Genetic etiology and pregnancy outcomes of fetuses with central nervous system anomalies.

PURPOSE: To investigate genetic etiology and pregnancy outcomes of fetal central nervous system (CNS) anomalies. METHODS: 217 fetuses with CNS anomalies were included in our cohort from January 2016 to December 2022. 124 cases received karyotyping and 73 cases simultaneously underwent copy number variant sequencing (CNV-seq). Dynamic ultrasound screening and pregnancy outcomes were followed up, including neonates' neurodevelopmental outcomes. RESULTS: (1) 20 types of CNS anomalies were revealed by ultrasound and the most common was ventriculomegaly. (2) 14 (11.3%) of 124 cases were found chromosomal abnormalities by karyotyping, and copy number variations (CNVs) were revealed in 13 (17.8%) of 73 cases by CNV-seq. Fetuses with non-isolated CNS anomalies had a higher detection rate (DR) of abnormal karyotypes and CNVs than those with isolated CNS anomalies (25.0% vs. 4.8%; 35.0% vs. 11.3%) (P < 0.05). And the DR of abnormal karyotypes was significantly higher in multiple CNS anomalies than in single CNS anomaly (16.7% vs. 2.8%, P < 0.05), while there were no significant differences in the DR of CNVs. (3) Through dynamic ultrasound, 12 cases were further found progression or additional malformations. (4) Pregnancy outcomes of 209 cases were obtained, including 136 (65.1%) live births, 3 (1.4%) intrauterine fetal deaths, and 70 (33.5%) terminated. Two neonatal deaths at 6 months and one infant with motor and intellectual disabilities were finally found after long-term follow-up. CONCLUSION: Genetic analysis combined with dynamic ultrasound screening and multidisciplinary consultation plays an important role in evaluating the prognosis of fetal CNS anomalies, especially for those with multiple CNS or extracranial abnormalities.

Congenital cerebral and cerebellar anomalies in relation to bovine viral diarrhoea virus and Akabane virus in newborn calves.

Congenital malformations occur sporadically in cattle; however, congenital structural and functional disorders of the nervous system are rather common in ruminants. Among the numerous causes of congenital nervous system defects, infectious agents are highlighted in this paper. Virus-induced congenital malformations are well known, among which those caused by bovine viral diarrhoea virus (BVDV), Akabane virus (AKAV), Schmallenberg virus (SBV), Bluetongue virus (BTV), and Aino virus (AV) are the most studied. In this study, we specify and categorise macroscopic and histopathological lesions in the brain of 42 newborn calves suffering from severe neurologic signs and diagnosed with BVDV and AKAV infection. Following a complete necropsy, specimens were collected from the brains to track the presence of BVDV, AKAV and SBV utilising reverse transcription polymerase chain reaction. Of the 42 examined calves, 21 were BVDV positive and 6 were AKAV positive, while 15 brains were negative for the studied agents. Regardless of the aetiology, cerebellar hypoplasia, hydranencephaly, hydrocephalus, porencephaly, and microencephaly were detected. Cerebellar hypoplasia was the most common lesion seen in both BVDV-positive and AKAV-positive cases. Virus-induced necrosis of the germinative cells of the external granular layer of cerebellum, as well as vascular damages, are believed to be the underlying causes of cerebellar hypoplasia. BVDV was the most important aetiological agent of such cases in this study.

Biallelic loss-of-function variants in EXOC6B are associated with impaired primary ciliogenesis and cause spondylo-epi-metaphyseal dysplasia with joint laxity type 3.

Spondylo-epi-metaphyseal dysplasias with joint laxity, type 3 (SEMDJL3) is a genetic skeletal disorder characterized by multiple joint dislocations, caused by biallelic pathogenic variants in the EXOC6B gene. Only four individuals from two families have been reported to have this condition to date. The molecular pathogenesis related to primary ciliogenesis has not been enumerated in subjects with SEMDJL3. In this study, we report two additional affected individuals from unrelated families with biallelic pathogenic variants, c.2122+15447_2197-59588del and c.401T>G in EXOC6B identified by exome sequencing. One of the affected individuals had an intellectual disability and central nervous system anomalies, including hydrocephalus, hypoplastic mesencephalon, and thin corpus callosum. Using the fibroblast cell lines, we demonstrate the primary evidence for the abrogation of exocytosis in an individual with SEMDLJ3 leading to impaired primary ciliogenesis. Osteogenesis differentiation and pathways related to the extracellular matrix were also found to be reduced. Additionally, we provide a review of the clinical and molecular profile of all the mutation-proven patients reported hitherto, thereby further characterizing SEMDJL3. SEMDJL3 with biallelic pathogenic variants in EXOC6B might represent yet another ciliopathy with central nervous system involvement and joint dislocations.

Evaluation of prenatal central nervous system anomalies: obstetric management, fetal outcomes and chromosome abnormalities.

OBJECTIVE: To study the outcomes of fetuses who were diagnosed with central nervous system (CNS) anomalies during prenatal period and to describe the obstetric management of those pregnancies. METHODS: In this retrospective study, fetuses who were detected to have central nervous system anomalies by prenatal ultrasound from January 2010 to December 2019 were recruited. Data regarding prenatal diagnosis and obstetric outcomes were retrieved from maternal and paediatric records. The prognosis of fetuses who were born alive was classified based on their neurodevelopmental outcome within two years of life. RESULTS: There were a total of 365 fetuses with CNS anomalies within the 10-year study period, with a mean gestational age of 24.65±7.37 weeks at diagnosis. Ventriculomegaly (23.36%) was the commonest CNS anomalies seen. 198 (54.20%) of these fetuses had associated extra-CNS anomalies, with cardiovascular being the most common system involved. Fetal karyotyping was performed in 111 pregnancies, with chromosomal aberrations detected in 53 (49.07%) cases and culture failure in 3 cases. Majority of the chromosomal abnormalities were Edward syndrome (trisomy 18) and Patau syndrome (trisomy 13). Fetuses with congenital CNS anomalies and abnormal chromosomal karyotyping were more likely to be diagnosed earlier by prenatal ultrasound and tend to have poorer obstetric and neurocognitive prognosis. Prenatally, 86 (23.56%) of the cases were lost to follow up and likely to deliver elsewhere. Among the 279 cases whom their pregnancy outcomes were available, 139 (49.82%) pregnancies resulted in live births, 105 (37.63%) pregnancies were electively terminated, while the remaining 35 (12.54%) pregnancies ended in spontaneous loss. The decision of termination of pregnancy largely depends on mean diagnostic gestational age, presence of chromosomal aberrations and abnormal amniotic fluid volume in those fetuses. Two years after delivery, only 75 (53.96%) children out of 139 live births were still alive, 43 (30.93%) died and 21 (15.11%) cases were lost to follow-up. 32 (23.02%) children with prenatally diagnosed CNS anomalies had normal neurodevelopmental outcome. The presence of multiple CNS anomalies and involvement of extra-CNS anomalies indicated a poorer neurodevelopmental prognosis. CONCLUSION: Less than 50% of fetuses with prenatally diagnosed CNS anomalies resulted in live births. Even if they survive till delivery, 36.45% of them passed away within 2 years and 62.79% of children who survived till 2 years old had neurodevelopmental disability.

Investigation of copeptin levels in foetal congenital central nervous system anomalies.

Copeptin has been shown to be associated with central nervous system pathologies. The aim of this study was to investigate the relationship between serum CCP levels and central nervous system (CNS) anomalies. In this case-control study, those at 9-14 weeks of gestation serum levels of copeptin, were assessed in pregnant women whose foetuses subsequently developed CNS anomalies (group 1: n = 60) and compared with gestational age-matched pregnant women who exhibited normal pregnancy outcomes (group 2: n = 48). The mean copeptin levels were 1.58 ± 0.40 ng/mL and 1.11 ± 0.36 ng/mL in the CNS anomalies and control groups, respectively (p < .0001). An increased level of copeptin independently predicts development of CNS anomalies, suggesting that copeptin can be used for prediction and discrimination of CNS anomalies in normal pregnancies at 9-14 weeks of gestation.Impact statementWhat is already known on this subject? There is no test or method to diagnose CNS anomalies in the first trimester of pregnancy. This study presents the first and new information on the relationship between serum copeptin levels and central nervous system anomalies in pregnant women whose foetuses subsequently developed CNS anomalies.What do the results of this study add? I have strongly demonstrated differences in maternal CPP levels between CNS anomalous pregnancies and healthy controls.What are the implications of these findings for clinical practice and/or further research? It has been thought that copeptin appears to be an ideal marker for central nervous system anomaly prediction at 9-14 weeks of gestational age and if confirmed in larger prospective studies. Finally, these results could not be used as parameters for prenatal CNS screening. Advanced studies, well-structured and conducted on larger populations are needed to investigate the issue further.

Associated anomalies in cases with agenesis of the corpus callosum.

Agenesis of corpus callosum (ACC) is an uncommon congenital anomaly, its etiology is unclear and its pathogenesis is controversial. Cases with ACC often have other non-ACC associated congenital anomalies. The purpose of this study was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with ACC were collected in all live births, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population-based registry of congenital malformations. Of the 99 cases with ACC, representing a prevalence of 2.56 per 10,000, 73 (73.7%) had associated anomalies. There were 16 (16.2%) cases with chromosomal abnormalities, and 13 (13.2%) nonchromosomal recognized dysmorphic conditions including syndromes two each: Aicardi, Dandy-Walker, and fetal alcoholism. Forty-four (44.4%) of the cases had nonsyndromic multiple congenital anomalies (MCA). Anomalies in the musculoskeletal, the urogenital, the central nervous, the cardiovascular, and the digestive systems were the most common other anomalies in the cases with MCA. The anomalies associated with ACC could be classified into a recognizable malformation syndrome in 29 out of the 73 cases (39.7%) with associated anomalies. This study included special strengths: it is population-based, each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion the overall prevalence of associated anomalies, three of four cases, emphasizes the need for a screening for other anomalies in cases with ACC.

Magnetic resonance imaging in the second trimester as a complement to ultrasound for diagnosis of fetal anomalies.

Background: Fetal ultrasound has limitations, especially if the patient is obese or in cases with oligohydramnios. Magnetic resonance imaging (MRI) can then be used as a complement, but only few studies have focused on examinations in the second trimester. Purpose: To validate MRI as a complement to diagnose fetal anomalies in the second trimester. Material and Methods: This retrospective study retrieved data from January 2008 to July 2012 from the Fetal Medicine Unit and Department of Radiology at Uppsala University Hospital. Ultrasound and MRI findings were reviewed in 121 fetuses in relation to the final diagnosis, including postpartum follow-up and autopsy results. Results: Of the 121 fetuses, 51 (42%) had a CNS anomaly and 70 (58%) a non-CNS anomaly diagnosed or suspected. MRI provided additional information in 21% of all cases without changing the management and revealed information that changed the management of the pregnancy in 13%. When a CNS anomaly was detected or suspected, the MRI provided additional information in 22% and changed the management in 10%. The corresponding figures for non-CNS cases were 21% and 16%, respectively. The proportion of cases with additional information that changed the management was especially high in patients with a BMI >30 kg/m2 (25%) and in patients with oligohydramnios (38%). In five cases in category III, false-positive ultrasound findings were identified. Conclusions: MRI in the second trimester complements ultrasound and improves diagnosis of fetal CNS- and non-CNS anomalies especially when oligohydramnios or maternal obesity is present.

Fetal MRI Analysis of Corpus Callosal Abnormalities: Classification, and Associated Anomalies.

BACKGROUND: Corpus callosal abnormalities (CCA) are midline developmental brain malformations and are usually associated with a wide spectrum of other neurological and non-neurological abnormalities. The study aims to highlight the diagnostic role of fetal MRI to characterize heterogeneous corpus callosal abnormalities using the latest classification system. It also helps to identify associated anomalies, which have prognostic implications for the postnatal outcome. METHODS: In this study, retrospective data from antenatal women who underwent fetal MRI between January 2014 and July 2023 at Rush University Medical Center were evaluated for CCA and classified based on structural morphology. Patients were further assessed for associated neurological and non-neurological anomalies. RESULTS: The most frequent class of CCA was complete agenesis (79.1%), followed by hypoplasia (12.5%), dysplasia (4.2%), and hypoplasia with dysplasia (4.2%). Among them, 17% had isolated CCA, while the majority (83%) had complex forms of CCA associated with other CNS and non-CNS anomalies. Out of the complex CCA cases, 58% were associated with other CNS anomalies, while 8% were associated with non-CNS anomalies. 17% of cases had both. CONCLUSION: The use of fetal MRI is valuable in the classification of abnormalities of the corpus callosum after the confirmation of a suspected diagnosis on prenatal ultrasound. This technique is an invaluable method for distinguishing between isolated and complex forms of CCA, especially in cases of apparent isolated CCA. The use of diffusion-weighted imaging or diffusion tensor imaging in fetal neuroimaging is expected to provide further insights into white matter abnormalities in fetuses diagnosed with CCA in the future.

Conventional Chromosome Analysis of Fetuses with Central Nervous System Anomalies and Associated Anomalies: Is Anything Changed?

Central nervous system (CNS) abnormalities are often isolated but can accompany various genetic syndromes. In this study, we evaluated conventional karyotype results and associated findings of fetuses that were diagnosed with CNS abnormalities. Cases included in the study were diagnosed with fetal CNS anomalies and underwent conventional karyotyping. Conventional karyotype results of subjects were compared with karyotype results of fetal karyotyped patients as a result of maternal anxiety in a two-year period. In this period, 69 patients were diagnosed with fetal CNS anomalies and 64 of them underwent invasive fetal karyotyping. Of these, 32 patients had isolated CNS anomalies, while 32 were associated with other anomalies. There was no significant difference between karyotype results when compared with the control group (p = 0.76). Apart from some specific anomalies, the aneuploidy rate does not significantly differ between fetuses with CNS anomalies and the control group. Advanced genetic evaluation may provide additional diagnostic benefits, especially for this group.

Clinical findings in children with congenital anomalies and misoprostol intrauterine exposure: a study of 38 cases.

The authors describe the clinical findings of 38 children with congenital anomalies and misoprostol intrauterine exposure. This study included 38 cases, ascertained from case series of the Hospital of Rehabilitation of Craniofacial Anomalies from University of São Paulo, with evidence of intrauterine exposure to misoprostol in the first trimester of the pregnancy. Information about misoprostol intake and drug administration route was obtained through interviews with mothers. Clinical evaluation showed 18 individuals with facial phenotype compatible with Moebius syndrome; 11 individuals with multiple congenital anomalies; and nine individuals with nonsyndromic cleft lip and/or cleft palate. This study showed a widening of the phenotypic spectrum associated with misoprostol embryotoxicity.