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

Three Prime Repair Exonuclease 1 (TREX1) gene mutations have been associated with Aicardi-Goutières Syndrome (AGS) - a rare, severe pediatric autoimmune disorder that primarily affects the brain and has a poorly understood etiology. Microglia are brain-resident macrophages indispensable for brain development and implicated in multiple neuroinflammatory diseases. However, the role of TREX1 - a DNase that cleaves cytosolic nucleic acids, preventing viral- and autoimmune-related inflammatory responses - in microglia biology remains to be elucidated. Here, we leverage a model of human embryonic stem cell (hESC)-derived engineered microglia-like cells, bulk, and single-cell transcriptomics, optical and transmission electron microscopy, and three-month-old assembloids composed of microglia and oligodendrocyte-containing organoids to interrogate TREX1 functions in human microglia. Our analyses suggest that TREX1 influences cholesterol metabolism, leading to an active microglial morphology with increased phagocytosis in the absence of TREX1. Notably, regulating cholesterol metabolism with an HMG-CoA reductase inhibitor, FDA-approved atorvastatin, rescues these microglial phenotypes. Functionally, TREX1 in microglia is necessary for the transition from gliogenic intermediate progenitors known as pre-oligodendrocyte precursor cells (pre-OPCs) to precursors of the oligodendrocyte lineage known as OPCs, impairing oligodendrogenesis in favor of astrogliogenesis in human assembloids. Together, these results suggest routes for therapeutic intervention in pathologies such as AGS based on microglia-specific molecular and cellular mechanisms.

The innate immune system relies on molecular sensors to detect distinctive molecular patterns, including viral double-stranded RNA (dsRNA), which triggers responses resulting in apoptosis and immune infiltration. Adenosine Deaminases Acting on RNA (ADARs) catalyze the deamination of adenosine (A) to inosine (I), serving as a mechanism to distinguish self from non-self RNA and prevent aberrant immune activation. Loss-of-function mutations in the ADAR1 gene are one cause of Aicardi Goutières Syndrome (AGS), a severe autoimmune disorder in children. Although seven out of the eight AGS-associated mutations in ADAR1 occur within the catalytic domain of the ADAR1 protein, their specific effects on the catalysis of adenosine deamination remain poorly understood. In this study, we carried out a biochemical investigation of four AGS-causing mutations (G1007R, R892H, K999N, and Y1112F) in ADAR1 p110 and truncated variants. These studies included adenosine deamination rate measurements with two different RNA substrates derived from human transcripts known to be edited by ADAR1 p110 (glioma-associated oncogene homologue 1 (hGli1), 5-hydroxytryptamine receptor 2C (5-HT2cR)). Our results indicate that AGS-associated mutations at two amino acid positions directly involved in stabilizing the base-flipped conformation of the ADAR-RNA complex (G1007R and R892H) had the most detrimental impact on catalysis. The K999N mutation, positioned near the RNA binding interface, altered catalysis contextually. Finally, the Y1112F mutation had small effects in each of the assays described here. These findings shed light on the differential effects of disease-associated mutations on adenosine deamination by ADAR1, thereby advancing our structural and functional understanding of ADAR1-mediated RNA editing.

We identified a de novo heterozygous transient receptor potential cation channel subfamily M (melastatin) member 3 (TRPM3) missense variant, p.(Asn1126Asp), in a patient with developmental delay and manifestations of cerebral palsy (CP) using phenotype-driven prioritization analysis of whole-genome sequencing data with Exomiser. The variant is localized in the functionally important ion transport domain of the TRPM3 protein and predicted to impact the protein structure. Our report adds TRPM3 to the list of Mendelian disease-associated genes that can be associated with CP and provides further evidence for the pathogenicity of the variant p.(Asn1126Asp).

BACKGROUND AND PURPOSE: Although cardinal imaging features for the diagnostic criteria of the Dandy-Walker phenotype have been recently defined, there is a large range of unreported malformations among these patients. The brainstem, in particular, deserves careful attention because malformations in this region have potentially important implications for clinical outcomes. In this article, we offer detailed information on the association of brainstem dysgenesis in a large, multicentric cohort of patients with the Dandy-Walker phenotype, defining different subtypes of involvement and their potential clinical impact. MATERIALS AND METHODS: In this established multicenter cohort of 329 patients with the Dandy-Walker phenotype, we include and retrospectively review the MR imaging studies and clinical records of 73 subjects with additional brainstem malformations. Detailed evaluation of the different patterns of brainstem involvement and their potential clinical implications, along with comparisons between posterior fossa measurements for the diagnosis of the Dandy-Walker phenotype, was performed among the different subgroups of patients with brainstem involvement. RESULTS: There were 2 major forms of brainstem involvement in patients with Dandy-Walker phenotype including the following: 1) the mild form with anteroposterior disproportions of the brainstem structures only (57/73; 78%), most frequently with pontine hypoplasia (44/57; 77%), and 2) the severe form with patients with tegmental dysplasia with folding, bumps, and/or clefts (16/73; 22%). Patients with severe forms of brainstem malformation had significantly increased rates of massive ventriculomegaly, additional malformations involving the corpus callosum and gray matter, and interhemispheric cysts. Clinically, patients with the severe form had significantly increased rates of bulbar dysfunction, seizures, and mortality. CONCLUSIONS: Additional brainstem malformations in patients with the Dandy-Walker phenotype can be divided into 2 major subgroups: mild and severe. The severe form, though less prevalent, has characteristic imaging features, including tegmental folding, bumps, and clefts, and is directly associated with a more severe clinical presentation and increased mortality.

Objective To assess prenatal ultrasonographic findings and postnatal outcomes in fetuses with intracranial hemorrhage (ICH). Methods This retrospective study included fetuses prenatally diagnosed with ICH between December 2012 and August 2023. Maternal characteristics, prenatal ultrasonographic findings, and postnatal outcomes were reviewed. Results Twenty-seven fetuses with ICH were reviewed. Intracranial hemorrhage was classified as grade 3 and 4 in 24 fetuses. Twenty-two fetuses had ICH, four had ICH with subdural hemorrhage, and one had ICH with subarachnoid hemorrhage. Ventriculomegaly was the most common ultrasonographic finding, and was observed in 22 of the 27 (81.5%) fetuses. Seven fetuses were lost to follow-up, and four intrauterine fetal deaths occurred. The remaining 16 fetuses were delivered at a median gestational age of 35+2 weeks. The infants were followed-up for 40.1 months (range, 4-88). Nine of the 16 infants underwent ventriculoperitoneal placement. One infant underwent brain surgery for severe epilepsy. Motor impairment, including cerebral palsy, was observed in 13 infants (81.2%). Neurologic impairment occurred in six infants (37.5%), developmental delay in nine (56.2%), and epilepsy in 11 (68.7%). Conclusion Fetal ICH is a rare complication diagnosed during pregnancy, which results in subsequent fetal neurological sequelae or death. This study demonstrated that the common ultrasonographic findings in fetal ICH were progressive ventriculomegaly and increased periventricular echogenicity. Fetuses diagnosed with prenatal ICH, especially those affected by higher-grade ICH, may be at an increased risk of long-term neurodevelopmental problems.

OBJECTIVE: To determine the structural abnormalities on magnetic resonance imaging (MRI) in the epileptic Pakistani pediatric population presenting at Tertiary Care Hospital, Karachi. METHODS: This cross-sectional descriptive study was done at the CT & MRI Center, Dr Ruth K.M Pfau Civil Hospital Karachi, from February 2019 to January 2020. This study enrolled 173 subjects of either gender between 1-14 years of age with epilepsy who underwent an MRI of the brain. An MRI brain with epilepsy protocol was performed after taking a history from each patient. Abnormalities were reported according to their imaging features, signal intensity, and location. RESULTS: Of the 173 subjects, 94 (54.3%) were boys and 79 (45.7%) were girls, with mean age of 6.7±3.3 years. Generalized seizures were predominant (n=103; 59.5%), followed by focal seizures (n=57; 33%), and unknown seizure patterns (n=13; 7.5%). MRI findings were unremarkable in 68 (39.3%) cases, predominantly in both generalized (35.84%) and focal (2.31%) epilepsy cases. Structural abnormalities were evident in 105 (60.7%) patients on MRI. Cerebral atrophy was predominant (11.56%), especially in generalized epilepsy cases. Encephalomalacia (6.94%) and ventricular enlargement (6.36%) were observed, with encephalomalacia more prevalent in focal epilepsy and ventricular enlargement in generalized epilepsy. Mesial temporal sclerosis (5.7%) was significant in focal epilepsy cases. The highest prevalence of unremarkable MRI findings was in the 6-10 years’ age group (20.2%). CONCLUSION: MRI detected abnormalities in 60.7% cases of paediatric epilepsy, most commonly cerebral atrophy and encephalomalacia, emphasizing MRI's role in assessing epilepsy-related structural changes and the need for targeted interventions.

Upregulation of Notch signaling is associated with brain arteriovenous malformation (bAVM), a disease that lacks pharmacological treatments. Tetracycline (tet)-regulatable endothelial expression of constitutively active Notch4 (Notch4*tetEC) from birth induced bAVMs in 100% of mice by P16. To test whether targeting downstream signaling, while sustaining the causal Notch4*tetEC expression, induces AVM normalization, we deleted Rbpj, a mediator of Notch signaling, in endothelium from P16, by combining tet-repressible Notch4*tetEC with tamoxifen-inducible Rbpj deletion. Established pathologies, including AV connection diameter, AV shunting, vessel tortuosity, intracerebral hemorrhage, tissue hypoxia, life expectancy, and arterial marker expression were improved, compared with Notch4*tetEC mice without Rbpj deletion. Similarly, Rbpj deletion from P21 induced advanced bAVM regression. After complete AVM normalization induced by repression of Notch4*tetEC, virtually no bAVM relapsed, despite Notch4*tetEC re-expression in adults. Thus, inhibition of endothelial Rbpj halted Notch4*tetEC bAVM progression, normalized bAVM abnormalities, and restored microcirculation, providing proof of concept for targeting a downstream mediator to treat AVM pathologies despite a sustained causal molecular lesion.

We present a case of SCALP syndrome, which was diagnosed in a male infant with the characteristic findings of sebaceous nevi, central nervous system malformations, aplasia cutis congenita, limbal dermoid, and giant congenital melanocytic nevi, or pigmented nevi. We identified a germline compound heterozygous DOCK6 mutation and a somatic mosaic NRAS Q61R mutation in the giant congenital melanocytic nevus. This report will increase clinician awareness of SCALP syndrome and augment the literature in characterizing this rare syndrome, including its genetic background.

Background and Objective: In recent years, studies have been conducted to determine the prevalence rate of congenital abnormalities in different regions of Iran, most of which were conducted on live births. This study was conducted to determine fetal abnormalities in pregnancies leading to legal abortion in Golestan province. Methods: This descriptive-analytical study was conducted on 199 pregnant women with a gestational age of less than 20 weeks with abortion licenses from the Forensic Medicine Center of Golestan province over 9 months during 2018-19. Demographic characteristics, including parents’ age, ethnicity, and family relationship, and the type of fetal abnormalities were recorded. Results: Given 29,460 births in Golestan province over a 9-month period, the prevalence of fetal abnormalities was determined to be 6.75 per thousand births. The incidence rates of fetal abnormalities were determined to be 6.78, 6.68, 7.69, and 5.65 per thousand births in native Fars (80 cases), Turkmen (65 cases), Sistani (34 cases), and other (20 cases) ethnic groups, respectively. Since the gender of 80 fetuses was unknown, the incidence rates of abnormality were determined to be 4.36 and 3.72 per thousand births in female (63 cases) and male (56 cases) fetuses, respectively. The most common fetal abnormalities included central nervous system (n=49, 24.62%), chromosomal abnormalities (n=47, 23.61%), and cardiovascular impairments (n=26, 13.06%). The incidence of fetal abnormalities was not found to have a statistically significant relationship with parents' age, ethnicity, and family relationship. Conclusion: The most prevalent fetal abnormality was related to central nervous system disorders. The incidence of fetal abnormalities had no relationship with the parents’ age, ethnicity, and family relationship.

ObjectiveBCORL1, a transcriptional co-repressor, has a role in cortical migration, neuronal differentiation, maturation, and cerebellar development. We describe BCORL1 as a new genetic cause for major brain malformations.Methods and resultsWe report three patients from two unrelated families with neonatal onset intractable epilepsy and profound global developmental delay. Brain MRI of two siblings from the first family depicted hypoplastic corpus callosum and septal agenesis (ASP) in the older brother and unilateral perisylvian polymicrogyria (PMG) in the younger one. MRI of the patient from the second family demonstrated complete agenesis of corpus callosum (CC). Whole Exome Sequencing revealed a novel hemizygous variant in NM_021946.5 (BCORL1):c.796C>T (p.Pro266Ser) in the two siblings from the first family and the NM_021946.5 (BCORL1): c.3376G>A; p.Asp1126Asn variant in the patient from the second family, both variants inherited from healthy mothers. We reviewed the patients' charts and MRIs and compared the phenotype to the other published BCORL1-related cases. Brain malformations have not been previously described in association with the BCORL1 phenotype. We discuss the potential influence of BCORL1 on brain development.ConclusionsWe suggest that BCORL1 variants present with a spectrum of neurodevelopmental disorders and can lead to major brain malformations originating at different stages of fetal development. We suggest adding BCORL1 to the genetic causes of PMG, ASP, and CC dysgenesis.

ObjectiveTo investigate the relationship between hypotension and neurologic outcome in adults with return of spontaneous circulation after out-of-hospital cardiac arrest.MethodsBlood pressure and medication data were extracted from adult patients who had ROSC after OHCA in Alameda County and matched with neurologic outcome using the CARES database from January 1, 2018 through July 1, 2019. We used univariate logistic regression with p ≤ 0.2 followed by multivariate logistic regression and reported an odds ratio with 95% confidence intervals.ResultsAmong the 781 adult patients who had ROSC after OHCA, 107 (13.7%) were noted to be hypotensive and 61 (57% of the hypotensive group) received vasopressors. Patients with a final prehospital blood pressure recording of

bnormalities in different regions of Iran, most of which were conducted on live births. This study was conducted to determine fetal abnormalities in pregnancies leading to legal abortion in Golestan province. Methods: This descriptive-analytical study was conducted on 199 pregnant women with a gestational age of less than 20 weeks with abortion licenses from the Forensic Medicine Center of Golestan province over 9 months during 2018-19. Demographic characteristics, including parents’ age, ethnicity, and family relationship, and the type of fetal abnormalities were recorded. Results: Given 29,460 births in Golestan province over a 9-month period, the prevalence of fetal abnormalities was determined to be 6.75 per thousand births. The incidence rates of fetal abnormalities were determined to be 6.78, 6.68, 7.69, and 5.65 per thousand births in native Fars (80 cases), Turkmen (65 cases), Sistani (34 cases), and other (20 cases) ethnic groups, respectively. Since the gender of 80 fetuses was unknown, the incidence rates of abnormality were determined to be 4.36 and 3.72 per thousand births in female (63 cases) and male (56 cases) fetuses, respectively. The most common fetal abnormalities included central nervous system (n=49, 24.62%), chromosomal abnormalities (n=47, 23.61%), and cardiovascular impairments (n=26, 13.06%). The incidence of fetal abnormalities was not found to have a statistically significant relationship with parents' age, ethnicity, and family relationship. Conclusion: The most prevalent fetal abnormality was related to central nervous system disorders. The incidence of fetal abnormalities had no relationship with the parents’ age, ethnicity, and family relationship. [ABSTRACT FROM AUTHOR]

BACKGROUND: Seizures are an under-reported feature of the SATB2-associated syndrome phenotype. We describe the electroencephalographic findings and seizure semiology and treatment in a population of individuals with SATB2-associated syndrome. METHODS: We performed a retrospective review of 101 individuals with SATB2-associated syndrome who were reported to have had a previous electroencephalographic study to identify those who had at least one reported abnormal result. For completeness, a supplemental survey was distributed to the caregivers and input from the treating neurologist was obtained whenever possible. RESULTS: Forty-one subjects were identified as having at least one prior abnormal electroencephalography. Thirty-eight individuals (93%) had epileptiform discharges, 28 (74%) with central localization. Sleep stages were included as part of the electroencephalographies performed in 31 individuals (76%), and epileptiform activity was recorded during sleep in all instances (100%). Definite clinical seizures were diagnosed in 17 individuals (42%) with a mean age of onset of 3.2 years (four months to six years), and focal seizures were the most common type of seizure observed (42%). Six subjects with definite clinical seizures needed polytherapy (35%). Delayed myelination and/or abnormal white matter hyperintensities were seen on neuroimaging in 19 individuals (61%). CONCLUSIONS: Epileptiform abnormalities are commonly seen in individuals with SATB2-associated syndrome. A baseline electroencephalography that preferably includes sleep stages is recommended during the initial evaluation of all individuals with SATB2-associated syndrome, regardless of clinical suspicion of epilepsy.

The RNA exosome is an essential ribonuclease complex required for processing and/or degradation of both coding and non-coding RNAs. We identified five patients with biallelic variants in EXOSC5, which encodes a structural subunit of the RNA exosome. The clinical features of these patients include failure to thrive, short stature, feeding difficulties, developmental delays that affect motor skills, hypotonia and esotropia. Brain MRI revealed cerebellar hypoplasia and ventriculomegaly. While we ascertained five patients, three patients with distinct variants of EXOSC5 were studied in detail. The first patient had a deletion involving exons 5-6 of EXOSC5 and a missense variant, p.Thr114Ile, that were inherited in trans, the second patient was homozygous for p.Leu206His and the third patient had paternal isodisomy for chromosome 19 and was homozygous for p.Met148Thr. The additional two patients ascertained are siblings who had an early frameshift mutation in EXOSC5 and the p.Thr114Ile missense variant that were inherited in trans. We employed three complementary approaches to explore the requirement for EXOSC5 in brain development and assess consequences of pathogenic EXOSC5 variants. Loss of function for exosc5 in zebrafish results in shortened and curved tails/bodies, reduced eye/head size and edema. We modeled pathogenic EXOSC5 variants in both budding yeast and mammalian cells. Some of these variants cause defects in RNA exosome function as well as altered interactions with other RNA exosome subunits. These findings expand the number of genes encoding RNA exosome subunits linked to human disease while also suggesting that disease mechanism varies depending on the specific pathogenic variant.

An inherited neurologic syndrome in a family of mixed-breed Oriental cats has been characterized as forebrain commissural malformation, concurrent with ventriculomegaly and interhemispheric cysts. However, the genetic basis for this autosomal recessive syndrome in cats is unknown. Forty-three cats were genotyped on the Illumina Infinium Feline 63K iSelect DNA Array and used for analyses. Genome-wide association studies, including a sib-transmission disequilibrium test and a case-control association analysis, and homozygosity mapping, identified a critical region on cat chromosome A3. Short-read whole genome sequencing was completed for a cat trio segregating with the syndrome. A homozygous 7 bp deletion in growth differentiation factor 7 (GDF7) (c.221_227delGCCGCGC [p.Arg74Profs]) was identified in affected cats, by comparison to the 99 Lives Cat variant dataset, validated using Sanger sequencing and genotyped by fragment analyses. This variant was not identified in 192 unaffected cats in the 99 Lives dataset. The variant segregated concordantly in an extended pedigree. In mice, GDF7 mRNA is expressed within the roof plate when commissural axons initiate ventrally-directed growth. This finding emphasized the importance of GDF7 in the neurodevelopmental process in the mammalian brain. A genetic test can be developed for use by cat breeders to eradicate this variant.

EIF2AK1 and EIF2AK2 encode members of the eukaryotic translation initiation factor 2 alpha kinase (EIF2AK) family that inhibits protein synthesis in response to physiologic stress conditions. EIF2AK2 is also involved in innate immune response and the regulation of signal transduction, apoptosis, cell proliferation, and differentiation. Despite these findings, human disorders associated with deleterious variants in EIF2AK1 and EIF2AK2 have not been reported. Here, we describe the identification of nine unrelated individuals with heterozygous de novo missense variants in EIF2AK1 (1/9) or EIF2AK2 (8/9). Features seen in these nine individuals include white matter alterations (9/9), developmental delay (9/9), impaired language (9/9), cognitive impairment (8/9), ataxia (6/9), dysarthria in probands with verbal ability (6/9), hypotonia (7/9), hypertonia (6/9), and involuntary movements (3/9). Individuals with EIF2AK2 variants also exhibit neurological regression in the setting of febrile illness or infection. We use mammalian cell lines and proband-derived fibroblasts to further confirm the pathogenicity of variants in these genes and found reduced kinase activity. EIF2AKs phosphorylate eukaryotic translation initiation factor 2 subunit 1 (EIF2S1, also known as EIF2α), which then inhibits EIF2B activity. Deleterious variants in genes encoding EIF2B proteins cause childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM), a leukodystrophy characterized by neurologic regression in the setting of febrile illness and other stressors. Our findings indicate that EIF2AK2 missense variants cause a neurodevelopmental syndrome that may share phenotypic and pathogenic mechanisms with CACH/VWM.

Abstract Aicardi-Goutières syndrome (AGS) is a rare genetic disorder involving the central nervous system and autoimmune abnormalities, leading to severe intellectual and physical disability with poor prognosis. AGS has a phenotype similar to intrauterine viral infection, which often leads to delays in genetic counseling. In this study, we report a case with a prenatal diagnosis of AGS. The first fetal ultrasound detected bilateral lateral ventricle cystic structures, and fetal MRI was performed to identify other signs. The right parietal lobe signal showed cerebral white matter abnormalities, and fetal brain development level was lower than that of normal fetuses of the same gestational age. Whole-exome sequencing revealed that the fetus carried the TREX1:NM_033629.6:exon2:c.294dup:p. C99Mfs*3 variant, suggesting that the c.294dup mutation of the TREX1 gene was the pathogenic mutation site, and the final comprehensive diagnosis was AGS1. In this article, we also reviewed the previous literature for possible phenotypes in the fetus and found that microcephaly and intrauterine growth retardation may be the first and most important markers of the intrauterine phenotype of AGS.

WD40 repeat-containing proteins form a large family of proteins present in all eukaryotes. Here, we identified five pediatric probands with de novo variants in WDR37, which encodes a member of the WD40 repeat protein family. Two probands shared one variant and the others have variants in nearby amino acids outside the WD40 repeats. The probands exhibited shared phenotypes of epilepsy, colobomas, facial dysmorphology reminiscent of CHARGE syndrome, developmental delay and intellectual disability, and cerebellar hypoplasia. The WDR37 protein is highly conserved in vertebrate and invertebrate model organisms and is currently not associated with a human disease. We generated a null allele of the single Drosophila ortholog to gain functional insights and replaced the coding region of the fly gene CG12333/wdr37 with GAL4. These flies are homozygous viable but display severe bang sensitivity, a phenotype associated with seizures in flies. Additionally, the mutant flies fall when climbing the walls of the vials, suggesting a defect in grip strength, and repeat the cycle of climbing and falling. Similar to wall clinging defect, mutant males often lose grip of the female abdomen during copulation. These phenotypes are rescued by using the GAL4 in the CG12333/wdr37 locus to drive the UAS-human reference WDR37 cDNA. The two variants found in three human subjects failed to rescue these phenotypes, suggesting that these alleles severely affect the function of this protein. Taken together, our data suggest that variants in WDR37 underlie a novel syndromic neurological disorder.

Aicardi-Goutières syndrome (AGS) is a rare genetic disorder involving the central nervous system and autoimmune abnormalities, leading to severe intellectual and physical disability with poor prognosis. AGS has a phenotype similar to intrauterine viral infection, which often leads to delays in genetic counseling. In this study, we report a case with a prenatal diagnosis of AGS. The first fetal ultrasound detected bilateral lateral ventricle cystic structures, and fetal MRI was performed to identify other signs. The right parietal lobe signal showed cerebral white matter abnormalities, and fetal brain development level was lower than that of normal fetuses of the same gestational age. Whole-exome sequencing revealed that the fetus carried the TREX1:NM_033629.6:exon2:c.294dup:p. C99Mfs*3 variant, suggesting that the c.294dup mutation of the TREX1 gene was the pathogenic mutation site, and the final comprehensive diagnosis was AGS1. In this article, we also reviewed the previous literature for possible phenotypes in the fetus and found that microcephaly and intrauterine growth retardation may be the first and most important markers of the intrauterine phenotype of AGS. [ABSTRACT FROM AUTHOR]

Corpus callosum malformations are associated with a broad range of neurodevelopmental diseases. We report that de novo mutations in MAST1 cause mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations (MCC-CH-CM) in the absence of megalencephaly. We show that MAST1 is a microtubule-associated protein that is predominantly expressed in post-mitotic neurons and is present in both dendritic and axonal compartments. We further show that Mast1 null animals are phenotypically normal, whereas the deletion of a single amino acid (L278del) recapitulates the distinct neurological phenotype observed in patients. In animals harboring Mast1 microdeletions, we find that the PI3K/AKT3/mTOR pathway is unperturbed, whereas Mast2 and Mast3 levels are diminished, indicative of a dominant-negative mode of action. Finally, we report that de novo MAST1 substitutions are present in patients with autism and microcephaly, raising the prospect that mutations in this gene give rise to a spectrum of neurodevelopmental diseases.

Inherited GPI deficiencies (IGDs) are a subset of congenital disorders of glycosylation that are increasingly recognized as a result of advances in whole-exome sequencing (WES) and whole-genome sequencing (WGS). IGDs cause a series of overlapping phenotypes consisting of seizures, dysmorphic features, multiple congenital malformations, and severe intellectual disability. We present a study of six individuals from three unrelated families in which WES or WGS identified bi-allelic phosphatidylinositol glycan class S (PIGS) biosynthesis mutations. Phenotypes included severe global developmental delay, seizures (partly responding to pyridoxine), hypotonia, weakness, ataxia, and dysmorphic facial features. Two of them had compound-heterozygous variants c.108G>A (p.Trp36∗) and c.101T>C (p.Leu34Pro), and two siblings of another family were homozygous for a deletion and insertion leading to p.Thr439_Lys451delinsArgLeuLeu. The third family had two fetuses with multiple joint contractures consistent with fetal akinesia. They were compound heterozygous for c.923A>G (p.Glu308Gly) and c.468+1G>C, a splicing mutation. Flow-cytometry analyses demonstrated that the individuals with PIGS mutations show a GPI-AP deficiency profile. Expression of the p.Trp36∗ variant in PIGS-deficient HEK293 cells revealed only partial restoration of cell-surface GPI-APs. In terms of both biochemistry and phenotype, loss of function of PIGS shares features with PIGT deficiency and other IGDs. This study contributes to the understanding of the GPI-AP biosynthesis pathway by describing the consequences of PIGS disruption in humans and extending the family of IGDs.

During its most recent outbreak across the Americas, Zika virus (ZIKV) was surprisingly shown to cause fetal loss and congenital malformations in acutely and chronically infected pregnant women. However, understanding the underlying pathogenesis of ZIKV congenital disease has been hampered by a lack of relevant in vivo experimental models. Here we present a candidate New World monkey model of ZIKV infection in pregnant marmosets that faithfully recapitulates human disease. ZIKV inoculation at the human-equivalent of early gestation caused an asymptomatic seroconversion, induction of type I/II interferon-associated genes and proinflammatory cytokines, and persistent viremia and viruria. Spontaneous pregnancy loss was observed 16-18 days post-infection, with extensive active placental viral replication and fetal neurocellular disorganization similar to that seen in humans. These findings underscore the key role of the placenta as a conduit for fetal infection, and demonstrate the utility of marmosets as a highly relevant model for studying congenital ZIKV disease and pregnancy loss.

C57BL/6 mice exhibit spontaneous cerebellar malformations consisting of heterotopic neurons and glia in the molecular layer of the posterior vermis, indicative of neuronal migration defect during cerebellar development. Recognizing that many genetically engineered (GE) mouse lines are produced from C57BL/6 ES cells or backcrossed to this strain, we performed histological analyses and found that cerebellar heterotopia were a common feature present in the majority of GE lines on this background. Furthermore, we identify GE mouse lines that will be valuable in the study of cerebellar malformations including diverse driver, reporter, and optogenetic lines. Finally, we discuss the implications that these data have on the use of C57BL/6 mice and GE mice on this background in studies of cerebellar development or as models of disease.

This study aimed to analyze, in the São Paulo state of Brazil, time trends in prevalence, neonatal mortality, and neonatal lethality of central nervous system congenital malformations (CNS-CM) between 2004 and 2015. Population-based study of all live births with gestational age ≥22 weeks and/or birthweight ≥400 g from mothers living in São Paulo State, during 2004–2015. CNS-CM was defined by the presence of International Classification Disease 10th edition codes Q00–Q07 in the death and/or live birth certificates. CNS-CM was classified as isolated (only Q00–Q07 codes), and non-isolated (with congenital anomalies codes nonrelated to CNS-CM). CNS-CM associated neonatal death was defined as death between 0 and 27 days after birth in infants with CNS-CM. CNS-CM prevalence, neonatal mortality, and lethality rates were calculated, and their annual trends were analyzed by Prais-Winsten Model. The annual percent change (APC) with 95% confidence interval (95%CI) was obtained. 7,237,628 live births were included in the study and CNS-CM were reported in 7526 (0.1%). CNS-CM associated neonatal deaths occurred in 2935 (39.0%). Isolated CNS-CM and non-isolated CNS-CM were found respectively in 5475 and 2051 livebirths, with 1525 (28%) and 1410 (69%) neonatal deaths. CNS-CM prevalence and neonatal lethality were stationary, however neonatal mortality decreased (APC −1.66; 95%CI −3.09 to −0.21) during the study. For isolated CNS-CM, prevalence, neonatal mortality, and lethality decreased over the period. For non-isolated CNS-CM, the prevalence increased, neonatal mortality was stationary, and lethality decreased during the period. The median time of CNS-CM associated neonatal deaths was 18 h after birth. During a 12-year period in São Paulo State, Brazil, neonatal mortality of infants with CNS-CM in general and with isolated CNS-CM showed a decreasing pattern. Nevertheless CNS-CM mortality remained elevated, mostly in the first day after birth. [ABSTRACT FROM AUTHOR]

CEP55 encodes centrosomal protein 55 kDa, which plays a crucial role in mitosis, particularly cytokinesis. Biallelic CEP55 variants cause MARCH syndrome (multinucleated neurons, anhydramnios, renal dysplasia, cerebellar hypoplasia and hydranencephaly). Here, we describe a Japanese family with two affected siblings harboring novel compound heterozygous CEP55 variants, NM_001127182: c.[1357 C > T];[1358 G > A] p.[(Arg453Cys)];[(Arg453His)]. Both presented clinically with typical lethal MARCH syndrome. Although a combination of missense and nonsense variants has been reported previously, this is the first report of biallelic missense CEP55 variants. These variants biallelically affected the same amino acid, Arg453, in the last 40 amino acids of CEP55. These residues are functionally important for CEP55 localization to the midbody during cell division, and may be associated with severe clinical outcomes. More cases of pathogenic CEP55 variants are needed to establish the genotype-phenotype correlation., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to The Japan Society of Human Genetics.)

CASK (MIM#300172), encoding a calcium/calmodulin-dependent serine protein kinase, is crucial for synaptic transmission and gene regulation during neural development. Pathogenic variants of CASK are known to cause several neurodevelopmental disorders, including X-linked intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH). This study introduces a novel, de novo synonymous CASK variant (NM_001367721.1: c.1737G>A, p.(Glu579=)), discovered in a male patient diagnosed with MICPCH, characterized by microcephaly, developmental delay, visual impairment, and myoclonic seizures. The variant disrupts a donor splice-site at the end of exon 18. Transcriptomic analysis of blood identified 12 different CASK transcripts secondary to the synonymous variant. Nearly one third of these transcripts were predicted to result in nonsense mediated decay or protein degradation. Protein modeling revealed structural alterations in the PDZ functional domain of CASK, due to exon 18 deletion. Our findings highlight the utility of transcriptomic analysis in demonstrating the underlying disease mechanism in neurodevelopmental disorders., (© 2024 The Author(s). Clinical Genetics published by John Wiley & Sons Ltd.)