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Objectives: Children with microcephaly exhibit neurodevelopmental delays and compromised communicative functioning, yielding challenges for clinical assessment and informed intervention. This study characterized auditory neural function and communication abilities in children with microcephaly due to congenital Zika syndrome (CZS)., Design: Click-evoked auditory brainstem responses (ABR) at fast and slow stimulation rates and natural speech-evoked cortical auditory evoked potentials (CAEP) were recorded in 25 Brazilian children with microcephaly related to CZS ( M age: 5.93 ± 0.62 years) and a comparison group of 25 healthy children ( M age: 5.59 ± 0.80 years) matched on age, sex, ethnicity, and socioeconomic status. Communication abilities in daily life were evaluated using caregiver reports on Vineland Adaptive Behavior Scales-3., Results: Caregivers of children with microcephaly reported significantly lower than typical adaptive functioning in the communication and socialization domains. ABR wave I latency did not differ significantly between the groups, suggesting comparable peripheral auditory function. ABR wave V absolute latency and waves I-V interwave latency were significantly shorter in the microcephaly group for both ears and rates. CAEP analyses identified reduced N2 amplitudes in children with microcephaly as well as limited evidence of speech sound differentiation, evidenced mainly by the N2 response latency. Conversely, in the comparison group, speech sound differences were observed for both the P1 and N2 latencies. Exploratory analyses in the microcephaly group indicated that more adaptive communication was associated with greater speech sound differences in the P1 and N2 amplitudes. The trimester of virus exposure did not have an effect on the ABRs or CAEPs., Conclusions: Microcephaly related to CZS is associated with alterations in subcortical and cortical auditory neural function. Reduced ABR latencies differ from previous reports, possibly due to the older age of this cohort and careful assessment of peripheral auditory function. Cortical speech sound detection and differentiation are present but reduced in children with microcephaly. Associations between communication performance in daily life and CAEPs highlight the value of auditory evoked potentials in assessing clinical populations with significant neurodevelopmental disabilities., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: This study aimed to identify continuous epileptiform discharges (CEDs) on electroencephalograms (EEG) and to determine their clinical significance in children with congenital Zika syndrome (CZS)., Methods: This prospective cohort study included 75 children diagnosed with CZS born from March 2015 and followed up until September 2018 (age up to 36 months). EEG was performed to detect CEDs up to 24 months old. Data on obstetric, demographic, and clinical signs; cranial computed tomography (CT); ophthalmology examination; anti-seizure medication; growth; and motor development were collected. Fisher's exact test was used to verify the associations between categorical variables, and the T- test was used to compare the mean z-scores of anthropometric measurements between the groups with and without CED., Results: CEDs were identified in 41 (54.67 %) children. The mean age of CEDs identification was 12.24 ± 6.86 months. Bilateral CEDs were shown in 62.89 % of EEGs. CEDs were associated with severe congenital microcephaly, defined by z-score >3 standard deviation of head circumference (HC) below the mean for sex and age (p = 0.025), and worse outcomes, including first seizure before 6 months (p = 0.004), drug-resistant epilepsy (p < 0.001), chorioretinal scarring or mottling (p = 0.002), and severe CT findings (p = 0.002). The CED group had lower mean z-scores of HC up to 24 months of age., Conclusion: This is the first description of the prevalence and significance of CEDs that also remains during wakefulness in patients with CZS. New investigations may suggest that it is more appropriate to classify the EEG not as a CED, but as a periodic pattern. Anyway, CEDs may be a marker of neurological severity in children with CSZ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Objective: To assess the longitudinal evolution of EEG findings in children with Zika related-microcephaly (ZRM) and to evaluate the associations of these patterns with the children's clinical and neuroimaging characteristics., Methods: As part of the follow-up of the Microcephaly Epidemic Research Group Pediatric Cohort (MERG-PC) in Recife, Brazil, we performed serial EEG recordings in a subgroup of children with ZRM to evaluate changes in background rhythms and epileptiform activity (EA). Latent class analysis was used to identify patterns in the evolution of EA over time; clinical and neuroimaging findings were compared across the identified groups., Results: Out of the 72 children with ZRM who were evaluated during 190 EEGs/videoEEGs, all participants presented with abnormal background activity, 37.5% presented with an alpha-theta rhythmic activity, and 25% presented with sleep spindles, which were less commonly observed in children with epilepsy. EA changed over time in 79.2% of children, and three distinct trajectories were identified: (i) multifocal EA over time, (ii) no discharges/focal EA evolving to focal/multifocal EA, and (iii) focal/multifocal EA evolving to epileptic encephalopathy patterns (e.g., hypsarrhythmia or continuous EA in sleep). The multifocal EA over time trajectory was associated with periventricular and thalamus/basal ganglia calcifications, brainstem and corpus callosum atrophy and had less focal epilepsy, whereas the children in the trajectory which evolved to epileptic encephalopathy patterns had more frequently focal epilepsy., Significance: These findings suggest that, in most children with ZRM, trajectories of changes in EA can be identified and associated with neuroimaging and clinical features., Competing Interests: Declaration of Competing Interest None of the authors has any conflicts of interest to disclose., (Copyright © 2023. Published by Elsevier Ltd.)

RBL2/p130, a member of the retinoblastoma family of proteins, is a key regulator of cell division and propagates irreversible senescence. RBL2/p130 is also involved in neuronal differentiation and survival, and eliminating Rbl2 in certain mouse strains leads to embryonic lethality accompanied by an abnormal central nervous system (CNS) phenotype. Conflicting reports exist regarding a role of RBL2/p130 in transcriptional regulation of DNA methyltransferases (DNMTs), as well as the control of telomere length. Here we describe the phenotype of three patients carrying bi-allelic RBL2-truncating variants. All presented with infantile hypotonia, severe developmental delay and microcephaly. Malignancies were not reported in carriers or patients. Previous studies carried out on mice and human cultured cells, associated RBL2 loss to DNA methylation and telomere length dysregulation. Here, we investigated whether patient cells lacking RBL2 display related abnormalities. The study of primary patient fibroblasts did not detect abnormalities in expression of DNMTs. Furthermore, methylation levels of whole genome DNA, and specifically of pericentromeric repeats and subtelomeric regions, were unperturbed. RBL2-null fibroblasts show no evidence for abnormal elongation by telomeric recombination. Finally, gradual telomere shortening, and normal onset of senescence were observed following continuous culturing of RBL2-mutated fibroblasts. Thus, this study resolves uncertainties regarding a potential non-redundant role for RBL2 in DNA methylation and telomere length regulation, and indicates that loss of function variants in RBL2 cause a severe autosomal recessive neurodevelopmental disorder in humans., (© 2021. The Author(s), under exclusive licence to The Japan Society of Human Genetics.)

Congenital Zika Syndrome (CZS) is characterized by changes in cranial morphology associated with heterogeneous neurological manifestations and cognitive and behavioral impairments. In this syndrome, longitudinal neuroimaging could help clinicians to predict developmental trajectories of children and tailor treatment plans accordingly. However, regularly acquiring magnetic resonance imaging (MRI) has several shortcomings besides cost, particularly those associated with childrens' clinical presentation as sensitivity to environmental stimuli. The indirect monitoring of local neural activity by non-invasive functional near-infrared spectroscopy (fNIRS) technique can be a useful alternative for longitudinally accessing the brain function in children with CZS. In order to provide a common framework for advancing longitudinal neuroimaging assessment, we propose a principled guideline for fNIRS acquisition and analyses in children with neurodevelopmental disorders. Based on our experience on collecting fNIRS data in children with CZS we emphasize the methodological challenges, such as clinical characteristics of the sample, desensitization, movement artifacts and environment control, as well as suggestions for tackling such challenges. Finally, metrics based on fNIRS can be associated with established clinical metrics, thereby opening possibilities for exploring this tool as a long-term predictor when assessing the effectiveness of treatments aimed at children with severe neurodevelopmental disorders., (© 2021. The Author(s).)

Normal neurodevelopment relies on intricate signaling pathways that balance neural stem cell (NSC) self-renewal, maturation, and survival. Disruptions lead to neurodevelopmental disorders, including microcephaly. Here, we implicate the inhibition of NSC senescence as a mechanism underlying neurogenesis and corticogenesis. We report that the receptor for activated C kinase (Rack1), a family member of WD40-repeat (WDR) proteins, is highly enriched in NSCs. Deletion of Rack1 in developing cortical progenitors leads to a microcephaly phenotype. Strikingly, the absence of Rack1 decreases neurogenesis and promotes a cellular senescence phenotype in NSCs. Mechanistically, the senescence-related p21 signaling pathway is dramatically activated in Rack1 null NSCs, and removal of p21 significantly rescues the Rack1-knockout phenotype in vivo. Finally, Rack1 directly interacts with Smad3 to suppress the activation of transforming growth factor (TGF)-β/Smad signaling pathway, which plays a critical role in p21-mediated senescence. Our data implicate Rack1-driven inhibition of p21-induced NSC senescence as a critical mechanism behind normal cortical development., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Distal 1q21.1 microdeletions have shown highly variable clinical expressivity and incomplete penetrance, with affected individuals manifesting a broad spectrum of nonspecific features. The goals of this study were to better describe the phenotypic spectrum of patients with distal 1q21.1 microdeletions and to compare the clinical features among affected individuals. We performed a retrospective chart review of 47 individuals with distal 1q21.1 microdeletions tested at a large clinical genetic testing laboratory, with most patients being clinically evaluated in the same children's hospital. Health information such as growth charts, results of imaging studies, developmental history, and progress notes were collected. Statistical analysis was performed using Fisher's exact test to compare clinical features among study subjects. Common features in our cohort include microcephaly (51.2%), seizures (29.8%), developmental delay (74.5%), failure to thrive (FTT) (68.1%), dysmorphic features (63.8%), and a variety of congenital anomalies such as cardiac abnormalities (23.4%) and genitourinary abnormalities (19.1%). Compared to prior literature, we found that seizures, brain anomalies, and FTT were more prevalent among our study cohort. Females were more likely than males to have microcephaly (p = 0.0199) and cardiac abnormalities (p = 0.0018). Based on existing genome-wide clinical testing results, at least a quarter of the cohort had additional genetic findings that may impact the phenotype of the individual. Our study represents the largest cohort of distal 1q21.1 microdeletion carriers available in the literature thus far, and it further illustrates the wide spectrum of clinical manifestations among symptomatic individuals. These results may allow for improved genetic counseling and management of affected individuals. Future studies may help to elucidate the underlying molecular mechanisms impacting the phenotypic variability observed with this microdeletion., (© 2021 Wiley Periodicals LLC.)

Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL), defined primarily by developmental delay/intellectual disability, speech delay, postnatal microcephaly, and dysmorphic features, is a syndrome resulting from heterozygous variants in the dosage-sensitive bromodomain PHD finger chromatin remodeler transcription factor BPTF gene. To date, only 11 individuals with NEDDFL due to de novo BPTF variants have been described. To expand the NEDDFL phenotypic spectrum, we describe the clinical features in 25 novel individuals with 20 distinct, clinically relevant variants in BPTF, including four individuals with inherited changes in BPTF. In addition to the previously described features, individuals in this cohort exhibited mild brain abnormalities, seizures, scoliosis, and a variety of ophthalmologic complications. These results further support the broad and multi-faceted complications due to haploinsufficiency of BPTF., (© 2021 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)

Genetic studies identified multiple mutations associated with malformations of cortical development (MCD) in humans. When analyzing the underlying mechanisms in non-human experimental models it became increasingly evident, that these mutations accumulate in genes, which functions evolutionary progressed from rodents to humans resulting in an incomplete reflection of the molecular and cellular alterations in these models. Human brain organoids derived from human pluripotent stem cells resemble early aspects of human brain development to a remarkable extent making them an attractive model to investigate MCD. Here we review how human brain organoids enable the generation of fundamental new insight about the underlying pathomechanisms of MCD. We show how phenotypic features of these diseases are reflected in human brain organoids and discuss challenges and future considerations but also limitations for the use of human brain organoids to model human brain development and associated disorders., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Microcephaly and macrocephaly can be considered both cranial growth defects and clinical symptoms. There are two assessment criteria: one applied in dysmorphology and another conventionally used in clinical practice. The determination of which definition or under which paradigm the terminology should be applied can vary on a daily basis and from case to case as necessity dictates, as can defining the relationship between microcephaly or macrocephaly and syndromes or diseases associated with neurodysfunction. Thus, there is a need for standardization of the definition of microcephaly and macrocephaly. This study was designed to investigate associations between abnormal cranial development (head size) and diseases or syndromes linked to neurodysfunction based on essential data collected upon admission of patients to the Neurological Rehabilitation Ward for Children and Adolescents in Poland. The retrospective analysis involved 327 children and adolescents with medical conditions associated with neurodysfunction. Two assessment criteria were applied to identify subgroups of patients with microcephaly, normal head size, and macrocephaly: one system commonly used in clinical practice and another applied in dysmorphology. Based on the results, children and adolescents with syndromes or diseases associated with neurodysfunction present abnormal cranial development (head size), and microcephaly rarely co-occurs with neuromuscular disease. Macrocephaly frequently co-occurs with neural tube defects or neuromuscular diseases and rarely with cerebral palsy (p < 0.05); microcephaly frequently co-occurs with epilepsy and hypothyroidism (p < 0.001). Traditional classification facilitates the identification of a greater number of relationships and is therefore recommended for use in daily practice. There is a need to standardize the definition of microcephaly and macrocephaly and to include them in 'Human Phenotype Ontology' terms.

Background: Little information on gross motor function of congenital Zika syndrome (CZS) children is available., Objectives: To evaluate gross motor function in CZS children aged up to 3 years, and its associated factors and changes in a minimum interval of 6 months., Methods: One hundred children with CZS and cerebral palsy (36 with confirmed and 64 with presumed CZS) were evaluated with the Gross Motor Function Classification System (GMFCS) and Gross Motor Function Measure (GMFM-88/GMFM-66). Forty-six were reevaluated. Wilcoxon tests, Wilcoxon tests for paired samples, percentile scores, and score changes were performed., Results: Clinical and socioeconomic characteristics (except maternal age), GMFM scores and GMFCS classification of confirmed and probable cases, which were analyzed together, were similar. The mean age was 25.6 months (±5.5); the median GMFM-88 score was 8.0 (5.4-10.8); and the median GMFM-66 score was 20.5 (14.8-23.1); 89% were classified as GMFCS level V. Low economic class, microcephaly at birth, epilepsy, and brain parenchymal volume loss were associated with low GMFM-66 scores. The median GMFM-66 percentile score was 40 (20-55). On the second assessment, the GMFM-66 scores in two GMFCS level I children and one GMFCS level IV child improved significantly. In one GMFCS level III child, one GMFCS level IV child, and the group of GMFCS level V children, no significant changes were observed., Conclusions: Almost all CZS children had severe cerebral palsy; in the third year of life, most presented no improvement in gross motor function and were likely approaching their maximal gross motor function potential., Competing Interests: Dr. Souza reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Simoes reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Gomes reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Ribeiro reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Amaral reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Sousa reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Takahasi reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Borges reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Alves reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Khouri reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study.Dr. Silva reports grants from Brazilian National Council for Scientific and Technological Development (CNPq), State Funding Agency of Maranhao (FAPEMA), Ministry of Health Department of Science and Technology (DECIT), and the Ministry of Education Coordination for the Improvement of Higher Education (CAPES), during the conduct of the study., (Thieme. All rights reserved.)

The phosphatidylinositol glycan anchor biosynthesis class S protein (PIGS) gene has recently been implicated in a novel congenital disorder of glycosylation resulting in autosomal recessive inherited glycosylphosphatidylinositol-anchored protein (GPI-AP) deficiency. Previous studies described seven patients with biallelic variants in the PIGS gene, of whom two presented with fetal akinesia and five with global developmental delay and epileptic developmental encephalopathy. We present the molecular and clinical characteristics of six additional individuals from five families with unreported variants in PIGS. All individuals presented with hypotonia, severe global developmental delay, microcephaly, intractable early infantile epilepsy, and structural brain abnormalities. Additional findings include vision impairment, hearing loss, renal malformation, and hypotonic facial appearances with minor dysmorphic features but without a distinctive facial gestalt. Four individuals died due to neurologic complications. GPI anchoring studies performed on one individual revealed a significant decrease in GPI-APs. We confirm that biallelic variants in PIGS cause vitamin pyridoxine-responsive epilepsy due to inherited GPI deficiency and expand the genotype and phenotype of PIGS-related disorder. Further delineation of the molecular spectrum of PIGS-related disorders would improve management, help develop treatments, and encourage the expansion of diagnostic genetic testing to include this gene as a potential cause of neurodevelopmental disorders and epilepsy., (© 2021 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Congenital Zika syndrome (CZS) constitutes a recently identified malformation caused by Zika virus infection during pregnancy. Limited data is available to date on the facial dysmorphic features of these patients. This study evaluated the facial dysmorphisms of children with CZS, compared with clinically healthy children, using clinical examination and standardized photographic images. Sixty-three children with CZS (9.70 ± 3.2 months-age), and 31 Controls (8.67 ± 6.2 months-age) joined the study. Seven out of 15 indices differed between groups: midfacial height (MFH)/horizontal facial reference (HFR) (p = .0003), interalar distance/HFR (p = .0027), nasal root depth/MFH (p = .0030), posterior nasal length/MFH (p = .0002), vertical position of the ear/MFH (p <.0001), ear length/MFH (p = .0005), chin height/total facial height (CH/TFH) (p <.0001). A CH/TFH of 0.229 showed 93.9% sensitivity and 80.6% specificity in diagnosing CZS. Children with CZS had broad, short faces, decreased intercanthal distance, short posterior nasal length, prominent nasal root, broad nasal wings, and high-set and long ears. Increased chin height index provided the most accurate diagnostic potential., (© 2020 Wiley Periodicals LLC.)

Purpose: The purpose of this study was to analyze the natural history and phenotypic overlap of patients with microcephaly and a chorioretinopathy or familial exudative vitreoretinopathy (FEVR) ocular phenotype caused by mutations in KIF11, TUBGCP4, or TUBGCP6., Methods: Patients diagnosed with congenital microcephaly and chorioretinopathy or FEVR were included. Molecular investigations consisted of targeted genetic sequencing. Data from medical records, ophthalmologic examination and imaging, electroretinography, and visual fields were analyzed for systemic and ophthalmic features and evidence of posterior segment disease progression., Results: Twelve patients from 9 families were included and had a median of 8 years of follow-up. Nine patients had KIF11 variants, two had heterozygous TUBGCP6 variants, and one had heterozygous variants in TUBGCP4. All patients had reduced visual function and multiple individuals and families showed features of both chorioretinopathy and FEVR. Progression of posterior segment disease was highly variable, with some degree of increased atrophy of the macula or peripheral retina or increased vitreoretinal traction observed in 9 of 12 patients., Conclusions: Microcephaly due to mutations in KIF11, TUBGCP4, or TUBGCP6 can be associated with retinal disease on a spectrum from chorioretinal atrophy to FEVR-like posterior segment changes. Visually significant disease progression can occur and patients should be monitored closely by a team experienced in ophthalmic genetics.

Aim of the Study: Mowat Wilson syndrome (MWS) is a complex genetic disorder due to mutation or deletion of the ZEB2 gene (ZFHX1B), including multiple clinical features. Hirschsprung disease is associated with this syndrome with a prevalence between 43 and 57%. The aim of this study was to demonstrate the severe outcomes and the high complication rates in children with MWS, focusing on their complicated follow-up., Methods: A retrospective comparative study was conducted on patients referred to Robert-Debré Children's Hospital for MWS from 2003 to 2018. Multidisciplinary follow-up was carried out by surgeons, geneticists, gastroenterologists, and neurologists. Data regarding patient characteristics, surgical management, postoperative complications, and functional outcomes were collected., Results: Over this period of 15 years, 23 patients were diagnosed with MWS. Hirschsprung disease was associated with 10 of them (43%). Of these cases, two patients had recto-sigmoïd aganglionosis (20%), three had aganglionic segment extension to the left colic angle (30%), two to the right colic angle (20%), and three to the whole colon (30%). The median follow-up was 8.5 years (2 months-15 years). All patients had seizures and intellectual disability. Six children (60%) presented with cardiac defects. At the last follow-up, three patients still had a stoma diversion and 7 (70%) were fed orally. One patient died during the first months. Eight (80%) of these children required a second surgery due to complications. At the last follow-up, three patients reported episodes of abdominal bloating (42%), one recurrent treated constipation (14.3%), and one soiling (14.3%). Genetic analysis identified three patients with heterozygous deletions, three with codon mutations, and three with frameshift mutations., Conclusions: MWS associated with Hirschsprung disease has a high rate of immediate surgical complications but some patients may achieve bowel function comparable with non-syndromic HD patients. A multidisciplinary follow-up is required for these patients., Level of Evidence: Retrospective observational single cohort study, Level 3.

Objectives: This study aimed to describe the demographic and clinical parameters of women infected by Zika virus who had infants with stigmata of Congenital Zika Syndrome (CZS) versus those who had normal-appearing infants at birth, thereby providing further details on the clinical caveats of neonatal ZIKV infection., Methodology: This cross-sectional study was performed in the state of Mato Grosso do Sul, Central-West region of Brazil, and included 117 mother-infant pairs who were interviewed and 120 gestational outcomes. All mothers had laboratory confirmation by qRT-PCR of ZIKV infection during pregnancy., Results: The prevalence of congenital abnormalities related to ZIKV was 2.69 cases per 10,000 live births during this period. Exanthem was the main clinical finding, observed in 92.5% of the mothers in this study. Regarding the timing of ZIKV infection, the first trimester was the most frequent time of infection among mothers of infants with CZS (54.55%) (p=0.0007). The case fatality rate was 5% (n=6). Among the 23 children who were classified as having CZS, 13 (56.52%) of them presented with microcephaly. Only 13 (56.52%) children with CZS were tested by qRT-PCR for ZIKV infection at birth, five (38%) were positive., Conclusions: This study highlights the congenital alterations of ZIKV infection during pregnancy in an epidemic burst, demonstrating that the alterations found in other studies are similar to the present research., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Mitochondrial complex I deficiency is caused by pathogenic variants in mitochondrial and nuclear genes associated with complex I structure and assembly. We report the case of a patient with　NDUFA8-related mitochondrial disease. The patient presented with developmental delay, microcephaly, and epilepsy. His fibroblasts showed apparent biochemical defects in mitochondrial complex I. Whole-exome sequencing revealed that the patient carried a homozygous variant in NDUFA8. His fibroblasts showed a reduction in the protein expression level of not only NDUFA8, but also the other complex I subunits, consistent with assembly defects. The enzyme activity of complex I and oxygen consumption rate were restored by reintroducing wild-typeNDUFA8 cDNA into patient fibroblasts. The functional properties of the variant in NDUFA8 were also investigated using NDUFA8 knockout cells expressing wild-type or mutated NDUFA8 cDNA. These experiments further supported the pathogenicity of the variant in complex I assembly. This is the first report describing that the loss of NDUFA8, which has not previously been associated with mitochondrial disease, causes severe defect in the assembly of mitochondrial complex I, leading to progressive neurological and developmental abnormalities., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Although it is known that Zika virus (ZIKV) infection during pregnancy may lead to microcephaly in the fetus, the prognostic factors associated with this tragic disorder remain unclear. We conducted a systematic review and meta-analysis to assess the prognostic factors associated with the incidence of microcephaly in congenital ZIKV infection., Methods: We conducted a comprehensive search in Ovid MEDLINE, Ovid MEDLINE (R) Epub ahead of print, Embase, Embase Classic, Web of Science, CINAHL, Cochrane CENTRAL, LILACS, and various thesis databases to identify human studies reporting microcephaly associated with congenital ZIKV infection. We requested primary data from the authors of the included studies to calculate summary estimates and conduct the meta-analysis of the most prevalent factors., Results: We screened 4106 titles and abstracts, and identified 12 studies for inclusion in the systematic review. The assessment of ZIKV infection and the definition of microcephaly varied among studies. A total of 6154 newborns/fetuses were enrolled; of those, 1120 (18.20%) had a diagnostic of ZIKV infection, of which 509 (45.45%) were diagnosed with microcephaly. Nine studies addressed the link between congenital ZIKV infection and neurological findings in newborns/fetuses. Half of the studies provided primary data. Three out of 11 factors of interest seem to be prognostic factors of microcephaly: infant's sex - males compared to females: Relative Risk (RR) 1.30, 95% Confidence Interval (95% CI) 1.14 to 1.49; the stage of pregnancy when infection occurred - infection in the first trimester of pregnancy compared to infection at other stages of pregnancy: RR 1.41, 95% CI 1.09 to 1.82; and asymptomatic infection compared to symptomatic infection during pregnancy: RR 0.68; 95% CI 0.60 to 0.77., Conclusion: Our findings support the female-biased resistance hypothesis and reinforce the risk associated with the stage of pregnancy when ZIKV infection occurs. Continued surveillance of ZIKV infection during pregnancy is needed to identify additional factors that could contribute to developing microcephaly in affected fetuses., Protocol Registration: This systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO), registration no. CRD 42018088075.

Significant clinical symptoms of Cohen syndrome (CS), a rare autosomal recessive disorder, include intellectual disability, facial dysmorphism, postnatal microcephaly, retinal dystrophy, and intermittent neutropenia. CS has been associated with mutations in the VPS13B (vacuolar protein sorting 13 homolog B) gene, which regulates vesicle-mediated protein sorting and transport; however, the cellular mechanism underlying CS pathogenesis in patient-derived neurons remains uncertain. This report states that autophagic vacuoles accumulate in CS fibroblasts and the axonal terminals of CS patient-specific induced pluripotent stem cells (CS iPSC)-derived neurons; additionally, autophagic flux was significantly increased in CS-derived neurons compared to control neurons. VPS13B knockout HeLa cell lines generated using the CRISPR/Cas9 genome editing system showed significant upregulation of autophagic flux, indicating that VSP13B may be associated with autophagy in CS. Transcriptomic analysis focusing on the autophagy pathway revealed that genes associated with autophagosome organization were dysregulated in CS-derived neurons. ATG4C is a mammalian ATG4 paralog and a crucial regulatory component of the autophagosome biogenesis/recycling pathway. ATG4C was significantly upregulated in CS-derived neurons, indicating that autophagy is upregulated in CS neurons. The autophagy pathway in CS neurons may be associated with the pathophysiology exhibited in the neural network of CS patients.

Background: Congenital Zika syndrome causes a spectrum of neurological symptoms with varying effects on function that require different therapeutic strategies. To date, this spectrum of effects and its clinical implications have not been completely described. We describe the neurological examination findings in toddlers and preschoolers, including predominant symptom complexes and comorbidities., Methods: This study is a case-series neurological evaluation of 75 children with congenital Zika syndrome in Campina Grande, Brazil. The study is part of a cohort of children with congenital Zika syndrome that started in 2015 and is still ongoing. Children with Zika virus infection detected during pregnancy (mothers exhibited rash and were followed and diagnosed by fetal ultrasound abnormalities or RT-PCR) or through microcephaly screening after birth, using Intergrowth 21 guidelines, were selected by laboratory and radiological criteria. Children were examined during a 10-day period in September, 2018, and underwent neurological interview, examination, and assessment of functional outcomes and comorbidities. Children were divided in groups of predominant corticospinal or neuromuscular clinical signs and the associations between these groups and clinical comorbidities were assessed., Findings: All of the children recruited to the study from Nov 29, 2015 to Nov 30, 2017 had imaging correlates of congenital Zika syndrome. Children were assigned to groups depending on the signs exhibited, either corticospinal or neuromuscular, with or without dyskinetic signs. 75 children completed the evaluation, 38 (51%) girls and 37 (49%) boys. Median age was 33 months (range 26-40 months; IQR 29-34). Microcephaly was present at birth in 56 (75%) children, and 19 (25%) children were born with normal head circumference, 15 of whom later developed microcephaly. Neurological examination grouped four children as having isolated dyskinetic signs, 48 children were assigned to the corticospinal group and 23 into the neuromuscular group. Dyskinetic findings were present in 30 (40%) children, either alone (four [5%]) or combined with corticospinal (19 [40%] of 48) or neuromuscular (seven [30%] of 23) findings. Comorbidities were highly prevalent, and the neuromuscular group had worse functional outcomes, evaluated by gross motor function (p=0·026), manual abilities (p=0·0013), and communication function (p<0·0005) classification scales, than the corticospinal group, whereas pneumonia (p<0·0005) and urinary tract infections (p<0·0005) were more frequent in the corticospinal group. Cortical hyperexcitability was supported by several clinical correlates, such as early onset epilepsy, persistence of primitive reflexes, and dystonia., Interpretation: We describe distinct neurological profiles in the congenital Zika syndrome spectrum, with functional outcomes tending to correlate with these groups. The clinical division of children based on the disease signs proposed here is supported by the literature on central and peripheral nervous system pathology in congenital Zika syndrome. The high prevalence of dyskinetic symptoms merits special attention., Funding: Brazilian National Council for Scientific and Technological Development and by the Coordination for the Improvement of Higher Education Personnel., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Both point mutations and deletions of the MYT1L gene as well as microdeletions of chromosome band 2p25.3 including MYT1L are associated with intellectual disability, obesity, and behavioral problems. Thus, MYT1L is assumed to be the-at least mainly-causative gene in the 2p25.3 deletion syndrome. Here, we present comprehensive descriptions of nine novel individuals bearing MYT1L mutations; most of them single nucleotide variants (SNVs). This increases the number of known individuals with causative deletions or SNVs of MYT1L to 51. Since eight of the nine novel patients bear mutations affecting MYT1L only, the total number of such individuals now nearly equals the number of individuals with larger microdeletions affecting additional genes, allowing for a comprehensive phenotypic comparison of these two patient groups. For example, 55% of the individuals with mutations affecting MYT1L only were overweight or obese as compared to 86% of the individuals with larger microdeletions. A similar trend was observed regarding short stature with 5 versus 35%, respectively. However, these differences were nominally significant only after correction for multiple testing, further supporting the hypothesis that MYT1L haploinsufficiency is central to the 2p25.3 deletion phenotype. Most importantly, the large number of individuals with MYT1L mutations presented and reviewed here allowed for the delineation of a more comprehensive clinical picture. Seizures, postnatal short stature, macrocephaly, and microcephaly could be shown to be over-represented among individuals with MYT1L mutations., (© 2020 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals, Inc.)

Objective: Defects in ion channels and neurotransmitter receptors are implicated in developmental and epileptic encephalopathy (DEE). Metabotropic glutamate receptor 7 (mGluR7), encoded by GRM7, is a presynaptic G-protein-coupled glutamate receptor critical for synaptic transmission. We previously proposed GRM7 as a candidate disease gene in two families with neurodevelopmental disorders (NDDs). One additional family has been published since. Here, we describe three additional families with GRM7 biallelic variants and deeply characterize the associated clinical neurological and electrophysiological phenotype and molecular data in 11 affected individuals from six unrelated families., Methods: Exome sequencing and family-based rare variant analyses on a cohort of 220 consanguineous families with NDDs revealed three families with GRM7 biallelic variants; three additional families were identified through literature search and collaboration with a clinical molecular laboratory., Results: We compared the observed clinical features and variants of 11 affected individuals from the six unrelated families. Identified novel deleterious variants included two homozygous missense variants (c.2671G>A:p.Glu891Lys and c.1973G>A:p.Arg685Gln) and one homozygous stop-gain variant (c.1975C>T:p.Arg659Ter). Developmental delay, neonatal- or infantile-onset epilepsy, and microcephaly were universal. Three individuals had hypothalamic-pituitary-axis dysfunction without pituitary structural abnormality. Neuroimaging showed cerebral atrophy and hypomyelination in a majority of cases. Two siblings demonstrated progressive loss of myelination by 2 years in both and an acquired microcephaly pattern in one. Five individuals died in early or late childhood., Conclusion: Detailed clinical characterization of 11 individuals from six unrelated families demonstrates that rare biallelic GRM7 pathogenic variants can cause DEEs, microcephaly, hypomyelination, and cerebral atrophy., (© 2020 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association.)

Purpose: The aim of this study is to report on the phenotype and genotype of five patients diagnosed with Cohen syndrome, an extremely rare autosomal recessive disorder manifesting with mental and physiological defects., Methods: Five patients from three German families and one Syrian family underwent a comprehensive ophthalmological examination. The scheduled visual acuity measurements, fundus ophthalmoscopy, spectral domain optical coherence tomography (OCT), full-field electrophysiological recordings of scotopic and photopic electroretinograms (ERGs) and colour vision testing could not be carried out in all subjects, because of the mental and physical retardation. The genetic diagnosis was achieved by next-generation sequencing., Results: The ophthalmic and systemic phenotype of the patients is typical for Cohen syndrome including myopia, night blindness, photophobia, fundus pigmentary changes and bull's eye maculopathy. Electroretinograms (ERGs) were extinguished in the four patients, whose recording was possible. Genetic testing revealed homozygous or two heterozygous bi-allelic mutations in the VPS13B (COH1) gene in all five patients, with five different allelic variants observed. The homozygous mutation c.6055&#95;6056delGA; p.Asp2019Glnfs*15 in two sibling patients as well as the homozygous nonsense mutation c.8112C>G;p.Tyr2704* have not previously been reported., Conclusions: The phenotype of the five patients reported here is typical for Cohen syndrome; however, their genotype is heterogeneous. Two new allelic variants were found to be the causative mutation., (© 2019 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

A distinctive feature of neocortical development is the highly coordinated production of different progenitor cell subtypes, which are critical for ensuring adequate neurogenic outcome and the development of normal neocortical size. To further understand the mechanisms that underlie neocortical growth, we focused our studies on the microcephaly gene Mcph1, and we report here that Mcph1 (1) exerts its functions in rapidly dividing apical radial glial cells (aRGCs) during mouse neocortical development stages that precede indirect neurogenesis; (2) is expressed at mitochondria; and (3) controls the proper proliferation and survival of RGCs, potentially through crosstalk with cellular metabolic pathways involving the stimulation of mitochondrial activity via VDAC1/GRP75 and AKT/HK2/VDAC1 and glutaminolysis via ATF4/PCK2. We currently report the description of a MCPH-gene implication in the interplay between bioenergetic pathways and neocortical growth, thus pointing to alterations of cellular metabolic pathways, in particular glutaminolysis, as a possible cause of microcephalic pathogenesis., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Institut National de la Sante et de la Recherche Médicale. Published by Elsevier Inc. All rights reserved.)

Objective: To estimate the incidence of epilepsy in children with Zika-related microcephaly in the first 24 months of life; to characterize the associated clinical and electrographic findings; and to summarize the treatment responses., Methods: We followed a cohort of children, born during the 2015-2016 Zika virus (ZIKV) epidemic in Brazil, with congenital microcephaly and evidence of congenital ZIKV infection on neuroimaging and/or laboratory testing. Neurological assessments were performed at ≤3, 6, 12, 15, 18, 21, and 24 months of life. Serial electroencephalograms were performed over the first 24 months., Results: We evaluated 91 children, of whom 48 were female. In this study sample, the cumulative incidence of epilepsy was 71.4% in the first 24 months, and the main type of seizure was infantile spasms (83.1%). The highest incidence of seizures occurred between 3 and 9 months of age, and the risk remained high until 15 months of age. The incidence of infantile spasms peaked between 4 and 7 months and was followed by an increased incidence of focal epilepsy cases after 12 months of age. Neuroimaging results were available for all children, and 100% were abnormal. Cortical abnormalities were identified in 78.4% of the 74 children evaluated by computed tomography and 100% of the 53 children evaluated by magnetic resonance imaging. Overall, only 46.1% of the 65 children with epilepsy responded to treatment. The most commonly used medication was sodium valproate with or without benzodiazepines, levetiracetam, phenobarbital, and vigabatrin., Significance: Zika-related microcephaly was associated with high risk of early epilepsy. Seizures typically began after the third month of life, usually as infantile spasms, with atypical electroencephalographic abnormalities. The seizure control rate was low. The onset of seizures in the second year was less frequent and, when it occurred, presented as focal epilepsy., (© 2020 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy.)

Background: The type 1 insulin-like growth factor receptor (IGF1R) is a keystone of fetal growth regulation by mediating the effects of IGF-I and IGF-II. Recently, a cohort of patients carrying an IGF1R defect was described, from which a clinical score was established for diagnosis. We assessed this score in a large cohort of patients with identified IGF1R defects, as no external validation was available. Furthermore, we aimed to develop a functional test to allow the classification of variants of unknown significance (VUS) in vitro., Methods: DNA was tested for either deletions or single nucleotide variant (SNV) and the phosphorylation of downstream pathways studied after stimulation with IGF-I by western blot analysis of fibroblast of nine patients., Results: We detected 21 IGF1R defects in 35 patients, including 8 deletions and 10 heterozygous, 1 homozygous and 1 compound-heterozygous SNVs. The main clinical characteristics of these patients were being born small for gestational age (90.9%), short stature (88.2%) and microcephaly (74.1%). Feeding difficulties and varying degrees of developmental delay were highly prevalent (54.5%). There were no differences in phenotypes between patients with deletions and SNVs of IGF1R . Functional studies showed that the SNVs tested were associated with decreased AKT phosphorylation., Conclusion: We report eight new pathogenic variants of IGF1R and an original case with a homozygous SNV. We found the recently proposed clinical score to be accurate for the diagnosis of IGF1R defects with a sensitivity of 95.2%. We developed an efficient functional test to assess the pathogenicity of SNVs, which is useful, especially for VUS., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To present the clinical picture, the associated complications and the genetic findings of Jordanian patients diagnosed with Congenital insensitivity to pain with anhidrosis (CIPA)., Patients and Methods: This is a retrospective study including 7 patients diagnosed with CIPA presenting to Jordan University Hospital neurology clinic between 2001 and 2017., Results: Among five families, seven patients were diagnose with CIPA and followed for a period ranging from one month to 6 years. The initial symptom observed in all patients was high fever in the first few days after birth, decreased sensation to pain and decreased sweating were later noted. Poor weight gain, microcephaly and global developmental delay were present in most cases. All patients had tongue ulcerations. Fingers/toes ulcerations were present in 6/7 (86.0 %), hip joint dislocation in 3/7 (43.0 %), chronic arthritis and joint swelling in 6/7 (86.0 %), corneal ulcers in 4/7 (57.1 %) and kidney amyloidosis in 1/7 (13.0 %) of all patients. Death occurred in 4/7 (57.1 %) patients. Consanguinity was present in all families. Mutation analysis revealed three variants in NTRK1 gene. The frameshift (c.1860&#95;1861insT; p.Pro621fs) mutation was common in our series. One patient carried a novel missense mutation (c.2170 G > A; p.Gly724Ser). The third missense mutation (C2125 G > T; p.Val709Leu) was reported in a previous study in one patient., Conclusion: This cohort reveals a severe CIPA phenotype necessitating thorough multidisciplinary care and follow up., Competing Interests: Declaration of Competing Interest All authors declare no conflict of interest., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Mowat-Wilson syndrome is a genetic disorder associated with a variable phenotype including peculiar facial features associated with intellectual disability, epilepsy, language impairment, and multiple congenital anomalies caused by heterozygous mutation of the ZEB2 gene. The ZEB2 protein is a complex transcription factor that encompasses multiple functional domains that interact with the regulatory regions of target genes including those involved in brain development. Recently, it has been documented that ZEB2 regulates the differentiation of interneuron progenitors migrating from the medial ganglionic eminence to cortical layers by repression of the Nkx2-1 homeobox transcription factor. It has therefore been suggested that the deficit in ZEB2 may induce an imbalance of neuronal inhibition/excitation leading to epileptic seizures. Given the phenotypic variability of Mowat-Wilson syndrome, to date, a distinctive genotype-phenotype correlation has not been delineated. Here, we report a patient with a severe phenotype of Mowat-Wilson syndrome, associated with a novel heterozygous de novo frame-shift variant in the ZEB2 gene, as well as an additional novel heterozygous missense variant in the SCN1A gene, the mutation of which is known to affect NaV1.1-mediated sodium current in GABAergic interneurons. We hypothesize that the severe neurological phenotype of our patient may be influenced by the coexistence of both genetic mutations. [Published with video sequence].

Objective: To assess the gross motor development of children with presumed congenital Zika virus (ZIKV) infection over the first 2 years of their lives., Methods: Seventy-seven children were assessed at the median ages of 11, 18, and 24 months, using the evaluative instrument Gross Motor Function Measure (GMFM-66). At the third assessment, the children with diagnoses of cerebral palsy (CP) were classified by severity through the Gross Motor Function Classification System (GMFCS) and stratified by topography indicating the predominantly affected limbs. With these instruments in combination and using the motor development curves as reference, the rate of development and functional ability were estimated., Results: At 2 years of age, all children had the diagnosis of CP. Seventy-four (96.1%) presented gross motor skills similar to those of children aged 4 months or younger, according to the World Health Organization's standard. The GMFM-66 median score among the 73 (94.8%) children with quadriplegia and GMFCS level V showed significant change between 11 and 18 months (p < 0.001) and between 11 and 24 months (p < 0.001). No significant difference (p = 0.076) was found between 18 and 24 months., Conclusion: Despite showing some gross motor progress during the initial 18 months of life, these children with presumed congenital ZIKV infection and CP experienced severe motor impairment by 2 years of age. According to the motor development curves, these children with quadriplegia have probably already reached about 90% of their motor development potential.

Biallelic mutations in the cyclin-dependent kinase 5 regulatory subunit-associated protein 2 gene CDK5RAP2 cause autosomal recessive primary microcephaly type 3 (MCPH3). MCPH is characterized by intellectual disability and microcephaly at birth, classically without further organ involvement. Only recently, congenital cataracts were reported in four patients of one pedigree with MCPH3. Given the lack of a further pedigree with this phenotype, it remained unclear whether this was a true causal relationship. Here we support the link between CDK5RAP2 and eye development by showing that most Cdk5rap2 mutant mice (an/an) exhibit eye malformations ranging from reduced size of one or both eyes (microphthalmia) to total absence of both eyes (anophthalmia). We also detected increased apoptosis in the an/an retinal progenitor cells associated with more mitotic cells. This indicates an important role of Cdk5rap2 in physiologic eye development., (© 2019 The Authors. Annals of Human Genetics published by University College London (UCL) and John Wiley & Sons Ltd.)

The conserved transport protein particle (TRAPP) complexes regulate key trafficking events and are required for autophagy. TRAPPC4, like its yeast Trs23 orthologue, is a core component of the TRAPP complexes and one of the essential subunits for guanine nucleotide exchange factor activity for Rab1 GTPase. Pathogenic variants in specific TRAPP subunits are associated with neurological disorders. We undertook exome sequencing in three unrelated families of Caucasian, Turkish and French-Canadian ethnicities with seven affected children that showed features of early-onset seizures, developmental delay, microcephaly, sensorineural deafness, spastic quadriparesis and progressive cortical and cerebellar atrophy in an effort to determine the genetic aetiology underlying neurodevelopmental disorders. All seven affected subjects shared the same identical rare, homozygous, potentially pathogenic variant in a non-canonical, well-conserved splice site within TRAPPC4 (hg19:chr11:g.118890966A>G; TRAPPC4: NM&#95;016146.5; c.454+3A>G). Single nucleotide polymorphism array analysis revealed there was no haplotype shared between the tested Turkish and Caucasian families suggestive of a variant hotspot region rather than a founder effect. In silico analysis predicted the variant to cause aberrant splicing. Consistent with this, experimental evidence showed both a reduction in full-length transcript levels and an increase in levels of a shorter transcript missing exon 3, suggestive of an incompletely penetrant splice defect. TRAPPC4 protein levels were significantly reduced whilst levels of other TRAPP complex subunits remained unaffected. Native polyacrylamide gel electrophoresis and size exclusion chromatography demonstrated a defect in TRAPP complex assembly and/or stability. Intracellular trafficking through the Golgi using the marker protein VSVG-GFP-ts045 demonstrated significantly delayed entry into and exit from the Golgi in fibroblasts derived from one of the affected subjects. Lentiviral expression of wild-type TRAPPC4 in these fibroblasts restored trafficking, suggesting that the trafficking defect was due to reduced TRAPPC4 levels. Consistent with the recent association of the TRAPP complex with autophagy, we found that the fibroblasts had a basal autophagy defect and a delay in autophagic flux, possibly due to unsealed autophagosomes. These results were validated using a yeast trs23 temperature sensitive variant that exhibits constitutive and stress-induced autophagic defects at permissive temperature and a secretory defect at restrictive temperature. In summary we provide strong evidence for pathogenicity of this variant in a member of the core TRAPP subunit, TRAPPC4 that associates with vesicular trafficking and autophagy defects. This is the first report of a TRAPPC4 variant, and our findings add to the growing number of TRAPP-associated neurological disorders., (© The Author(s) (2019). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The implications of Zika Virus exposure in pregnancy for early infant growth remains poorly described. The main goal of this study is to compare the growth, body composition, and feeding modality of infants in the first three months of life by prenatal Zika Virus exposure status. We selected an analytical cohort of 115 infants born without microcephaly, comprising 56 infants with qRT-PCR confirmed exposure to ZIKV during gestation and 59 infants born to women with presumptively no evidence of ZIKV in pregnancy. Infants were evaluated at birth, 1 and 3 months of age in terms of anthropometrics, body composition All the results were adjusted by maternal age, maternal BMI and gestational age. We observe no differences between anthropometric measurements at birth. Mothers in exposed group showed higher BMI. At 1 month and 3 months of age there were differences in mid arm circumference, arm muscle circumference and fat free mass. Weight and length was less in the ZIKV exposed in pregnancy infants and statistically different at 3 month of age. The findings of this investigation provide new evidence that ZIKV exposure in pregnancy may be associated with differences in body composition.

The primary cilium is a signaling center critical for proper embryonic development. Previous studies have demonstrated that mice lacking Ttc21b have impaired retrograde trafficking within the cilium and multiple organogenesis phenotypes, including microcephaly. Interestingly, the severity of the microcephaly in Ttc21baln/aln homozygous null mutants is considerably affected by the genetic background and mutants on an FVB/NJ (FVB) background develop a forebrain significantly smaller than mutants on a C57BL/6J (B6) background. We performed a Quantitative Trait Locus (QTL) analysis to identify potential genetic modifiers and identified two regions linked to differential forebrain size: modifier of alien QTL1 (Moaq1) on chromosome 4 at 27.8 Mb and Moaq2 on chromosome 6 at 93.6 Mb. These QTLs were validated by constructing congenic strains. Further analysis of Moaq1 identified an orphan G-protein coupled receptor (GPCR), Gpr63, as a candidate gene. We identified a SNP that is polymorphic between the FVB and B6 strains in Gpr63 and creates a missense mutation predicted to be deleterious in the FVB protein. We used CRISPR-Cas9 genome editing to create two lines of FVB congenic mice: one with the B6 sequence of Gpr63 and the other with a deletion allele leading to a truncation of the GPR63 C-terminal tail. We then demonstrated that Gpr63 can localize to the cilium in vitro. These alleles affect ciliary localization of GPR63 in vitro and genetically interact with Ttc21baln/aln as Gpr63;Ttc21b double mutants show unique phenotypes including spina bifida aperta and earlier embryonic lethality. This validated Gpr63 as a modifier of multiple Ttc21b neural phenotypes and strongly supports Gpr63 as a causal gene (i.e., a quantitative trait gene, QTG) within the Moaq1 QTL., Competing Interests: The authors have declared that no competing interests exist.

Thiamine metabolism dysfunction syndrome-4 (THMD4) includes episodic encephalopathy, often associated with a febrile illness, causing transient neurologic dysfunction and a slowly progressive axonal polyneuropathy. Until now only two mutations (G125S and S194P) have been reported in the SLC25A19 gene as causative for this disease and a third mutation (G177A) as related to the Amish lethal microcephaly. In this work, we describe the clinical and molecular features of a patient carrying a novel mutation (c.576G>C; Q192H) on SLC25A19 gene. Functional studies on this mutation were performed explaining the pathogenetic role of c.576G>C in affecting the translational efficiency and/or stability of hMTPPT protein instead of the mRNA expression. These findings support the pathogenetic role of Q192H (c.576G>C) mutation on SLC25A19 gene. Moreover, despite in other patients the thiamine supplementation leaded to a substantial improvement of peripheral neuropathy, our patient did not show a clinical improvement.

The present study describes two patients with clinical diagnosis of ID, from a consanguineous family in Israel. Whole exome sequencing identified a homozygous missense mutation in the ADAT3 gene. The clinical features of our patients were compared with several cases described in two recently published studies that documented clinical manifestation of this same mutation. Both affected siblings in our study expressed the previously described clinical features such as intellectual disability, strabismus, FTT/underweight, microcephaly and hypotonia. Interestingly, our patients suffered from additional clinical manifestations that were not detailed in the previous two studies, such as: gait difficulties, instability, teeth abnormalities, neuropathy and contractures of the hand wrist and fingers. We conclude that the ADAT3 gene mutation is responsible for ADAT3-related ID syndrome, which induces the variety clinical manifestations exhibited by our patients. Further studies aimed at identifying and characterizing additional afflicted families worldwide will be required to obtain a more comprehensive understanding of this syndrome., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Objective: To describe the nutritional profile of newborns with microcephaly and factors associated with worse outcomes during the first 14 days of life., Methods: This investigation is a longitudinal, descriptive study carried out in 21 full-term neonates exposed vertically to the Zika virus and hospitalized in a neonatal intensive care unit from February to September 2016. Patients receiving parenteral nutrition were excluded. Data analysis was performed using a generalized estimating equation model and Student's t-test to evaluate the association between worsening weight-for-age z-scores and independent clinical, sociodemographic and nutritional variables during hospitalization, with p<0.05 indicating significance., Results: During hospitalization, there was a decrease in the mean values of the weight-for-age z-scores. The factors associated with worse nutritional outcomes were symptomatic exposure to the Zika virus, low maternal schooling, absence of maternal income and consumption of infant formula (p<0.05). Calcification and severe microcephaly were also associated with poor nutritional outcomes. Energy and macronutrient consumption remained below the recommendations and had an upward trend during hospitalization., Conclusion: The presence of cerebral calcification, the severity of microcephaly and symptomatic maternal exposure to Zika virus affected the nutritional status of newborns. In terms of nutritional factors, human milk intake had a positive impact, reducing weight loss in the first days of life. Other known factors, such as income and maternal schooling, were still associated with a poor nutritional status.

Asparagine synthetase deficiency is a rare autosomal recessive neurometabolic disorder caused by mutations in the asparagine synthetase gene. It is characterized by congenital microcephaly, intellectual disability, progressive cerebral atrophy, and intractable seizures. A decrease in asparagine in CSF or plasma guides subsequent investigations in some cases, but normal values are described in other cases. Therefore, reaching a diagnosis is challenging and relies on exome sequencing. We report the case of a child with progressive microcephaly, irritability, startle reflexes, and jitteriness since birth. Focal clonic and myoclonic seizures, status epilepticus, and infantile spasms appeared in the first months of life. At first, the EEG showed multifocal epileptic activity which later turned into modified hypsarrhythmia and discontinuous activity. Brain MRI showed brain atrophy, a simplified gyral pattern, and poor myelination. Plasma asparagine levels were normal. Due to remote parental consanguinity, a study of contiguous regions of runs of homozygosity was performed, showing a 5-Mb region (chr7:95629078-100679007) including the asparagine synthetase gene. The molecular analysis of this gene led to identification of a novel homozygous missense mutation, c.761G>T(p.Gly254Val), in our patient. The peculiar electroclinical phenotype may lead to diagnostic suspicion and molecular analysis which may benefit genetic counselling. [Published with video sequence].

Development of the human brain is a strictly complex and precisely regulated process. Brain development includes the proliferation and differentiation of neural progenitor cells, migration and maturation of neurons, myelination of neuronal axons, synaptogenesis and organization of the neural circuits. Abnormalities of these developmental processes can lead to severe malformation and dysfunction of the brain, which may result in brain developmental diseases which have a high medical burden and have attracted global attention. Brain developmental diseases are typically divided into two categories according to abnormal brain morphology and dysfunction: malformation of cortical development (MCD) and neuropsychopathy. Microcephaly and autism spectrum disorder (ASD) are representative disorders of MCD and neuropsychopathy respectively. In this review, we summarize the progresses of these two typical and relevant brain developmental diseases including the mechanism and etiology of their development, gene expression, symptoms, and related to provide theoretical guidance for basic research and management and treatment.

De novo pathogenic variants in the human immunodeficiency virus enhancer type I binding protein 2 (HIVEP2) gene, a large transcription factor predominantly expressed in the brain have previously been associated with intellectual disability (ID) and dysmorphic features in nine patients. We describe the phenotype and genotype of two additional patients with novel de novo pathogenic HIVEP2 variants, who have previously unreported features, including hyperphagia and Angelman-like features. Exome sequencing was utilized in the investigation of the patients who had previously incurred a rigorous genetic workup for their neurodevelopmental delay, and in whom no genetic cause had been detected. Information pertaining to phenotype and genotype for new patients was collated along with data from previous reports, showing that the phenotypic spectrum of patients with HIVEP2 variants is broader than first noted. Additional characteristics are: an increased body mass index; and features of Angelman-like syndromes including: ID, limited speech, post-natal microcephaly, and hypotonia. Dysmorphic features vary between patients. As yet, no clear association between the type of gene aberration and phenotype can be concluded. HIVEP2-related ID needs to be considered in the differential diagnosis of patients with Angelman-like phenotypes and hyperphagia, and whole-exome sequencing should be considered in the genetic diagnostic armamentarium for patients with ID of inconclusive etiology., (© 2019 Wiley Periodicals, Inc.)

Raine syndrome is a rare, autosomal recessive, osteosclerotic bone dysplasia due to pathogenic variants in FAM20C. The clinical phenotype is characterized by generalized osteosclerosis affecting all bones, cerebral calcifications, and craniofacial dysmorphism. Most cases present during the neonatal period with early lethality due to pulmonary hypoplasia and respiratory compromise while only few affected individuals have been reported to survive into adulthood. FAM20C is a ubiquitously expressed protein kinase that contains five functional domains including a catalytic domain, a binding pocket for FAM20A and three distinct N-glycosylation sites. We report a newborn infant with a history of prenatal onset fractures, generalized osteosclerosis, and craniofacial dysmorphism and early lethality. The clinical presentation was highly suggestive of Raine syndrome. A homozygous, novel missense variant in exon 5 of FAM20C (c.1007T>G; p.Met336Arg) was identified by targeted Sanger sequencing. Following in silico analysis and mapping of the variant on a three-dimensional (3D) model of FAM20C it is predicted to be deleterious and to affect N-glycosylation, protein folding, and subsequent secretion of FAM20C. In addition, we reviewed all published FAM20C mutations and observed that most pathogenic variants affect functional regions within the protein establishing evidence for an emerging genotype-phenotype correlation., (© 2019 Wiley Periodicals, Inc.)

Congenital microcephaly is highly associated with intellectual disability. Features of autosomal recessive primary microcephaly subtype 3 (MCPH3) also include hyperactivity and seizures. The disease is caused by biallelic mutations in the Cyclin-dependent kinase 5 regulatory subunit-associated protein 2 gene CDK5RAP2. In the mouse, Cdk5rap2 mutations similar to the human condition result in reduced brain size and a strikingly thin neocortex already at early stages of neurogenesis that persists through adulthood. The microcephaly phenotype in MCPH arises from a neural stem cell proliferation defect. Here, we report a novel role for Cdk5rap2 in the regulation of dendritic development and synaptogenesis of neocortical layer 2/3 pyramidal neurons. Cdk5rap2-deficient murine neurons show poorly branched dendritic arbors and an increased density of immature thin spines and glutamatergic synapses in vivo. Moreover, the excitatory drive is enhanced in ex vivo brain slice preparations of Cdk5rap2 mutant mice. Concurrently, we show that pyramidal neurons receive fewer inhibitory inputs. Together, these findings point towards a shift in the excitation - inhibition balance towards excitation in Cdk5rap2 mutant mice. Thus, MCPH3 is associated not only with a neural progenitor proliferation defect but also with altered function of postmitotic neurons and hence with altered connectivity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Recent developments in 3D cultures exploiting the self-organization ability of pluripotent stem cells have enabled the generation of powerful in vitro systems termed brain organoids. These 3D tissues recapitulate many aspects of human brain development and disorders occurring in vivo. When combined with improved differentiation methods, these in vitro systems allow the generation of more complex "assembloids," which are able to reveal cell diversities, microcircuits, and cell-cell interactions within their 3D organization. Here, the ways in which human brain organoids have contributed to demystifying the complexities of brain development and modeling of developmental disorders is reviewed and discussed. Furthermore, challenging questions that are yet to be addressed by emerging brain organoid research are discussed., (© 2019 The Authors. BioEssays Published by Wiley Periodicals, Inc.)