XXY (Klinefelter syndrome).

OBJECTIVE: There is a paucity of knowledge regarding the prenatal presentation of Klinefelter syndrome, or 47, XXY. Accurate prenatal counseling is critical and in utero diagnosis is currently limited by a poor understanding of the prenatal phenotype of this condition. METHODS: This is a case series of fetuses with cytogenetically confirmed 47, XXY in the prenatal period or up to age 5 years, with prenatal records available for review from four academic institutions between 2006 and 2019. Ultrasound reports were reviewed in detail to assess for increased nuchal translucency and structural abnormalities. Additionally, we reviewed results of cell-free DNA and serum analyte testing when performed to inform our understanding of the detection of fetal 47, XXY through standard genetic screening tests. RESULTS: Forty-one cases with confirmed cytogenetic diagnosis of 47, XXY and prenatal records available for review were identified: 37 had a prenatal diagnosis and 4 had a postnatal diagnosis. Nuchal translucency was increased ≥3.0 mm in 23.1% (6/26) of cases with a documented measurement. In 29.2% (7/24) of cases with a second trimester anatomical ultrasound available for review, a fetal abnormality was identified (3 brain anomalies, 1 cardiac abnormality, 1 echogenic bowel, and 2 limb abnormalities). Among those who had cell-free DNA and serum analytes performed, 92.6% (25/27) and 36.3% (4/11) had an abnormal result respectively. CONCLUSION: This case series expands our knowledge of the prenatal presentation of 47, XXY by identifying first and second trimester fetal sonographic abnormalities. Prenatal identification of this condition enables accurate counseling, focused prenatal management, and early postnatal interventions to ameliorate some of the known complications.

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.

Genetics of non-isolated hemivertebra: A systematic review of fetal, neonatal, and infant cases.

Hemivertebra is a congenital vertebral malformation caused by unilateral failure of formation during embryogenesis that may be associated with additional abnormalities. A systematic review was conducted to investigate genetic etiologies of non-isolated hemivertebra identified in the fetal, neonatal, and infant periods using PubMed, Cochrane database, Ovid Medline, and ClinicalTrials.gov from inception through May 2022 (PROSPERO ID CRD42021229576). The Human Phenotype Ontology database was accessed May 2022. Studies were deemed eligible for inclusion if they addressed non-isolated hemivertebra or genetic causes of non-isolated hemivertebra identified in the fetal, neonatal, or infant periods. Cases diagnosed clinically without molecular confirmation were included. Systematic review identified 23 cases of non-isolated hemivertebra with karyotypic abnormalities, 2 cases due to microdeletions, 59 cases attributed to single gene disorders, 18 syndromic cases without known genetic etiology, and 14 cases without a known syndromic association. The Human Phenotype Ontology search identified 49 genes associated with hemivertebra. Non-isolated hemivertebra is associated with a diverse spectrum of cytogenetic abnormalities and single gene disorders. Genetic syndromes were notably common. Frequently affected organ systems include musculoskeletal, cardiovascular, central nervous system, genitourinary, gastrointestinal, and facial dysmorphisms. When non-isolated hemivertebra is identified on prenatal ultrasound, the fetus must be assessed for associated anomalies and genetic counseling is recommended.

The utility of pathologic examination and comprehensive phenotyping for accurate diagnosis with perinatal exome sequencing.

OBJECTIVE: Exome sequencing (ES) offers the ability to assess for variants in thousands of genes and is particularly useful in the setting of fetal anomalies. However, the ES pipeline relies on a thorough understanding of an individual patient's phenotype, which may be limited in the prenatal setting. Additional pathology evaluations in the pre- and postnatal settings can add phenotypic details important for clearly establishing and characterizing a diagnosis. METHODS: This is a case series of prenatal ES performed at our institution in which pathology evaluations, including autopsy, dysmorphology examination, histology, and peripheral blood smear, augmented the understanding of the fetal phenotype. ES was performed at our institution and a multidisciplinary panel reviewed and classified the variants for each case. RESULTS: We present four cases wherein pathology evaluations were beneficial for supporting a perinatal diagnosis identified with ES. In each of these cases, pathology findings provided additional data to support a more complete understanding of the relationship between the perinatal phenotype and variants identified with ES. CONCLUSION: These cases highlight challenges of perinatal ES related to incomplete prenatal phenotyping, demonstrate the utility of pathology evaluations to support diagnoses identified with ES, and further characterize the disease manifestations of specific genetic variants.