Exome sequencing identifies the first genetic determinants of sirenomelia in humans.

Sirenomelia is a rare severe malformation sequence of unknown cause characterized by fused legs and severe visceral abnormalities. We present a series of nine families including two rare familial aggregations of sirenomelia investigated by a trio-based exome sequencing strategy. This approach identified CDX2 variants in the two familial aggregations, both fitting an autosomal dominant pattern of inheritance with variable expressivity. CDX2 is a major regulator of caudal development in vertebrate and mouse heterozygotes are a previously described model of sirenomelia. Remarkably, the p.(Arg237His) variant has already been reported in a patient with persistent cloaca. Analysis of the sporadic cases revealed six additional candidate variants including a de novo frameshift variant in the genetically constrained NKD1 gene, encoding a known interactor of CDX2. We provide the first insights for a genetic contribution in human sirenomelia and highlight the role of Cdx and Wnt signaling pathways in the development of this disorder.

Prenatal therapy with pyrimethamine + sulfadiazine vs spiramycin to reduce placental transmission of toxoplasmosis: a multicenter, randomized trial.

BACKGROUND: The efficacy of prophylaxis to prevent prenatal toxoplasmosis transmission is controversial, without any previous randomized clinical trial. In France, spiramycin is usually prescribed for maternal seroconversions. A more potent pyrimethamine + sulfadiazine regimen is used to treat congenital toxoplasmosis and is offered in some countries as prophylaxis. OBJECTIVE: We sought to compare the efficacy and tolerance of pyrimethamine + sulfadiazine vs spiramycin to reduce placental transmission. STUDY DESIGN: This was a randomized, open-label trial in 36 French centers, comparing pyrimethamine (50 mg qd) + sulfadiazine (1 g tid) with folinic acid vs spiramycin (1 g tid) following toxoplasmosis seroconversion. RESULTS: In all, 143 women were randomized from November 2010 through January 2014. An amniocentesis was later performed in 131 cases, with a positive Toxoplasma gondii polymerase chain reaction in 7/67 (10.4%) in the pyrimethamine + sulfadiazine group vs 13/64 (20.3%) in the spiramycin group. Cerebral ultrasound anomalies appeared in 0/73 fetuses in the pyrimethamine + sulfadiazine group, vs 6/70 in the spiramycin group (P = .01). Two of these pregnancies were terminated. Transmission rates, excluding 18 children with undefined status, were 12/65 in the pyrimethamine + sulfadiazine group (18.5%), vs 18/60 in the spiramycin group (30%, P = .147), equivalent to an odds ratio of 0.53 (95% confidence interval, 0.23-1.22) and which after adjustment tended to be stronger (P = .03 for interaction) when treatment started within 3 weeks of seroconversion (95% confidence interval, 0.00-1.63). Two women had severe rashes, both with pyrimethamine + sulfadiazine. CONCLUSION: There was a trend toward lower transmission with pyrimethamine + sulfadiazine, but it did not reach statistical significance, possibly for lack of statistical power because enrollment was discontinued. There were also no fetal cerebral toxoplasmosis lesions in the pyrimethamine + sulfadiazine group. These promising results encourage further research on chemoprophylaxis to prevent congenital toxoplasmosis.

Impact of prenatal diagnosis on the outcome of patients with a transposition of great arteries: A 24-year population-based study.

BACKGROUND: Transposition of great arteries (TGA) defined as the combination of concordant atrioventricular and discordant ventriculo-arterial connections is one of the most common congenital heart defects. Prenatal diagnosis of TGA remains difficult. To determine the impact of antenatal diagnosis we evaluated the sensitivity of antenatal detection and the neonatal mortality of TGA considering two study periods and two major types of TGA. METHODS: A cross-sectional study was performed. Data were collected from a French population-based birth defect registry. From 1988 to 2012, 94 fetuses with TGA were registered. The study period was subdivided into the 1988 to 1999 period and the 2000 to 2012 period. Two types of TGA were considered: isolated TGA (n = 66) and associated TGA (n = 28). A stratified analysis was performed considering the study periods and the types of TGA. RESULTS: Considering the study periods, the sensitivity of prenatal detection of TGA increased significantly (9.8% vs. 51.5%, p = 0.0001). The same trend was found for associated TGA (4.8% vs. 33.3%, p = 0.002) and isolated TGA (21.1% vs. 100%, p < 0.001). A late diagnosis of TGA (7 days after birth) was observed in 13.2% of cases. Neonatal mortality decreased significantly over time for isolated TGA (25.0% vs. 0 p = 0.01). Prenatal diagnosis of both types of TGA did not improve survival. CONCLUSION: We demonstrated that prenatal diagnosis and neonatal mortality of TGA varied greatly according to the malformation type and the study period. This could be explained by an improvement in terms of medical management.

Prenatal Screening of 21 Microdeletion/Microduplication Syndromes and Subtelomeric Imbalances by MLPA in Fetuses with Increased Nuchal Translucency and Normal Karyotype.

Fetuses with increased nuchal translucency thickness (NT) are at increased risk for chromosomal abnormalities. In case of a normal karyotype, a minority of them may present with structural abnormalities or genetic syndromes, which may be related to submicroscopic chromosomal imbalances. The objective of this study was to evaluate whether MLPA screening of 21 syndromic and subtelomeric regions could improve the detection rate of small chromosomal aberrations in fetuses with increased NT and a normal karyotype. A total of 106 prenatal samples from fetuses with NT ≥ 99th centile and normal R- and G-banding were analyzed by MLPA for subtelomeric imbalances (SALSA P036 and P070) and 21 syndromic regions (SALSA P245). One sample showed a benign CNV (dup(8)pter, FBXO25 gene), and 1 patient was found to have a loss of 18 qter and a gain of 5 pter as a result of an unbalanced translocation. The incidence of cryptic pathogenic variants was <1% or 2.7% when only fetuses with other ultrasound abnormalities were taken into account. Submicroscopic imbalances in fetuses with increased NT may be individually rare, and genome-wide screening seems more likely to improve the diagnostic yield in these fetuses.

Prenatal diagnosis of the VACTERL association using routine ultrasound examination.

BACKGROUND: The prognosis and early neonatal management of the VACTERL association depend mainly on the severity of malformations ascertained prenatally. METHODS: Here we reviewed the spectrum of clinical features observed in cases of VACTERL association ascertained prenatally through ultrasound examination but examined at birth and compared them with cases ascertained postnatally. RESULTS: From 1995 to 2011, a total of 19 cases of VACTERL association were observed in our center; 10 were ascertained prenatally and confirmed after birth whereas 9 were ascertained only after birth. The types and frequencies of malformations observed prenatally were as follows: renal malformations (45%), tracheoesophageal fistula (44%), cardiac malformations (20%), vertebral (13%), and limb (11%) defects. Anal atresia was never detected using routine prenatal ultrasound examination. CONCLUSION: Further studies of fetuses with the VACTERL association are necessary to better delineate the malformations spectrum observed prenatally to improve the early recognition of the VACTERL association.

False positive morphologic diagnoses at the anomaly scan: marginal or real problem, a population-based cohort study.

BACKGROUND: Congenital malformations occur in 3-4% of live births. Their prenatal detection is performed by ultrasound screening. Any announcement about a suspected malformation is a source of stress for the parents, and misdiagnosis during ultrasound screening can lead to expensive and sometimes iatrogenic medical interventions. In this study, we aim to determine the false-positive rate, first overall and then by anatomical system, of ultrasound screening for congenital malformations in the second and third trimesters of pregnancy. METHODS: Our sample includes all children born between 1 January, 2006, and 31 December, 2009, in the French region of Auvergne, whose mother had a prenatal ultrasound diagnosis of a congenital malformation during the second or third trimester of pregnancy confirmed by a follow-up ultrasound examination by an expert consultant ultrasonographer. The study included 526 fetuses, divided in 3 groups: false positives, diagnostic misclassifications, and true positives. The rates of false positives and diagnostic misclassifications were calculated for the sample as a whole and then by anatomical system. RESULTS: Overall, the false-positive rate was 8.8% and the rate of diagnostic misclassification 9.2%. The highest false-positive rates were found for renal and gastrointestinal tract malformations, and the highest diagnostic misclassification rates for cerebral and cardiac malformations. The diagnostic misclassification rate was significantly higher than the false-positive rate for cardiac malformations. CONCLUSION: The false-positive rate during prenatal ultrasound is not insignificant; these misdiagnoses cause psychological stress for the parents and overmedicalisation of the pregnancy and the child.

Prenatal ultrasound findings observed in the Wolf-Hirschhorn syndrome: data from the registry of congenital malformations in Auvergne.

BACKGROUND: Wolf-Hirschhorn syndrome (WHS) is associated with facial dysmorphism including high forehead, high nasal bridge, hypertelorism and severe mental retardation. WHS results from a 4p16.3 deletion. Only a small number of reports have been made on the prenatal ultrasound findings observed in WHS. CASES: Here we report our experience on 10 cases of WHS ascertained prenatally between 1983 and 2009 through the CEMC-Auvergne registry of congenital malformations. CONCLUSION: The assumption that a "Greek warrior helmet" facies is pathognomonic of WHS could lead to misdiagnosis. Other clinical findings such as severe and early onset intrauterine growth retardation, facial dysmorphism (high forehead, high nasal bridge, low-set ears, micrognathia, hypertelorism), atrial or ventricular septal defect, and renal dysplasia should help obstetricians to suspect the diagnosis of WHS prenatally.

Analysis of the cost effectiveness of different strategies for the antenatal diagnosis of chromosomal aberrations in cases of ultrasound-identified fetal abnormalities.

OBJECTIVE: Principal objective of this work was to analyse the cost effectiveness of different sequences of cytogenetic techniques from the hospital's point of view, after prenatal ultrasound has identified fetal malformations. METHODS: Cytogenetic tests were performed for each case in 3 strategies, and their results are reported and compared to one reference strategy. Two new simulated strategies were considered: chromosomal microarrays alone and a direct test + CMA. MAIN OUTCOMES MEASURES: cost-effectiveness ratio. RESULTS: A single test result was positive in 234 of the 835 pregnancies studied (28%). CMA alone would have identified 239 abnormalities. In the simulated direct test + CMA sequence, the direct test alone would have been positive for 66.1% of the abnormalities identified. When testing was indicated for NT, reference strategy (Direct + karyotyping) costs 1 084.8 euros by positive test results. Strategies Direct + CMA and CMA alone cost respectively 992.7 and 550.0 euros by positive test results. For OUM indications, reference strategy costs 2 937.8 euros by positive test results. Strategies Direct + CMA and CMA alone cost respectively, 2 118.4 and 1 304.7 euros by positive test results. CONCLUSIONS: CMA appears to be the most effective test for prenatal cytogenetic diagnosis of fetal abnormalities identified by ultrasound.

Normal intellectual skills in patients with Rhombencephalosynapsis.

OBJECTIVES: Rhombencephalosynapsis (RES) is a very rare cerebellar malformation. Neurodevelopmental outcome of apparently isolated RES remains poorly documented and standardized cognitive assessment, reported in only nine published cases so far, is lacking. Prenatal counselling is challenging considering the uncertain prognosis of isolated RES. The aim of this study was to focus on cognitive and motor outcome of isolated RES with a clinical description of six new cases and a detailed review of the literature. METHODS: A single-centre retrospective study of all RES patients over a 15-year period. Ataxia and fine motor skills were scored using a five-grade scale, according to the degree of disturbance of daily living. Intelligence Quotient (IQ) was established according to age-related Weschler Intelligence Scales. A systematic literature review included published cases with relevant outcome data. RESULTS: Six new cases of apparently isolated RES were reported, including three diagnosed in prenatal settings. The onset age for walking was delayed in four patients. Three patients had head shaking and three had a strabismus. One patient had a mild motor disability, one had subtle ataxia that did not impair daily life and four patients had a normal neurological examination at the last visit. Intellectual abilities were normal in all patients (full IQ score from 90 to 142), although three had ADHD. All received standard schooling. Based on these six new cases, as well as cases from 12 publications in the literature, a total of 28 patients with non-syndromic RES were analysed. Concerning motor outcome, 72% had no complaint or minimal impairment, 16% moderate and 12% severe impairment. Concerning cognitive outcome, 68% had normal cognitive skills, 18% borderline intellectual functioning and 14% moderate to severe disability.

Strategy for Use of Genome-Wide Non-Invasive Prenatal Testing for Rare Autosomal Aneuploidies and Unbalanced Structural Chromosomal Anomalies.

Atypical fetal chromosomal anomalies are more frequent than previously recognized and can affect fetal development. We propose a screening strategy for a genome-wide non-invasive prenatal test (NIPT) to detect these atypical chromosomal anomalies (ACAs). Two sample cohorts were tested. Assay performances were determined using Cohort A, which consisted of 192 biobanked plasma samples-42 with ACAs, and 150 without. The rate of additional invasive diagnostic procedures was determined using Cohort B, which consisted of 3097 pregnant women referred for routine NIPT. Of the 192 samples in Cohort A, there were four initial test failures and six discordant calls; overall sensitivity was 88.1% (37/42; CI 75.00-94.81) and specificity was 99.3% (145/146; CI 96.22-99.88). In Cohort B, there were 90 first-pass failures (2.9%). The rate of positive results indicating an anomaly was 1.2% (36/3007) and 0.57% (17/3007) when limited to significant unbalanced chromosomal anomalies and trisomies 8, 9, 12, 14, 15, 16, and 22. These results show that genome-wide NIPT can screen for ACAs with an acceptable sensitivity and a small increase in invasive testing, particularly for women with increased risk following maternal serum screening and by limiting screening to structural anomalies and the most clinically meaningful trisomies.

Laryngotracheoesophageal cleft, a rare differential diagnosis of esophageal atresia.

A laryngotracheoesophageal cleft, commonly called laryngeal cleft (LC), is a congenital malformation of the posterior part of the larynx creating an abnormal communication between the laryngotracheal axis and the pharyngoesophageal axis. The prenatal ultrasonographic features associating absent stomach, polyhydramnios and mediastinal "pouch sign" are usually considered pathognomonic for esophageal atresia. This observation demonstrates that they can also correspond to a severe form of laryngotracheoesophageal cleft extending to the carina.

Simultaneous, congenital, mucocoele of the Blandin-Nühn glands and teratoma of the tongue: early management and follow up at one year.

Mucocoele of the Blandin-Nühn glands and teratomas of the tongue are rare in newborn babies. We present what is to our knowledge the first documented case of both at the same time, and describe management and follow up over 12 months after the birth. Prenatal diagnosis defined the treatment plan during delivery to establish an airway for the baby promptly. A normal delivery is possible if the cyst is anterior, and can be punctured during delivery. Delayed excision reduces the possibility of oedema and obstruction of the airway, ensures complete resection, avoids recurrence, and confirms the diagnosis. Mucocoeles are classified as extravasation or retention types; our observation supports the hypothesis of a "malformative type". A long follow-up is essential to monitor macroglossia, open bite, and the development of the mandible.

Congenital unilateral renal agenesis: Prevalence, prenatal diagnosis, associated anomalies. Data from two birth-defect registries.

BACKGROUND: The different mechanisms leading to a solitary kidney should be differentiated because the long-term outcome might be different. The fetal period is the best moment to make a true diagnosis of congenital unilateral renal agenesis (URA). The objective was to determine the prevalence of URA at birth. The secondary objectives were to describe the evolution of sensitivity of prenatal diagnosis over time and the different forms of URA (isolated and associated with other malformations) detected up to 1 year. METHODS: The cases were retrospectively identified through two French population-based birth defect registries (Auvergne and Bas-Rhin) between 1995 and 2013. Stillbirths and fetuses up to 22 weeks of gestation and infants up to 1 year old with URA were included. RESULTS: A total of 177 cases of URA were registered. The prevalence at birth was 4.0/10,000. The overall prenatal prevalence was 3.6/10,000 (isolated URA: 2.8/10,000). URA were isolated (59.9%), associated with isolated contralateral congenital anomaly of kidney or urinary tract (CAKUT) (7.3%) and with other extra-renal anomalies (32.8%). The total proportion of contralateral CAKUT was 15%. Only three cases presented an aneuploidy, prenatally detected and conducting to a termination of pregnancy. The sensitivity of prenatal diagnosis improved over time (from 54.2% in 1995 to 1997 to 95.8% in 2010 to 2013; p = 0.002). CONCLUSION: Our study provides estimates of prevalence of URA at birth. A longitudinal cohort from the antenatal period to puberty should be performed to determine the prognosis of the contralateral kidney among these children with isolated, associated with contralateral CAKUT and URA with extra-renal anomalies. Birth Defects Research 109:1204-1211, 2017. © 2017 Wiley Periodicals, Inc.

The changes in angiogenic gene expression in recurrent multiple chorioangiomas.

OBJECTIVES: To assess the messenger ribonucleic acid expression in placental tissue of growth factors, cytokines, angiogenic and anti-angiogenic factors in one case of recurrent multiple chorioangiomas. METHODS: Complementary deoxyribonucleic acid array analysis was performed on the affected placentae and on normal placentaes (controls) to compare messenger ribonucleic acid levels of 96 genes involved in angiogenesis. RESULTS: Eleven genes presented more than two-fold alteration in expression levels: undetectable (angiopoietin 1, osteonectin, tyrosine kinase endothelial, neuropilin 1), decreased (transcription growth factor beta receptor 3, tissue inhibitor of metalloproteinase type 2, EGF receptor, integrin-alpha V, tyrosine kinase vascular endothelial growth factor receptor 2), increased (angiopoietin 2, osteopontin). CONCLUSIONS: We illustrated the complexity of angiogenic disruption in recurrent multiple chorioangiomas leading to the difficulty to propose a single candidate gene to explain this pathology.