Central Nervous System Malformations Research Articles

Schizencephaly: Etiopathogenesis, Classification, Therapeutic, and Rehabilitative Approach

AbstractSchizencephaly is an uncommon anomaly in neuronal migration characterized by complete clefts that extend from the pia mater to the ependymal surface of the ventricular system. These clefts are encompassed by displaced gray matter and filled with cerebrospinal fluid. Typically, they are found most often in the frontal lobe or the area around the lateral sulcus and can occur on one or both sides. The size, location, and type of these clefts carry significant clinical and prognostic implications. Moreover, they are frequently associated with other central nervous system malformations, including the absence of the septum pellucidum, septo-optic dysplasia, optic nerve hypoplasia, pachygyria, polymicrogyria, cortical dysplasia, heterotopia, and dysplasia of the corpus callosum. Occurrence of schizencephaly is almost always sporadic but its etiopathogenesis is yet to be fully understood. Most likely environmental factors, including exposure to teratogens, viral infections, and maternal factors, operate jointly with genetic defects. To date COL4A1, EMX2, SHH, and SIX3 are the genes identified as possible pathogenetic target. It is interesting to notice that schizencephaly is commonly seen in abandoned or adopted children, as proof of causative effect of intrautero insults. Clinical presentations widely vary and symptoms include a spectrum of cognitive impairment, limb paresis/tetraparesis, and epileptic seizures either with early or late onset; anyway, none of these symptoms is ever-present and patients with schizencephaly can also have normal neurocognitive and motor development. Diagnostic gold standard for schizencephaly is magnetic resonance imaging, which allows to identify and characterize typical clefts. Treatment of schizencephaly is symptomatic and supportive and depends on the severity of morbidity resulting from the malformation. Therapy includes antiepileptic drugs, psychomotor rehabilitation, and in selected cases surgical approach.

Foreword: A Special Issue on Central Nervous System Malformations

Foreword: A Special Issue on Central Nervous System Malformations

Introduction: A Practical Guide to Central Nervous System Malformations—From Genetics, to Diagnosis and Treatment

AbstractCentral nervous system (CNS) malformations encompass diverse congenital anomalies impacting brain and spinal cord development, profoundly affecting neurological function. They arise from disruptions in embryonic neural tube formation, neuronal migration, and cortical organization. This abstract provides a comprehensive overview of CNS malformations, covering classification, etiology, clinical manifestations, and diagnostic challenges. CNS malformations fall into distinct groups: neural tube defects (e.g., anencephaly, spina bifida), resulting from incomplete neural tube closure; malformations of cortical development (e.g., lissencephaly, polymicrogyria), featuring irregularities in cortical folding; and anomalies affecting structures like the corpus callosum, cerebellum, and CNS vasculature, alongside conditions such as hydrocephalus and Chiari malformations. Genetic factors, including mutations in LIS1, DCX, and RELN, contribute significantly, while environmental factors like maternal folic acid deficiency also play a role. Some malformations occur in genetic syndromes (e.g., tuberous sclerosis, neurofibromatosis). Clinical presentations vary, with neural tube defects typically presenting severe deficits at birth, while cortical malformations manifest as intellectual disabilities, seizures, and motor deficits. Hydrocephalus elevates intracranial pressure, and Chiari malformations cause headaches and neurological symptoms. Diagnosis necessitates a multidisciplinary approach involving clinical evaluation, neuroimaging, genetic testing, and histopathological analysis. Prenatal diagnosis via ultrasound and magnetic resonance imaging is crucial for planning interventions, while postnatal diagnosis relies on clinical and imaging findings.Understanding CNS malformations is vital for early detection, intervention, and comprehensive care provision. Advances in genetics and neuroimaging offer hope for improved outcomes and better quality of life for affected individuals.

Opioid analgesic exposure during the first trimester of pregnancy and the risk of major congenital malformations in infants: a systematic review and meta-analysis†.

Prescribed opioid analgesics are frequently used to manage pain in pregnancy. However, the available literature regarding the teratogenic potential of opioid use during pregnancy has not been systematically summarised. This systematic review and meta-analysis aimed to assess the quality of the evidence on these potential risks and calculate a pooled estimate of risk for any opioid analgesic and individual opioids. We searched PubMed, Embase and CINAHL for published studies assessing the risk of major congenital malformations in infants following first-trimester exposure to opioid analgesics compared with a reference group, excluding studies examining opioid agonist therapy or illicit opioid use. We assessed the risk of bias using the Risk of Bias in Non-Randomised Studies of Intervention tool. We pooled adjusted risk estimates from studies rated at serious risk of bias or better in a random-effects meta-analysis. Of 12 identified studies, 11 were at high risk of bias (eight serious; three critical). Relative to unexposed infants, those exposed to any opioid use during the first trimester of pregnancy were not at an increased risk of major congenital malformations overall (relative risk 1.04, 95%CI 0.98-1.11); cardiovascular malformations (relative risk 1.07, 95%CI 0.96-1.20); or central nervous system malformations (relative risk 1.06, 95%CI 0.92-1.21). Raised risk estimates were observed for gastrointestinal malformations (relative risk 1.40, 95%CI 0.38-5.16) and cleft palate (relative risk 1.57, 95%CI 0.48-5.13) following any opioid exposure and atrial septal defects (relative risk 1.20, 95%CI 1.05-1.36) following codeine exposure. Although the meta-analysis did not indicate substantial increased risk for most malformations examined, this risk remains uncertain due to the methodological limitations of the included studies. Healthcare professionals and pharmaceutical regulators should be aware of the issues related to the quality of research in this field.

Central Nervous System Malformations Associated with Diabetic Embryopathy in Latin American Mothers without Glycemic Control: A Review

Objetivo: Describir las malformaciones del sistema nervioso asociadas a embriopatía diabética en madres sin adecuado control glicémico en Latinoamérica. Material y métodos: Se realizó una revisión minuciosa de publicaciones en reconocidas bases de datos en línea en español y en inglés. Los buscadores utilizados incluyeron MEDLINE, PubMed, Scielo, BVS, HINARI, EBSCO, Google Scholar. Se encontraron artículos de tipo descriptivo, observacional, retrospectivo, guías de práctica clínica, revisión sistemática, casos y controles, y metaanálisis. Resultados: Mediante la revisión sistematizada de artículos, se obtuvo que las malformaciones del sistema nervioso central secundarias a la embriopatía diabética guardan una relacion estrecha con diversos factores de riesgo de la mujer latinoamericana. Conclusiones: Se encontró asociación entre las características epidemiológicas multifactoriales de la mujer latinoamericana y el desarrollo de malformaciones del sistema nervioso central secundarias a embriopatia diabetica, resultantes de multiples procesos fisiopatológicos desencadenados por la hipeglicemia materna.

Risk factors associated with congenital central nervous system abnormalities in the National Hospital of Zinder, Niger

IntroductionCongenital malformations of the central nervous system (CNS) are morphological abnormalities of the brain and spinal cord that occur during fetal development. They constitute the second most common congenital disability, after congenital cardiac defects. Many risk factors have been identified; however, these studies included various types of congenital abnormality. Furthermore, there is a lack of information on risk factors for congenital CNS malformation, and notably in the Zinder region of Niger. ObjectiveThis study aimed to identify the risk factors associated with congenital CNS malformations in the Zinder region. MethodsIn a case-control design, patients with congenital CNS malformation were enrolled between June 2022 and April 2023 in the Department of Neurosurgery of the National Hospital of Zinder. ResultsFamily history of malformation (aOR:3.31, 95% CI:1.25−8.78) and consanguine marriage (aOR:2.28, 95% CI:1.23−4.20) were significantly associated with congenital CNS malformation. In contrast, folic acid supplementation (aOR:0.34, 95% CI:0.13, 0.89), multiparity (aOR:0.34, 95% CI:0.13, 0.89), and grand multiparity (aOR, 0.47; 95% CI:0.23, 0.97) had a protective effect. ConclusionRisk factors such as family malformation history and consanguine marriage increased the risk of developing congenital malformations of the central nervous system. In contrast, folic acid supplementation in the index period and multiparity had a significant protective effect.

SMC1A epilepsy syndrome: clinical data from a large international cohort.

SMC1A epilepsy syndrome or developmental and epileptic encephalopathy-85 with or without midline brain defects (DEE85, OMIM #301044) is an X-linked neurologic disorder associated with mutations of the SMC1A gene, which is also responsible for about 5% of patients affected by Cornelia de Lange syndrome spectrum (CdLS). Only described in female patients, SMC1A epilepsy syndrome is characterized by the onset of severe refractory epileptic seizures in the first year of life, global developmental delay, a variable degree of intellectual disability, and dysmorphic facial features not typical of CdLS. This was a descriptive observational study for the largest international cohort with this specific disorder. The main goal of this study was to improve the knowledge of the natural history of this phenotype with particular attention to the psychomotor development and the epilepsy data. The analyzed cohort shows normal prenatal growth with the subsequent development of postnatal microcephaly. The incidence of neonatal problems (seizures and respiratory compromise) is considerable (51.4%). There is a significant prevalence of central nervous system (20%) and cardiovascular malformations (20%). Motor skills are generally delayed. The presence of drug-resistant epilepsy is confirmed; the therapeutic role of a ketogenic diet is still uncertain. The significant regression of previously acquired skills following the onset of seizures has been observed. Facial dysmorphisms are variable and no patient shows a classic CdLS phenotype. To sum up, SMC1A variants caused drug-resistant epilepsy in these patients, more than two-thirds of whom were shown to progress to developmental and epileptic encephalopathy. The SMC1A gene variants are all different from each other (apart from a couple of monozygotic twins), demonstrating the absence of a mutational hotspot in the SMC1A gene. Owing to the absence of phenotypic specificity, whole-exome sequencing is currently the diagnostic gold standard.

First Trimester Use of Buprenorphine or Methadone and the Risk of Congenital Malformations

Use of buprenorphine or methadone to treat opioid use disorder is recommended in pregnancy; however, their teratogenic potential is largely unknown. To compare the risk of congenital malformations following in utero exposure to buprenorphine vs methadone. This population-based cohort study used health care utilization data from publicly insured Medicaid beneficiaries in the US from 2000 to 2018. A total of 13 360 pregnancies with enrollment from 90 days prior to pregnancy start through 1 month after delivery and first trimester use of buprenorphine or methadone were included and linked to infants. Data were analyzed from July to December 2022. A pharmacy dispensing of buprenorphine or a code for administration of methadone in the first trimester. Primary outcomes included major malformations overall and malformations previously associated with opioids (any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, clubfoot, and oral clefts). Secondary outcomes included other organ system-specific malformations. Risk differences and risk ratios (RRs) were estimated comparing buprenorphine with methadone, adjusting for confounders with propensity score overlap weights. The cohort included 9514 pregnancies with first-trimester buprenorphine exposure (mean [SD] maternal age, 28.4 [4.6] years) and 3846 with methadone exposure (mean [SD] maternal age, 28.8 [4.7] years). The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone. After confounding adjustment, buprenorphine was associated with a lower risk of malformations compared with methadone (RR, 0.82; 95% CI, 0.69-0.97). Risk was lower with buprenorphine for cardiac malformations (RR, 0.63; 95% CI, 0.47-0.85), including both ventricular septal defect (RR, 0.62; 95% CI, 0.39-0.98) and secundum atrial septal defect/nonprematurity-related patent foramen ovale (RR, 0.54; 95% CI, 0.30-0.97), oral clefts (RR, 0.65; 95% CI, 0.35-1.19), and clubfoot (RR, 0.55; 95% CI, 0.32-0.94). Results for neural tube defects were uncertain given low event counts. In secondary analyses, buprenorphine was associated with a decreased risk of central nervous system, urinary, and limb malformations but a greater risk of gastrointestinal malformations compared with methadone. These findings were consistent in sensitivity and bias analyses. In this cohort study, the risk of most malformations previously associated with opioid exposure was lower in buprenorphine-exposed infants compared with methadone-exposed infants, independent of measured confounders. Malformation risk is one factor that informs the individualized patient decision regarding medications for opioid use disorder in pregnancy.

Review of Teratogenic Effects of Leflunomide, Accutane, Thalidomide, Warfarin, Tetracycline, and Angiotensin-Converting Enzyme Inhibitors.

Teratogenic agents have been shown to have drastic and detrimental effects on fetuses if exposed to the agent during uterine life. The most sensitive time for a developing fetus is during the first trimester, and teratogenic exposure during this time can lead to severe deformities in the fetus. The Food and Drug Administration has categorized teratogenic agents based on the severity of their effecton the fetus; these categories include A, B, C, D, and X. Category A is the safest, with the most dangerous, and highly contraindicated in pregnant patients being Category X. This review article will discuss the teratogenic agents leflunomide, isotretinoin, thalidomide, warfarin, tetracycline, and angiotensinogen-converting enzyme inhibitors. Leflunomide can cause cranioschisis, exencephaly, and vertebral, head, and limb malformations. Isotretinoin's main teratogenic effects include central nervous system malformations, hydrocephalus, eye abnormalities, cardiac septal defects, thymus abnormalities, spontaneous abortions, and external ear abnormalities. Thalidomide has been shown to cause limb deformities, bowel atresia, and heart defects when the embryo is exposed to the agent during development.Warfarin can lead to spontaneous abortion and intrauterine death, as well as nasal hypoplasia, hypoplasia of extremities, cardiac defects, scoliosis, and mental retardation when exposed in utero. Tetracycline's teratogenic effects include gastrointestinal distress, esophageal ulceration and strictures, teeth discoloration, hepatotoxicity, and calcifications. Angiotensinogen-converting enzyme inhibitors can cause skull hyperplasia, anuria, hypotension, renal failure, lung hypoplasia, skeletal deformation, oligohydramnios, and fetal death. Teratogenic effects can be avoided if the pregnant patient is educated on the teratogenic effects of these agents.

Prenatal dispositions and genetic analysis of monozygotic female twins with suprasellar cysts and hydrocephalus: A case report

IntroductionWe present a unique case of monozygotic female twins with virtually identical clinical and radiological presentations of supratentorial hydrocephalus and cystic formations from the suprasellar cistern.DiscussionEvaluating genetic predispositions and prenatal exposures is crucial for hydrocephalus in twins. Familial cases imply a genetic contribution to the development of these anomalies, including chromosomal abnormalities and specific variants linked to arachnoid cyst formation in various syndromes. Extensive genetic analyses found no pathogenic variants in the twins. Prenatal exposure to anti-epileptic medication was known during pregnancy and may be associated with fetal abnormalities, but not central nervous system (CNS) malformations, and was therefore not considered the cause of the condition in the twins. The twins presenting simultaneously with hydrocephalus caused by suprasellar cysts (SAC) underwent a two-step surgical management: initial ventriculoperitoneal shunt (VPS) placement followed by fenestration. Postoperative imaging showed cyst reduction, but a secondary VPS was necessary in both cases.ConclusionGenetic analysis is less likely to identify a monogenic etiology in non-syndromic cases of SACs, which are assumed to be multifactorial. There is no established evidence linking a teratogenic effect of anti-epileptic drugs to CNS malformations. Moreover, the surgical treatment of this complex condition constitutes a point of discussion.

Perinatal Prognosis of Pregnancies with Single Umbilical Artery in a Romanian Third-Level Unit.

Objectives: Single umbilical artery (SUA) is considered the most common abnormality of the umbilical artery. The objective of the study was to evaluate the perinatal prognosis of fetuses with SUA and to describe the associated malformations. The significance of the study is represented by examining whether our findings are in correlation with data already described.Methods: We performed a prospective cohort study on singleton pregnancies complicated with SUA. The study population was composed of women with singleton pregnancies who were examined at the Department of Obstetrics and Gynecology of the Târgu Mures County Emergency Clinical Hospital between 2012 and 2021.Results: The incidence of SUA in the study population was 0.48%. C-section was performed in 40 cases with SUA and in 5258 cases with no SUA (RR:1.56, P<0.05.) From the total number of 2249 premature deliveries, 23 newborns were diagnosed with SUA (RR:2.12, P<0.05.) From the total number of 869 deliveries with low birth weight (LBW) newborns, 13 were associated with SUA (RR: 3.12, P<0.05.) There were 206 pregnancies noted with antenatal fetal demise after 24 weeks of gestation, and only 2 of them were with SUA (RR:2.01, P>0.05.) Fetal and neonatal malformations were described in 290 cases, and 28 were associated with SUA (R:21.96, P<0.05.) In 57 of 85 cases (67.05%), we found iSUA, and 28 newborns (32.95%) had minor, major, or other associated pathologies. We found two cases of trisomy 18 and one case with trisomy 13 associated with SUA. Investigating the malformations associated with SUA, the most common were cardiac and great vessels malformations (12), followed by limb malformations (8), urogenital malformations (7), digestive tract malformations (7), central nervous system malformations (4), and in one case we found cleft palate.Conclusions: Perinatal prognosis regarding SUA is significantly poorer than in cases without this pathology. One-third of fetuses with SUA were associated with fetal anomalies. The most common pathologies associated with SUA were cardiovascular, limb, urogenital, and digestive system malformations. Our data are similar to those described in other studies; therefore, we conclude, we can implement the general recommendations in our region regarding counselling patients.

Aplasia cutis congenita and central nervous system malformations on a multiple pregnancy with fetus papyraceus: Case report

A fetal death in utero causes a prothrombotic environment due to abnormal placental anastomoses with hypoperfusion, which determines multisystem malformations, including dermal and subcutaneous involvement such as aplasia cutis and a central nervous system (CNS) abnormalities. We present the case of a quadruple pregnancy with death of a fetus at week 16, from which 3 live newborns were obtained, twin #1 with aplasia cutis type V. Twin #2 who did not present complications or associated malformations and twin # 3 with radiological documentation of dysgenesis of the corpus callosum. Based on literature, there is a relationship between chorionicity and the history of a papyraceous fetus and the multisystemic congenital malformations.

Optik sinir hipoplazisi;Olgu sunumu

Optic nerve hypoplasia (ONH) is a rare neurodevelopmental disorder described by the optic disc is abnormally small regardless of sex or race. Imaging methods are frequently used in the diagnosis. In our case, a 17-year-old male patient, came to the clinic because of a deviation in his left eye, the examination showed hypoplasia of the optic nerve in the left eye. In ON hypoplasia, reported cases may include severe Central nervous system (CNS) malformations. However, we recommend periodic systemic examinations along with occupational rehabilitation, parental education and mobility training for these unique children.

The impact of epilepsy and antiseizure medications on pregnancy and neonatal outcomes: A nationwide cohort study.

Our objective was to assess the adverse outcomes during pregnancy, as well as for the fetus and neonates, in women with epilepsy, both with and without the use of antiseizure medications (ASMs). A cohort of singleton pregnancies between January 1, 2004 and December 31, 2014 was identified using the Taiwan National Health Database. The pregnancies were categorized into ASM exposure, ASM nonexposure, and control (consisting of women without an epilepsy diagnosis) groups. We recorded adverse outcomes in neonates and documented pregnancy complications. The generalized estimating equation with logit link was used to estimate adjusted odds ratios. There were 629 singleton pregnancies in the group exposed to ASMs, 771 in the epilepsy group without ASM exposure, and 2,004,479 in the control group. Women with epilepsy had a significantly higher risk of puerperal cerebrovascular diseases (adjusted odds ratios in the exposure and nonexposure groups=54.46 and 20.37, respectively), respiratory distress syndrome (5.1 and 2.99), mortality (3.15 and 3.22), sepsis (2.67 and 2.54), pregnancy-related hypertension (1.71 and 1.8), preeclampsia (1.87 and 1.79), cesarean delivery (1.72 and 2.15), and preterm labor (1.38 and 1.56). The use of ASMs may increase the risk of eclampsia (adjusted odds ratio=12.27). Compared to controls, fetuses/neonates born to women with epilepsy had a higher risk of unexplained stillbirth (adjusted odds ratios in the exposure and nonexposure groups=2.51 and 2.37, respectively), congenital anomaly (1.37 and 1.33), central nervous system malformation (3.57 and 2.25), low birth weight (1.90 and 1.97), and a low Apgar score at 5 min (2.63 and 1.3). The use of ASMs may introduce an additional risk of small for gestational age; the adjusted odds ratio was 1.51. Women with epilepsy, irrespective of their exposure to ASMs, had a slightly elevated risk of pregnancy and perinatal complications. Puerperal cerebrovascular diseases may be a hidden risk for women with epilepsy.

Functional analysis of germline VANGL2 variants using rescue assays of vangl2 knockout zebrafish.

Developmental studies have shown that the evolutionarily conserved Wnt Planar Cell Polarity (PCP) pathway is essential for the development of a diverse range of tissues and organs including the brain, spinal cord, heart and sensory organs, as well as establishment of the left-right body axis. Germline mutations in the highly conserved PCP gene VANGL2 in humans have only been associated with central nervous system malformations, and functional testing to understand variant impact has not been performed. Here we report three new families with missense variants in VANGL2 associated with heterotaxy and congenital heart disease p.(Arg169His), non-syndromic hearing loss p.(Glu465Ala) and congenital heart disease with brain defects p.(Arg135Trp). To test the in vivo impact of these and previously described variants, we have established clinically-relevant assays using mRNA rescue of the vangl2 mutant zebrafish. We show that all variants disrupt Vangl2 function, although to different extents and depending on the developmental process. We also begin to identify that different VANGL2 missense variants may be haploinsufficient and discuss evidence in support of pathogenicity. Together, this study demonstrates that zebrafish present a suitable pipeline to investigate variants of unknown significance and suggests new avenues for investigation of the different developmental contexts of VANGL2 function that are clinically meaningful.

Chromosome Microarray Analysis and Exome Sequencing: Implementation in Prenatal Diagnosis of Fetuses with Digestive System Malformations.

(1) Purpose: Retrospective back-to-back comparisons were performed to evaluate the accuracy, effectiveness, and incremental yield of chromosome microarray analysis (CMA) and exome sequencing (ES) analysis in fetuses with digestive system malformations (DSMs). (2) Methods: In total, 595 women with fetal DSMs who underwent prenatal diagnosis were enrolled. We analyzed the diagnostic yields of CMA and ES and evaluated pregnancy outcomes. Copy number variants (CNVs) were classified according to the American College of Medical Genetics and Genomics guidelines. (3) Results: Pathogenic CNVs were detected in 11/517 (2.12%) fetuses, and variants of unknown significance (VUS) were identified in 69 (13.35%) fetuses using CMA. ES detected 29 pathogenic/likely pathogenic variants in 23/143 (16.08%) fetuses and 26/143 (18.2%) VUS. In those with other ultrasound abnormalities, the detection rate of multiple system structural malformations was 41.2%, followed by skeletal (33.3%), cardiovascular (25.4%), and central nervous system (18.6%) malformations. Of the 391 surviving children, 40 (10.2%) exhibited varying degrees of mental retardation. (4) Conclusion: A correlation exists between DSMs and chromosomal abnormalities. When combined with other systemic abnormalities, the incidence of chromosomal abnormalities increases significantly. Patients with congenital DSM are at risk of developing neurodevelopmental disorders. Combined CMA and ES detection of fetal DSM has good clinical application potential.

Epilepsy Frequency and Risk Factors Three Years After Neonatal Seizures

BackgroundNeonatal seizures, one of the main risk factors for the development of epilepsy, remain a clinical concern. In children with neonatal seizures, early recognition of risk factors is important for the early diagnosis and appropriate treatment of epilepsy and for improving prognosis. In this study, we aimed to determine the frequency of and the risk factors for the development of epilepsy in patients with neonatal seizures. MethodsThe hospital files of 228 children who experienced seizures in the neonatal period were reviewed. The frequency of epilepsy and risk factors for the development of epilepsy were determined at age 36 months. ResultsEpilepsy was diagnosed in 40.8% of the cases. Univariate analysis revealed family history of epilepsy, parental consanguinity, abnormal neurological examination findings, microcephaly, unresponsiveness to antiepileptic drugs or antiseizure medication, use of more than one antiepileptic drugs to antiseizure medication at discharge, status epilepticus, electroencephalography abnormalities, abnormal neuroimaging findings, invasive ventilation requirement, myoclonic seizures, central nervous system malformation, and congenital metabolic disease as risk factors for the development of epilepsy. Of these, a family history of epilepsy, abnormal neurological examination findings at discharge, and use of at least two antiepileptic drugs to antiseizure medication at discharge were found as independent risk factors in multivariate analysis. ConclusionsNeonatal seizures appear to be associated with epilepsy in more than one-third of the patients. Of the newborns with seizures, those with a family history of epilepsy, abnormal neurological examination findings at discharge, and those using at least two antiepileptic drugs to antiseizure medication at discharge should be monitored more carefully for the development of epilepsy.

Identification of novel TMEM231 gene splice variants and pathological findings in a fetus with Meckel Syndrome.

Background: Meckel Syndrome (MKS, OMIM #249000) is a rare and fatal autosomal recessive ciliopathy with high clinical and genetic heterogeneity. MKS shows complex allelism with other related ciliopathies such as Joubert Syndrome (JBTS, OMIM #213300). In MKS, the formation and function of the primary cilium is defective, resulting in a multisystem disorder including occipital encephalocele, polycystic kidneys, postaxial polydactyly, liver fibrosis, central nervous system malformations and genital anomalies. This study aimed to analyze the genotype of MKS patients and investigate the correlation between genotype and phenotype. Methods: A nonconsanguineous couple who conceived four times with a fetus affected by multiorgan dysfunction and intrauterine fetal death was studied. Whole exome sequencing (WES) was performed in the proband to identify the potentially pathogenic variant. Sanger sequencing was performed in family members. In silico tools were used to analyse the pathogenicity of the identified variants. cDNA TA-cloning sequencing was performed to validate the effects of intronic variants on mRNA splicing. Quantitative real-time PCR was performed to investigate the effect of the variants on gene expression. Immunofluorescence was performed to observe pathological changes of the primary cilium in kidney tissue from the proband. Results: Two splice site variants of TMEM231 (NM_001077418.2, c.583-1G>C and c.583-2_588delinsTCCTCCC) were identified in the proband, and the two variants have not been previously reported. The parents were confirmed as carriers. The two variants were predicted to be pathogenic by in silico tools and were classified as pathogenic/likely pathogenic variants according to the American College of Medical Genetics and Genomics guideline. cDNA TA cloning analysis showed that both splice site variants caused a deletion of exon 5. RT-PCR revealed that the expression of TMEM231 was significantly decreased and immunofluorescence showed that the primary cilium was almost absent in the proband's kidney tissue. Conclusion: We reported the clinical, genetic, molecular and histochemical characterisation of a family affected by MKS. Our findings not only extended the mutation spectrum of the TMEM231 gene, but also revealed for the first time the pathological aetiology of primary cilia in humans and provide a basis for genetic counselling of the parents to their offspring.

Incidence of Neonatal Seizures in China Based on Electroencephalogram Monitoring in Neonatal Neurocritical Care Units

Neonatal seizures pose a significant challenge in critical care, and continuous video electroencephalography (cEEG) monitoring holds promise for early detection of seizures. However, large-scale data on the incidence of neonatal seizures and monitoring systems in China are lacking. To determine the incidence of neonatal seizures in infants with high risk in China. A large, cross-sectional multicenter study was conducted from January 2017 to December 2018 in the neonatal intensive care units (NICUs) of 7 tertiary medical centers in China. Neonates with high risk were included, and cEEG monitoring was conducted. Data were collected between January 1, 2017, and January 31, 2020. The data were analyzed between January 2021 and January 2022. The incidence of neonatal seizures, categorized by etiology, and seizure burden. A total of 20 310 neonates with high risk were included (10 495 [51.7%] male; mean [SD] postmenstrual age, 37.7 [3.7] weeks), and seizures were observed in 3423 infants (16.9%). The highest proportion of seizures was attributed to acute neonatal encephalopathy (1448 [42.3%]). The incidence of seizures decreased with postmenstrual age and birth weight, with the highest occurrence observed in neonates with postmenstrual age of less than 28 weeks (237 of 879 [27.0%]) or birth weight of less than 1.0 kg (269 of 914 [29.4%]). Preterm infants had a higher proportion of moderate and severe seizure burdens compared with full-term infants (moderate severity: 248 of 1199 [20.7%] vs 454 of 2224 [20.4%]), but no significant differences were observed in etiology. Seizure burden was highest with genetic syndromes (49 of 188 [26.1%]), central nervous system malformations (33 of 127 [26.0%]), and inborn errors of metabolism (27 of 113 [23.9%]). During hospitalization, 7.8% of neonates with seizures died (267 neonates), with 81.3% of these cases having a moderate or severe seizure burden (217 neonates). Mortality was generally higher in preterm vs full-term infants (98 of 1199 [8.2%] vs 169 of 2224 [7.6%]) and increased with the severity of seizure burden (217 of 267 neonates with moderate or severe burden [81.3%]). This cross-sectional study of neonatal seizures underscores the substantial burden seizures pose to high-risk infants with brain injury in China, particularly those who are born prematurely or who have congenital conditions.

Novel USP9X Mutation in A Lebanese Patient with Delay and Microcephaly: Case Report and Review of Literature

Introduction: USP9X gene is located on the X-chromosome and encodes for an enzyme that regulates important substrates involved in neuronal growth and development. Thus, rare USP9X mutations were identified as directly causative of neurodevelopmental disorders (NDDs) and Intellectual Disability (ID) in homozygous males and more rarely in heterozygous females. In males, USP9X variants have been linked to an X-linked mental retardation syndrome that includes; central nervous system (CNS) abnormalities (white matter disturbances, thin corpus callosum, widened ventricles, and cerebellar defects), global delay with significant alteration of speech, language and behavior, hypotonia, joint hypermobility, digital abnormalities, gastro-intestinal symptoms, visual system defects and dysmorphic facial features. Patient Data: We report the rare case of a 3 years old and 8 months male patient presenting with NDD, ID, speech delay, progressive aggressive behavioral changes and CNS abnormalities (microcephaly, left periventricular lesion). He was found to have a USP9X variant carrying a missense mutation: USP9X, c.1870A&gt;T p.(Met624Leu) on Whole-Exome Sequencing (WES). Discussion: Our patient had most of the important features of the previously described X-linked mental retardation syndrome but some were absent such as dysmorphic features, digital or visual abnormalities and hypotonia. Microcephaly rather than macrocephaly was noted, which could be an additional potential CNS malformation, expanding the spectrum of phenotypic characteristics of the USP9X variants. No associated congenital anomalies were noted that are usually more common in female subjects. Conclusion: This is to our knowledge the first reported case of a USP9X variant in Lebanon. The clinical characteristics matched most of the previously described features in the literature. Microcephaly was a new clinical feature not previously described and could be a new possible phenotypic characteristic of the disease.