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Background: The COVID-19 pandemic outbreak has dramatically disrupted healthcare systems. Two rapid WHO pulse surveys studied disruptions in mental health services, but did not particularly focus on neurology. Here, a global survey was conducted and addresses the impact of the pandemic on neurology services. Methods: A cross-sectional study was carried out in which 34 international neurological associations were asked to distribute the survey to national associations. The responses represented the national situation, in November–December 2020, with regard to the main disrupted neurological services, reasons and the mitigation strategies implemented as well as the disruption on training of residents and on neurological research. A comparison with the situation in February–April 2020, first pandemic wave, was also requested. Findings: 54 completed surveys came from 43 countries covering all the 6 WHO regions. Overall, neurological services disruption was reported as mild by 26%, moderate by 30%, complete by 13% of associations. The most affected services were cross-sectoral neurological services (57%) and neurorehabilitation (56%). The second wave of the pandemic, however, was associated with the improvement of service provision for diagnostics services (44%) and for neurorehabilitation (41%). Governmental directives were the major cause of services' disruption (56%). Mitigation strategies were mostly established through telemedicine (48%). Almost half of respondents reported a significant impact on neurological research (48%) and educational activities (60%). Most associations (67%) were not involved in decision making for neurological patients' issues by their national government. Interpretation: The COVID-19 pandemic affects neurological services and raises the universal need for the development of neurological health care at the policy, systems and services levels. A global national plan on mitigation strategies for disruption of neurological services during pandemic situations should be established and neurological scientific and patients associations should get involved in decision making. [ABSTRACT FROM AUTHOR]

• The co-existence of the two mutations in two candidate genes. • Severity score was evaluated by "Rett Assessment Rating Scale" (R.A.R.S.). • Analysis of gene expression of CDKL5, MeCP2, Dnmt1 and MYCN mutants. Rett syndrome (RTT) is a neuro-developmental disorder affecting almost exclusively females and it divided into classical and atypical forms of the disease. RTT-like syndrome was also described and presents an overlapping phenotype of RTT. RTT-like syndrome has been associated with several genes including MECP2 and CDKL5 having common biological pathways and regulatory interactions especially during neural maturation and synaptogenesis. We report patient with Rett-like syndrome for whom clinical features and their progression guided toward the screening of two candidate genes MECP2 and CDKL 5 by sequencing. Severity score was evaluated by "Rett Assessment Rating Scale" (R.A.R.S.). Predictions of pahogenicity and functional effects used several bioinformatic tools and qRT-PCR was conducted to evaluate gene expression. Mutational screening revealed two mutations c.1065 C > A (p.S355R) in MECP2 gene and c.616 G > A (p.D206N) mutation in CDKL5 gene in the patient with a high R.A.R.S. Bioinformatic investigations predicted a moderate effect of p.S355R in MECP2 gene but a more pathogenic one of p.D206N mutation in CDKL5. Effect of c.616 G > A mutation on structure and stability of CDKL5 mRNA was confirmed by qRT-PCR. Additionally, analysis of gene expression revealed a drastic effect of CDKL5 mutant on its MeCP2 and Dnmt1 substrates and also on its MYCN regulator. The co-existence of the two mutations in CDKL5 and MECP2 genes could explain the severe phenotype in our patient with RTT-Like and is consistent with the data related to the interactions of CDKL5 with MeCP2 and Dnmt1 proteins. [ABSTRACT FROM AUTHOR]

• Mutational analysis of MECP2 gene and a whole mitochondrial genome screening was performed in a Tunisian patient with Angelman-like syndrome. • Identification of an unusual novel double mutation (c.397C > T in trans with c.608C > T) in MECP2 gene. • First direct molecular evidence of father-to-girl transmission of the c.608C > T mutation at mosaic state in Angelman-like syndrome. • Identification of the mitochondrial m.827A > G mutation in the MT-RNR1 for the first time in AS-like syndrome. Mutations in Methyl-CpG-Binding protein 2 (MECP2), located on Xq28 and encoding a methyl CpG binding protein, are commonly related to Rett syndrome. However, MECP2 mutations have already been reported in patients with neurodevelopmental abnormalities such as X-linked mental retardation, severe neonatal encephalopathy and Angelman-like syndrome (AS-like). Accordingly, we report the clinical, molecular and bioinformatic analyses in a Tunisian patient with AS-like phenotype. In fact, the direct sequencing of MECP2 and cloning essay reveals the emergence of an unusual novel double mutation, including a de novo mutation c.397C > T (p.R133C) and an inherited one c.608C > T (p.T203 M) co-occurring in Trans. We also provide the molecular evidence of the c.608C > T transmission to the patient which was present in her father at somatic mosaicism state. To gain insight into the molecular basis of this disorder, we undertook, for the first time, a whole mitochondrial genome mutational analysis. Thus, the results showed the presence of several variations and a homoplasmic mutation m.827A > G in the MT-RNR1 gene, leading to the disruption of the 12S rRNA secondary structure. Our report is considered as the first to describe an unusual novel double mutation (c.397C > T in trans with c.608C > T) in MECP2 co-occurring with the mitochondrial m.827A > G mutation in the MT-RNR1 gene in a Tunisian patient with AS-like. Besides, our results highlight the importance of studying MECP2 and the significance of mDNA screening in AS-like disorder for a better understanding of its etiopathogenesis. [ABSTRACT FROM AUTHOR]

Highlights • The novel c.2788insG mutation causes impairment of alternative splicing of exon 19 and the lack of a part of the proteasome signal which could disrupt the dynamic regulation of isoform levels especially hCDKL5_5 and hCDKL5_1. • Novel truncated mutation p.E930Gfs9X in the C-terminal domain and causing the lack of the signal peptidase I serine active site. • Comparison of subcellular mutated protein localization from truncated mutations among the C-terminal domain suggested that the signal peptidase I serine active site might be responsible for the nucleus to cytoplasm cross of hCDKL5_5 protein. • Comparison of associated patient phenotypes resulting from truncated mutations among the C-terminal domain wherever the localization of the truncated mutations among the C-terminal domain is, the resulting phenotypes are almost similar and are always severe. Abstract Introduction West Syndrome is a severe epileptic encephalopathy characterized by epileptic spasms, hypsarrhythmia, and regression of psychomotor acquisitions beginning in the first year of life. ARX and CDKL5 genes were identified as linked to the most frequent genetic causes of West Syndrome. Methods The present study reports the clinical, molecular and bioinformatic investigation of the patient with severe West syndrome. Results Molecular analysis of the two candidate genes, i.e. ARX and CDKL5 showed the presence of a novel insertion c.2788insG in exon 19 of CDKL5 gene. This mutation causes changes in cis regulation elements of exon 19 splicing and in secondary pre-mRNA structure leading probably to inclusion of alternative exon 19 in hCDKL5_5 isoform for which foetal brain expression was recently confirmed. This insertion led also to a frameshift mutation and generated a premature stop codon (p.E930Gfs9X) in the C- terminal domain and causing the lack of a part of the signal recognized by proteasome as well as the lack of peptidase I serine active site. Moreover, we review previously described, truncated mutations occurring in different regions of the C- terminal domain, and we compared the subcellular mutated protein localization and their resulting patients' phenotypes. Conclusions The impairment of alternative splicing of exon 19 and the lack of a part of the proteasome signal due to c.2788insG mutation could disrupt the dynamic regulation of isoform levels especially hCDKL5_5 and hCDKL5_1 during pre and postnatal neurodevelopment and then could cause pathogenic phenotype. Signal peptidase I serine active site seems to modulate hCDKL5_5 movements between nucleus and cytoplasm. We noticed that the resulting phenotypes from truncated mutations among the C-terminal domain of hCDKL5 are almost similar and are always severe. [ABSTRACT FROM AUTHOR]

• Lack of knowledge was noticed even among people with a family history of epilepsy. • The general attitude observed in our population was acceptable. • Familiarity with epilepsy did not significantly impact knowledge and attitudes. Epilepsy is one of the most stigmatizing disorders. Stigma and negative attitudes associated with epilepsy are due to poor public awareness and knowledge. This study evaluated knowledge, awareness, and attitude toward epilepsy among Tunisian general population. This was a cross-sectional study conducted between 2017 and 2019. On national epilepsy day on February and during awareness campaigns at Sfax Tunisia, we asked people who visited the epilepsy stand to anonymously answer a 31-item questionnaire on epilepsy. Five hundred and four participants have been included. About 43.6% of participants had personal or familial history of epilepsy. More than seventy percent of subjects thought that epilepsy is a neurological disease and 34.1% believed it is psychiatric. Majority (92.1%) of our population believed that epilepsy is non-contagious but 37.7% thought it is hereditary and 55.8% thought it causes intellectual deficiency. EEG was the most reported diagnostic method (61.7%). The two most popular therapeutic modalities reported in our population were drug treatment alone (85.3%) and associated with Quran (35.3%). Most (91.1%) of people thought that a person with epilepsy can get married. A person with epilepsy is able to study according to 92.7% of respondents, but 66.3% assumed that he/she suffers from difficulty concentrating. Subjects younger than 45 years were more aware of the ability of people with epilepsy to study and get married. We did not find any significant differences in knowledge and attitudes between subjects familiar with epilepsy and the rest of the population. The public knowledge and attitudes toward epilepsy were acceptable with regard to this study. However, negative attitudes and misunderstanding still exist. [ABSTRACT FROM AUTHOR]

We report three Tunisian patients affected by congenital muscular dystrophy with mental retardation and cerebellar cysts on cranial magnetic resonance imaging. The clinical features were characterized by hypotonia at birth, joint contractures associated with severe psychomotor retardation, absence of speech, inability to walk in three patients, but calf hypertrophy was noted only in two patients. Brain magnetic resonance imaging showed several cerebellar cysts and vermis hypoplasia in all of the patients. Abnormality of the white matter was present in two patients. The pattern of gyration was normal in all cases. Serum creatine kinase was elevated in all three cases and their muscle biopsy showed dystrophic changes compatible with congenital muscular dystrophy. The immunohistochemical analysis of the skeletal muscle revealed partial merosin deficiency, more pronounced for the N-terminal antibody. Linkage analysis excluded congenital muscular dystrophy loci on chromosomes 6q22, 9q31, 1p32 and 1q42. These patients constituted a particular form of congenital muscular dystrophy with a combination of severe motor delay, mental retardation, partial merosin deficiency and cerebellar cysts. Two patients showed white matter abnormalities on magnetic resonance imaging and hypertrophy of the calves. These cases, in addition to those reported previously, confirmed the large phenotypic variability in the group of secondary merosin deficiency congenital muscular dystrophy. [Copyright &y& Elsevier]

A variety of terms, such as "antiepileptic," "anticonvulsant," and "antiseizure" have been historically applied to medications for the treatment of seizure disorders. Terminology is important because using terms that do not accurately reflect the action of specific treatments may result in a misunderstanding of their effects and inappropriate use. The present International League Against Epilepsy (ILAE) position paper used a Delphi approach to develop recommendations on English‐language terminology applicable to pharmacological agents currently approved for treating seizure disorders. There was consensus that these medications should be collectively named "antiseizure medications". This term accurately reflects their primarily symptomatic effect against seizures and reduces the possibility of health care practitioners, patients, or caregivers having undue expectations or an incorrect understanding of the real action of these medications. The term "antiseizure" to describe these agents does not exclude the possibility of beneficial effects on the course of the disease and comorbidities that result from the downstream effects of seizures, whenever these beneficial effects can be explained solely by the suppression of seizure activity. It is acknowledged that other treatments, mostly under development, can exert direct favorable actions on the underlying disease or its progression, by having "antiepileptogenic" or "disease‐modifying" effects. A more‐refined terminology to describe precisely these actions needs to be developed. [ABSTRACT FROM AUTHOR]

Metachromatic leukodystrophy (MLD) is a severe metabolic disorder caused by the deficient activity of arylsulfatase A due to ARSA gene mutations. According to the age of onset, MLD is classified into three forms: infantile, juvenile, and adult. In our study, we aimed to perform a genetic analysis for two siblings with juvenile MLD for a better characterization of the molecular mechanisms behind the disease. A consanguineous family including two MLD patients (PII.1 and PII.2) was enrolled in our study. The diagnosis was made based on the clinical and neuroimaging investigations. The sequencing of ARSA gene was performed followed by in silico analysis. Besides, the cis/trans distribution of the variants was verified through a PCR‐RFLP. The ARSA gene sequencing revealed three known variants, two exonic c.1055A > G and c.1178C > G and an intronic one (c.1524 + 95A > G) in the 3′UTR region. All variants were present at heterozygous state in the two siblings and their mother. The assessment of the cis/trans distribution showed the presence of these variants in cis within the mother, while PII.2 and PII.2 present the c.1055A > G/c.1524 + 95A > G and the c.1178C > G in trans. Additionally, PII.1 harbored a de novo novel missense variant c.1119G > T, whose pathogenicity was supported by our predictive results. Our genetic findings, supported by a clinical examination, confirmed the affection of the mother by the adult MLD. Our results proved the implication of the variable distribution of the found variants in the age of MLD onset. Besides, we described a variable severity between the two siblings due to the de novo pathogenic variant. In conclusion, we identified a complex genotype of ARSA variants within two MLD siblings with a variable severity due to a de novo variant present in one of them. Our results allowed the establishment of an adult MLD diagnosis and highlighted the importance of an assessment of the trans/cis distribution in the cases of complex genotypes. [ABSTRACT FROM AUTHOR]

Moyamoya angiopathy is a rare cerebral vasculopathy and an underdiagnosed cause of arterial ischemic stroke in children. We aim to report the clinical and radiological presentations in a Tunisian pediatric cohort. We identified moyamoya angiopathy in pediatric patients managed at the Child Neurology Department of Hedi Chaker Sfax University Hospital between 2008 and 2020 and reviewed their clinical and radiological data as well as their evolutionary profile. We collected 14 patients with median age 40.6 months and a female predominance (sex ratio of 0.75). An arterial ischemic stroke (AIS) revealed the disease in all patients, with the major symptom being a motor deficit. Symptoms related to a transient ischemic attack before the diagnostic consultation were reported in four patients. Carotid territory was, clinically and radiologically, the most frequently involved. Brain magnetic resonance imaging with angiography was performed in 12 patients confirming the diagnosis by revealing the development of collateral vessels. All the investigations concluded to moyamoya disease in 57.2% and moyamoya syndrome in 42.8%. The latter was related to Down syndrome in five patients and neurofibromatosis type 1 in one patient. With a mean follow-up of 2.35 years, two patients had at least two more AISs during the first two years following diagnosis and 42.8% of patients were diagnosed with vascular or poststroke epilepsy. Full recovery was noted in 14.3% of cases. Moyamoya angiopathy in children is a serious condition that needs to be recognized due to the high risk of recurrent ischemic strokes. [ABSTRACT FROM AUTHOR]

Introduction: Epileptic encephalopathies (EEs) are a group of heterogeneous epileptic syndromes characterized by early‐onset refractory seizures, specific EEG abnormalities, developmental delay or regression and intellectual disability. The genetic spectrum of EE is very wide with mutations in a number of genes having various functions, such as those encoding AMPA ionotropic and glutamate receptors as well as voltage‐gated ion channels. However, the list of EE‐responsible genes could certainly be enlarged by next‐generation sequencing. Patients and methods: The present study reports a clinical investigation and a molecular analysis by the whole exome sequencing (WES) and pyrosequencing of a patient's family affected by epileptic spasms and severe psychomotor delay. Results: Clinical and radiological investigations revealed that the patient presented clinical features of severe and drug‐resistant EE‐type infantile epileptic spasm syndrome that evolved to Lennox Gastaut syndrome with radiological findings of hypomyelinated leukodystrophy. The results of WES revealed the presence of a novel heterozygous c.466C>T mutation in exon 4 of the TUBB4A gene in the patient. This transition led to the replacement of arginine by cysteine at position 156 (p.R156C) of the conserved helix 4 among the N‐terminal domain of the TUBB4A protein. Bioinformatic tools predicted its deleterious effects on the structural arrangement and stability of the protein. The presence of the mutation in the asymptomatic father suggested the hypothesis of somatic mosaicism that was tested by pyrosequencing of DNA from two tissues of the patient and her father. The obtained results showed a lower rate of mutated alleles in the asymptomatic father compared with the affected daughter in both lymphocytes and buccal mucosa cells, confirming the occurrence of paternal mosaicism. The phenotypic features of the patient were also compared with those of previously described patients presenting TUBB4A mutations. Conclusions: Our study is the first to report a disease‐causing variant in the TUBB4A gene in a patient with EE associated with hypomyelinated leucodystrophy. In addition, we expanded the phenotypic spectrum associated with the TUBB4A gene. [ABSTRACT FROM AUTHOR]

In the process of neuronal development, the protein Purα (encoded by the PURA gene) is essential for neuronal proliferation, dendritic maturation, and the transportation of mRNA to translation sites. Mutations in the PURA gene may alter normal brain development and impair neuronal function, contributing to developmental delays and seizures. Recently, PURA syndrome is described as developmental encephalopathy with or without epilepsy, neonatal hypotonia, feeding difficulties, global developmental delay, and severe intellectual disability. In our study, we aimed to perform a genetic analysis by whole exome sequencing (WES) in a Tunisian patient presented with developmental and epileptic encephalopathy to provide a molecular explanation for the developed phenotype. We collected, also, clinical data of all PURA p.(Phe233del) patients reported yet and compared the clinical features with those of our patient. Results revealed the presence of the known PURA c.697_699del, p.(Phe233del) variant. Our studied case shares some clinical features including hypotonia, feeding difficulties, severe developmental delay, epilepsy, and language delay (nonverbal) but presents a radiological finding undescribed before. Our finding defines and expands the phenotypic and genotypic spectrum of the PURA syndrome supporting the absence of reliable genotype–phenotype correlations and the existence of a highly variable, wide‐ranging clinical spectrum. [ABSTRACT FROM AUTHOR]

Background: The International Parkinson and Movement Disorders Society (MDS) set up a working group on pediatric movement disorders (MDS Task Force on Pediatrics) to generate recommendations to guide the transition process from pediatrics to adult health care systems in patients with childhood‐onset movement disorders. Methods: To develop recommendations for transitional care for childhood onset movement disorders, we used a formal consensus development process, using a multi‐round, web‐based Delphi survey. The Delphi survey was based on the results of the scoping review of the literature and the results of a survey of MDS members on transition practices. Through iterative discussions, we generated the recommendations included in the survey. The MDS Task Force on Pediatrics were the voting members for the Delphi survey. The task force members comprise 23 child and adult neurologists with expertise in the field of movement disorders and from all regions of the world. Results: Fifteen recommendations divided across four different areas were made pertaining to: (1) team composition and structure, (2) planning and readiness, (3) goals of care, and (4) administration and research. All recommendations achieved consensus with a median score of 7 or greater. Conclusion: Recommendations on providing transitional care for patients with childhood onset movement disorders are provided. Nevertheless several challenges remain in the implementation of these recommendations, related to health infrastructure and the distribution of health resources, and the availability of knowledgeable and interested practitioners. Research on the influence of transitional care programs on outcomes in childhood onset movement disorders is much needed. [ABSTRACT FROM AUTHOR]

Epilepsy is a neurological disorder, characterized by intractable seizures with severe consequences. To predict these seizures, electroencephalogram (EEG) data has to be collected in a continuous manner. EEG signals are recorded through several electrodes fixed on the scalp that cannot be worn by a patient in a continuous manner. This paper presents a novel patient-specific approach to identify and select the most pertinent EEG channels (i.e., electrodes) without prior expert knowledge. The approach is based on a cascading deep learning model consisting of convolution blocks and attention layers. The data collected by the selected EEG channels is processed by a novel deep learning model consisting of a convolutional neural network and a gated recurrent neural network to predict epileptic seizures. Our work supports EEG sensors with a reduced number of electrodes that could be easily worn by patients for longer periods of time. The proposed approach is validated using the CHB-MIT benchmark. The obtained results show that our channel selection model outperforms existing approaches (e.g., Random Forest) by selecting fewer EEG channels. Thus, it is possible to use only two or three EEG channels for effective patient-specific epileptic seizure prediction. Experimental results also demonstrate that our selection approach reduces the prediction time. • It is possible to use only two or three EEG channels for epileptic seizure prediction. • An attention-based neural network assigns importance scores to EEG channels. • Channel selection and the number of selected channels are patient-specific. • The CHB-MIT database is used to validate the proposed EEG channel selection approach. • The attention-based approach selects EEG channels without prior expert knowledge. [ABSTRACT FROM AUTHOR]

Epilepsy surgery is the treatment of choice for patients with drug‐resistant seizures. A timely evaluation for surgical candidacy can be life‐saving for patients who are identified as appropriate surgical candidates, and may also enhance the care of nonsurgical candidates through improvement in diagnosis, optimization of therapy, and treatment of comorbidities. Yet, referral for surgical evaluations is often delayed while palliative options are pursued, with significant adverse consequences due to increased morbidity and mortality associated with intractable epilepsy. The Surgical Therapies Commission of the International League Against Epilepsy (ILAE) sought to address these clinical gaps and clarify when to initiate a surgical evaluation. We conducted a Delphi consensus process with 61 epileptologists, epilepsy neurosurgeons, neurologists, neuropsychiatrists, and neuropsychologists with a median of 22 years in practice, from 28 countries in all six ILAE world regions. After three rounds of Delphi surveys, evaluating 51 unique scenarios, we reached the following Expert Consensus Recommendations: (1) Referral for a surgical evaluation should be offered to every patient with drug‐resistant epilepsy (up to 70 years of age), as soon as drug resistance is ascertained, regardless of epilepsy duration, sex, socioeconomic status, seizure type, epilepsy type (including epileptic encephalopathies), localization, and comorbidities (including severe psychiatric comorbidity like psychogenic nonepileptic seizures [PNES] or substance abuse) if patients are cooperative with management; (2) A surgical referral should be considered for older patients with drug‐resistant epilepsy who have no surgical contraindication, and for patients (adults and children) who are seizure‐free on 1–2 antiseizure medications (ASMs) but have a brain lesion in noneloquent cortex; and (3) referral for surgery should not be offered to patients with active substance abuse who are noncooperative with management. We present the Delphi consensus results leading up to these Expert Consensus Recommendations and discuss the data supporting our conclusions. High level evidence will be required to permit creation of clinical practice guidelines. [ABSTRACT FROM AUTHOR]

Clinical practice guidelines (CPGs) are statements that provide evidence‐based recommendations aimed at optimizing patient care. However, many other documents are often published as "guidelines" when they are not; these documents, although also important in clinical practice, are usually not systematically produced following rigorous processes linking the evidence to the recommendations. Specifically, the International League Against Epilepsy (ILAE) guideline development toolkit aims to ensure that high‐quality CPGs are developed to fill knowledge gaps and optimize the management of epilepsy. In addition to adhering to key methodological processes, guideline developers need to consider that effective CPGs should lead to improvements in clinical processes of care and health care outcomes. This requires monitoring the effectiveness of epilepsy‐related CPGs and interventions to remove the barriers to epilepsy CPG implementation. This article provides an overview of what distinguishes quality CPGs from other documents and discusses their benefits and limitations. We summarize the recently revised ILAE CPG development process and elaborate on the barriers and facilitators to guideline dissemination, implementation, and adaptation. [ABSTRACT FROM AUTHOR]

The International League Against Epilepsy (ILAE) Task Force on Nosology and Definitions proposes a classification and definition of epilepsy syndromes in the neonate and infant with seizure onset up to 2 years of age. The incidence of epilepsy is high in this age group and epilepsy is frequently associated with significant comorbidities and mortality. The licensing of syndrome specific antiseizure medications following randomized controlled trials and the development of precision, gene‐related therapies are two of the drivers defining the electroclinical phenotypes of syndromes with onset in infancy. The principal aim of this proposal, consistent with the 2017 ILAE Classification of the Epilepsies, is to support epilepsy diagnosis and emphasize the importance of classifying epilepsy in an individual both by syndrome and etiology. For each syndrome, we report epidemiology, clinical course, seizure types, electroencephalography (EEG), neuroimaging, genetics, and differential diagnosis. Syndromes are separated into self‐limited syndromes, where there is likely to be spontaneous remission and developmental and epileptic encephalopathies, diseases where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. The emerging class of etiology‐specific epilepsy syndromes, where there is a specific etiology for the epilepsy that is associated with a clearly defined, relatively uniform, and distinct clinical phenotype in most affected individuals as well as consistent EEG, neuroimaging, and/or genetic correlates, is presented. The number of etiology‐defined syndromes will continue to increase, and these newly described syndromes will in time be incorporated into this classification. The tables summarize mandatory features, cautionary alerts, and exclusionary features for the common syndromes. Guidance is given on the criteria for syndrome diagnosis in resource‐limited regions where laboratory confirmation, including EEG, MRI, and genetic testing, might not be available. [ABSTRACT FROM AUTHOR]

Background: 8q21.11 microdeletion syndrome is a rare chromosomal disorder characterized by recurrent dysmorphic features, a variable degree of intellectual disability and ocular, cardiac and hand/feet abnormalities. To date, ZFHX4 is the only candidate gene implicated in the ocular findings. In this study, we evaluated a patient with a de novo 8q21.13–21.3 deletion to define a new small region of overlap (SRO) for this entity. Methods: We conducted a clinical evaluation and comparative genomic hybridization (CGH) 4x44K microarrays in a patient with de novo unbalanced translocation t(8;16)(q21; q11.2). Results: The case, a 6‐year‐old boy, presented dysmorphic features including an elongated face, brachycephaly with a high forehead, an underdeveloped ala, thin upper lip, micrognathia, low‐set ears, hypotonia, mild intellectual disability, cortical atrophy with thin corpus callosum defect, and an atrial septal defect. No ocular abnormalities were found. Microarray analysis revealed a 9.6 Mb interstitial 8q21.11–21.3 deletion, not including the ZFHX4 gene. This microdeletion was confirmed in our patient through qPCR analysis, and both parents had a normal profile. Alignment analysis of our case defined a new SRO encompassing five genes. Among them, the HEY1 gene is involved in the embryonic development of the heart, central nervous system, and vascular system. Hrt1/Hey1 null mice show perinatal lethality due to congenital malformations of the aortic arch and its branch arteries. HEY1 has also been linked to the maintenance of neural stem cells, inhibition of oligodendrocyte differentiation, and myelin gene expression. Conclusion: HEY1 is a candidate gene for both neurological and cardiac features of the 8q21.11 microdeletion syndrome and might, therefore, explain specific components of its pathophysiology. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic leads to disruptions of health services worldwide. To evaluate the particular impact on neurological services a rapid review was conducted. Methods: Studies reporting the provision of neurological services during the pandemic and/or adopted mitigation strategies were included in this review. PubMed and World Health Organization's (WHO) COVID-19 database were searched. Data extraction followed categories used by WHO COVID-19 pulse surveys and operational guidelines on maintaining essential health services during COVID-19. Findings: The search yielded 1101 articles, of which 369 fulfilled eligibility criteria, describing data from 210,419 participants, being adults (81%), children (11.4%) or both (7.3%). Included articles reported data from 105 countries and territories covering all WHO regions and World Bank income levels (low income: 1.9%, lower middle: 24.7%, upper middle: 29.5% and high income; 44.8%). Cross-sectoral services for neurological disorders were most frequently disrupted (62.9%), followed by emergency/acute care (47.1%). The degree of disruption was at least moderate for 75% of studies. Travel restrictions due to lockdowns (81.7%) and regulatory closure of services (65.4%) were the most commonly reported causes of disruption. Authors most frequently described telemedicine (82.1%) and novel dispensing approaches for medicines (51.8%) as mitigation strategies. Evidence for the effectiveness of these measures is largely missing. Interpretation: The COVID-19 pandemic affects all aspects of neurological care. Given the worldwide prevalence of neurological disorders and the potential long-term neurological consequences of COVID-19, service disruptions are devastating. Different strategies such as telemedicine might mitigate the negative effects of the pandemic, but their efficacy and acceptability remain to be seen. [ABSTRACT FROM AUTHOR]

Abstract: An increasing number of genomic variations are no more regarded as harmless changes in protein coding sequences or as genetic polymorphisms. Studying the impact of these variations on mRNA metabolism became a central issue to better understand the biological significance of disease. We describe here a severe congenital muscular dystrophy (CMD) with lumbar scoliosis and respiratory complications in a patient, who died at the age of 10. Despite a poor linkage to any form of CMD, total deficiency of laminin-α2 rather suggested the occurrence of an MDC1A form. Extensive analysis of LAMA2 gene revealed two novel mutations: a (8007delT) frameshift deletion in exon 57, and a de novo 7nt deletion in intron 17. Using an ex vivo approach, we provided strong evidence that the intron mutation is responsible for complete exon 17 skipping. The mutations are in trans and they each generate a nonsense mRNA potentially elicited to degradation by NMD. We further discuss the impact of mRNA alterations on the subtle phenotypic discrepancies. [Copyright &y& Elsevier]

Background: Developmental and epileptic encephalopathies (DEE) are chronic neurological conditions where epileptic activity contributes to the progressive disruption of brain function, frequently leading to impaired motor, cognitive and sensory development.Patients and Methods: The present study reports a clinical investigation and a molecular analysis by Next Generation Sequencing (NGS) of a large consanguineous family comprising several cases of developmental and epileptic encephalopathy. Bioinformatic prediction and molecular docking analysis were also carried out.Results: The majority of patients in our studied family had severe developmental impairments, early-onset seizures, brain malformations such as cortical atrophy and microcephaly, developmental delays and intellectual disabilities. The molecular investigations revealed a novel homozygous variant c.1411G>A (p.Gly471Arg) in the GRM7 gene which was segregating with the disease in the family. Bioinformatic tools predicted its pathogenicity and docking analysis revealed its potential effects on mGlu7 protein binding to its ligand.Conclusion: Our results contribute to a better understanding of the impact of GRM7 variants for the newly described associated phenotype. [ABSTRACT FROM AUTHOR]

Seizures are the most common neurological emergency in the neonatal period and in contrast to those in infancy and childhood, are often provoked seizures with an acute cause and may be electrographic‐only. Hence, neonatal seizures may not fit easily into classification schemes for seizures and epilepsies primarily developed for older children and adults. A Neonatal Seizures Task Force was established by the International League Against Epilepsy (ILAE) to develop a modification of the 2017 ILAE Classification of Seizures and Epilepsies, relevant to neonates. The neonatal classification framework emphasizes the role of electroencephalography (EEG) in the diagnosis of seizures in the neonate and includes a classification of seizure types relevant to this age group. The seizure type is determined by the predominant clinical feature. Many neonatal seizures are electrographic‐only with no evident clinical features; therefore, these are included in the proposed classification. Clinical events without an EEG correlate are not included. Because seizures in the neonatal period have been shown to have a focal onset, a division into focal and generalized is unnecessary. Seizures can have a motor (automatisms, clonic, epileptic spasms, myoclonic, tonic), non‐motor (autonomic, behavior arrest), or sequential presentation. The classification allows the user to choose the level of detail when classifying seizures in this age group. [ABSTRACT FROM AUTHOR]

Tuberous sclerosis complex (TSC) syndrome is a neurocutaneous syndrome that affects the brain, skin, and kidneys that has an adverse impact on the patient's health and quality of life. There have been several recent advances that elucidate the genetic complex of this disorder that will help understand the basic neurobiology of this disorder. We report a Tunisian patient with clinical manifestations of TSC syndrome. We investigated the causative molecular defect in this patient using PCR followed by direct sequencing. Subsequently, in silico studies and mRNA analysis were performed to study the pathogenicity of the new variation found in the TSC2. Bioinformatics tools predicted that the novel mutation c.1444‐2A>T have pathogenic effects on splicing machinery. RT‐PCR followed by sequencing revealed that the mutation c.1444‐2A>T generates two aberrant transcripts. The first, with exon 15 skipping, is responsible for the loss of 52 amino acids, which causes the production of an aberrant protein isoform. The second, with the inclusion of 122 nucleotides of intron 14, is responsible for the creation of new premature termination codons (TGA), which causes the production of a truncated TSC2 protein. This study highlighted the clinical features of a Tunisian patient with TSC syndrome and revealed a splicing mutation c.1444‐2A>T within intron 14 of TSC2 gene, which is present for the first time using Sanger sequencing approach, as a disease‐causing mutation in a Tunisian patient with TSC syndrome. [ABSTRACT FROM AUTHOR]

Background: Chanarin-Dorfman syndrome (CDS) is a rare syndromic disease related to an accumulation of triacylglycerol in most organs. The aim of our study was to investigate various organs in a large series of CDS patients.Results: We report for the first time thyroid function impairment in CDS. Among 12 investigated patients, 7 showed thyroid function impairment. All of them were over 30 of age. The 5 remaining investigated patients with normal thyroid function were under 30. Thyroid loss of function is an unknown clinical feature of CDS that could gradually develop with age. Thyroid ultrasound showed an abnormal aspect in all investigated patients (6 with thyroid impairment and 3 with normal thyroid function). Cervical MRI done in 2 patients with thyroid impairment showed fat infiltration of thyroid parenchyma. Audiogram carried out in 8 of our patients showed sensorineural hearing impairment in all patients, although only 2 patients suffered from clinical hypoacusia. We also demonstrated that kidney could be a more commonly involved organ than previously reported in the literature. A poorly differentiated kidney parenchyma is a common feature in our series. One patient showed cerebellar atrophy and T2 hypersignal of brain's white matter in MRI. All patients carried the same founder mutation c.773(- 1)G > A in the ABDH5 gene.Discussion: Aside from the congenital ichthyosiform erythroderma, the most common symptom of CDS, in addition to other organs involvement frequently reported in the literature, we described thyroid dysfunction, an unreported feature, probably related to the lipid infiltration of the thyroid parenchyma. The association found between age and hypothyroidism in CDS patients could explain the gradually development of thyroid disease with age.Conclusion: We reported a thyroid dysfunction and unreported ultrasonographic aspects of kidneys and cerebral MRI in CDS patients.Methods: We performed clinical analyses in 15 patients in whom thyroid, liver, ocular, kidney, skeletal muscle and neurological involvement were explored. Genetic and molecular explorations were performed by direct sequence analysis. Software SPSS, Fisher's exact test and ANOVA were used for statistical analyses. [ABSTRACT FROM AUTHOR]

Congenital heart defects represent a characteristic part of several genetic syndromes associated with chromosomal abnormalities such as 22q11.2 deletion syndrome; many genes located in this locus, mainly TBX1 , are candidate genes for congenital heart defects. In our cohort of 27 subjects with congenital heart defect, both karyotype analysis and Fluorescence in situ hybridization (FISH) were performed. The TBX1 gene was sequenced in patients lacking chromosomal abnormalities. FISH analysis showed a de novo 22q11.2 deletion in two patients. The screening of TBX1 coding sequence identified a novel missense mutation c.569C > A (p.P190Q) in six unrelated patients and detected two associated known single nucleotide polymorphisms; the c.664C > T (rs2301558) in three patients and the c.420T > C (p.Phe140 Phe) (rs41298814) in one patient. Bioinformatic tools show that the novel missense mutation c.569C > A could modify the function and the stability of the TBX1 protein. The c.569C > A mutation was not found in 50 healthy controls. Ours results suggest a deleterious role of the c.569C > A mutation and strengthen the hypothesis that this mutation might be responsible for the same phenotype spectrum as the 22q11.2 deletion syndrome. [ABSTRACT FROM AUTHOR]

Introduction West syndrome is a rare epileptic encephalopathy of early infancy, characterized by epileptic spasms, hypsarrhythmia, and psychomotor retardation beginning in the first year of life. Methods The present study reports the clinical, molecular and bioinformatic investigation in the three studied West patients. Results The results revealed a complex genotype with more than one mutation in each patient including the known mutations c.1910C > G (P2, P3); c.2372A > C in P3 and c.2395C > G in P1 and novel variants including c.616 G > A, shared by the three patients P1, P2 and P3; c.1403G > C shared by P2 and P3 and c.2288A > G in patient P1. Conclusions All the mutations were at somatic mosaic state and were de novo in the patients except ones (c.2372A > C). To our knowledge; the somatic mosaic state is described for the first time in patients with West syndrome. Five identified mutations were located in the C-terminal domain of the protein, while the novel mutation (c.616 G > A) was in the catalytic domain. Bioinformatic tools predicted that this latter is the most pathogenic substitution affecting 3D protein structure and the secondary mRNA structure. Complex genotype composed of different combinations of mutations in each patient seems to be related to the phenotype variability. [ABSTRACT FROM AUTHOR]

Rett syndrome is an X-linked neurodevelopmental disorder, primarily caused by MECP2 mutations. In this study, clinical, molecular and bioinformatics analyses were performed in Rett patients to understand the relationship between MECP2 mutation type and the clinical severity. Two double MeCP2 mutations were detected: a novel one (p.G185 V in cis with p.R255X) in P1 and a known one (p.P179 S in cis with p.R255X) in P2. Besides, a novel synonymous mutation (c.807C>T; p.G269G), which could affect mRNA splicing, was identified in P3. The results from clinical severity analysis have shown that P1 was more severely affected than P2 with CSS being 35 and 14, respectively. Therefore, the phenotypic variability in P1 and P2 could be explained by the potential pathogenic effect of the RTT-causing missense mutation p.G185 V in the AT-hook1. In conclusion, clinical, molecular, and in silico investigations in the studied patients have been proven to be substantial for the genotype-phenotype correlation. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to examine the effect of a group-based task oriented skills training program on motor and physical ability for children with DCD. It was also investigated if there was an effect on fine motor and handwriting tasks that were not specifically practiced during the training program. Forty-one children aged 6-10years took part in this study. Children were assigned to three groups: an experimental training group consisting of 14 children with DCD, a control non-training group consisted of 13 children with DCD and a control non-training group consisting of 14 typically developed children. The measurements included were, the Movement Assessment Battery for Children (MABC), the Modified Agility Test (MAT), the Triple Hop Distance (THD), the 5 Jump-test (5JT) and the Handwriting Performance Test. All measures were administered pre and post an 8-week training program. The results showed that 10 children of the DCD training-group improved their performance in MABC test, attaining a score above the 15th percentile after their participation in the training program. DCD training-group showed a significant improvement on all cluster scores (manual dexterity (t (13)=5.3, p<.001), ball skills (t (13)=2.73, p<.05) and balance (t (13)=5.13, p<.001). Significant performance improvements were also found in MAT, THD, 5JT (t (13)=-4.55; p<.01), handwriting quality (t (12)=-2.73; p<.05) and speed (t (12)=-4.2; p<.01) after the training program. In conclusion, improvement in both practiced and non-practiced skills, in the training program, may reflect improvement in motor skill but also transfer to other skills. [ABSTRACT FROM AUTHOR]

Introduction X-linked adrenoleukodystrophy is a neurodegenerative recessive disorder that affects the brain white matter and associated with adrenal insufficiency. It is characterized by an abnormal function of the peroxisomes, which leads to an accumulation of the Very Long Chain Fatty Acids (VLCFA) in plasma and tissues, especially in the cortex of the adrenal glands and the white matter of the central nervous system. Mutations in the ABCD1 gene affect the function of the encoded protein ALDP, an ATP-binding cassette transporter located in the peroxisomal membrane protein. Patients and methods The present study reports the clinical, biochemical and molecular investigation in a Tunisian family with two affected males with childhood cerebral adrenoleukodystrophy. Results The ABCD1 gene sequencing indicated a novel hemizygous missense mutation c.947A > C (p.Gln316Pro) in the exon 2 of the ABCD1 gene in the patients, their mother and their sisters. This missense variation was predicted to be possibly damaging by the PolyPhen and SIFT prediction software. Although presence of the same mutation c.947A > C in both siblings, they present different clinical signs. Conclusions Based on the disease's progress, the clinical signs and biochemical aspects between the two siblings, we demonstrate that there is no correlation genotype–phenotype. [ABSTRACT FROM AUTHOR]

Interventions based on everyday motor skills have been developed to be effective in children with developmental coordination disorder (DCD). The purpose of the present study was to examine the effects of motor skill training on exercise tolerance and cardiorespiratory fitness in children with DCD. Children were assigned to 3 groups: an experimental training group comprising 14 children with DCD, a control nontraining group comprising 13 children with DCD, and a control nontraining group comprising 14 typically developed children. All participants were tested twice with an interval of 8-weeks on a cardiopulmonary exercise test, pulmonary function testing, and a 6-min walk test. After the training program the maximal power output was significantly increased for DCD group at anaerobic threshold ( p < 0.05) and at peak level (maximal oxygen uptake, p < 0.001). Improvement in power output was more pronounced at the anaerobic threshold ( t (13) = −5.21, p < 0.001) than at the maximal intensity (maximal oxygen uptake, t (13) = −3.08, p < 0.01) in the DCD training group. Children with DCD that participated in the training program improved their walking distance ( t (13) = −9.08, p < 0.001), had a higher maximum heart rate ( t (13) = −3.41, p < 0.01), and reduced perceived exertion ( t (13) = 2.75, p < 0.05). The DCD nontraining group and the typically developed group did not change on any of the measures. In conclusion, training delayed reaching the anaerobic threshold and improved aerobic endurance and exercise tolerance in children with DCD. [ABSTRACT FROM AUTHOR]

Rett syndrome is a monogenic X-linked dominant neurodevelopmental disorder related to mutation in MECP2, which encodes the methyl-CpG–binding protein MeCP2. The aim of this study was to search for mutations of MECP2 gene in Tunisian Rett patients and to evaluate the impact of the found variants on structural and functional features of MeCP2. The result of mutation analysis revealed that 3 Rett patients shared the same novel heterozygous point mutation c.175G>C (p.A59P). The p.A59P mutation was located in a conserved amino acid in the N-terminal segment of MeCP2. This novel mutation confers a phenotypic variability with different clinical severity scores (3, 8, and 9) and predicted by Sift and PolyPhen to be damaging. Modeling results showed that p.A59P adds 2 hydrogen bonds and changes the structural conformation of MeCP2 with a significant root mean square deviation value (9.66 Å), suggesting that this mutation could probably affect the conformation, function and stability of MeCP2. [ABSTRACT FROM AUTHOR]

• In total, 1123 neurologists from 27 countries participated. • Many respondents reported to discuss SUDEP only rarely. • The propensity to tell all patients was higher among those with epilepsy fellowship. To investigate the opinions and attitudes of neurologists on the counseling about sudden unexpected death in epilepsy (SUDEP) worldwide. Practicing neurologists from around the world were invited to participate in an online survey. On February 18th, 2021, we emailed an invitation including a questionnaire (using Google-forms) to the lead neurologists from 50 countries. The survey anonymously collected the demographic data of the participants and answers to the questions about their opinions and attitudes toward counseling about SUDEP. In total, 1123 neurologists from 27 countries participated; 41.5% of the respondents reported they discuss the risk of SUDEP with patients and their care-givers only rarely. Specific subgroups of patients who should especially be told about this condition were considered to be those with poor antiseizure medication (ASM) adherence, frequent tonic-clonic seizures, or with drug-resistant epilepsy. The propensity to tell all patients with epilepsy (PWE) about SUDEP was higher among those with epilepsy fellowship. Having an epilepsy fellowship and working in an academic setting were factors associated with a comfortable discussion about SUDEP. There were significant differences between the world regions. Neurologists often do not discuss SUDEP with patients and their care-givers. While the results of this study may not be representative of practitioners in each country, it seems that there is a severe dissociation between the clinical significance of SUDEP and the amount of attention that is devoted to this matter in daily practice by many neurologists around the world. [ABSTRACT FROM AUTHOR]

Intellectual disability (ID) often co-occurs with other neurologic phenotypes making molecular diagnosis more challenging particularly in consanguineous populations with the co-segregation of more than one ID-related gene in some cases. In this study, we investigated the phenotype of three patients from a large Tunisian family with significant ID phenotypic variability and microcephaly and performed a clinical exome sequencing in two cases. We identified, within the first branch, a homozygous variant in the TRAPPC9 gene (p.Arg472Ter) in two cases presenting severe ID, absent speech, congenital/secondary microcephaly in addition to autistic features, supporting the implication of TRAPPC9 in the "secondary" autism spectrum disorders and congenital microcephaly. In the second branch, we identified a homozygous variant (p.Lys189ArgfsTer15) in the CDK5RAP2 gene associated with an heterozygous TRAPPC9 variant (p.Arg472Ter) in one case harbouring primary hereditary microcephaly (MCPH) associated with an inter-hypothalamic adhesion, mixed hearing loss, selective thinning in the retinal nerve fiber layer and parafoveal ganglion cell complex, and short stature. Our findings expand the spectrum of the recently reported neurosensorial abnormalities and revealed the variable phenotype expressivity of CDK5RAP2 defect. Our study highlights the complexity of the genetic background of microcephaly/ID and the efficiency of the exome sequencing to provide an accurate diagnosis and to improve the management and follow-up of such patients. • The diagnosis of intellectual disability is more challenging within families with complex consanguinity loops. • TRAPPC9 is associated with secondary Autism spectrum disorder and congenital microcephaly. • CDK5RAP2 is involved in the ocular and cochlear development, as well as the hypothalamic nuclear separation at the midline. • Selective thinning in retinal nerve fiber layer and parafoveal ganglion cell complex was added to CDK5RAP2 defect. [ABSTRACT FROM AUTHOR]

Charcot-Marie-Tooth (CMT) disease constitutes a clinically and genetically heterogeneous group of hereditary neuropathies characterized by progressive muscular and sensory loss in the distal extremities with chronic distal weakness, deformation of the feet, and loss of deep tendon reflexes. CMT4H is an autosomal recessive demyelinating subtype of CMT, due to mutations in FGD4/FRABIN, for which nine mutations are described to date. In this study, we describe three patients from a consanguineous Tunisian family, presenting with severe, early onset, slowly progressive, autosomal recessive demyelinating CMT, complicated by mild to severe kyphoscoliosis, consistent with CMT4H. In these patients, we report the identification of a novel homozygous frameshift mutation in FGD4: c.514_515insG; p.Ala172Glyfs*27. Our study reports the first mutation identified in FGD4 in Tunisian patients affected with CMT. It further confirms the important clinical heterogeneity observed in patients with mutations in FGD4 and the lack of phenotype/genotype correlations in CMT4H. Our results suggest that FGD4 should be screened in other early-onset CMT subtypes, regardless of the severity of the phenotype, and particularly in patients of consanguineous descent. In Tunisians, as in other populations with high consanguinity rates, screening of genes responsible for rare autosomal recessive CMT subtypes should be prioritized. [ABSTRACT FROM AUTHOR]

Recessive mutations of CAPN3 gene are reported to be responsible for limb girdle muscular dystrophy type 2A (LGMD2A). In all, 15-25% of intronic nucleotide changes identified in this gene were investigated by in silico analysis, but occasionally supported by experimental data or reported in some cases as a polymorphism. We report here genetic and transcriptional analyses in three Tunisian patients belonging to the same consanguineous family sharing the same mutation c.1194-9 A>G and Alu repeats insertion in intron 7 of CAPN3 gene. Reverse transcriptase-PCR experiments performed on total RNA from the patient's muscle biopsy showed retention of the eight last nucleotides of intron 9 in the CAPN3 transcript lacking the first seven exons. Our results provide evidence regarding the potential involvement of Alu elements in aberrant processing of pre-mRNA owing to the disruption of pre-existing intronic splicing regulatory elements. We also demonstrated variable mRNA alternative splicing among tissues and between LGMD2A patients. A deep intronic variation and rearrangement have been reported in the literature as causing genetic diseases in humans. However, this is the first report on a potential pathogenic CAPN3 gene mutation resulting from an Alu insertion. [ABSTRACT FROM AUTHOR]

Abstract: Rett syndrome is an X-linked dominant disorder caused frequently by mutations in the methyl-CpG-binding protein 2 gene (MECP2). Rett patients present an apparently normal psychomotor development during the first 6–18months of life. Thereafter, they show a short period of developmental stagnation followed by a rapid regression in language and motor development. The aim of this study was to perform a mutational analysis of the MECP2 gene in a classical Rett patient by sequencing the corresponding gene and modeling the found variants. The results showed the presence of a double-mutation: a new and de novo mutation c.535C>T (p.P179S) and the common c.763C>T (p.R255X) transition of the MECP2 gene. The p.P179S mutation was located in a conserved amino acid in CRIR domain (corepressor interacting region). Modeling results showed that the P179S transition could change local electrostatic properties by adding a negative charge due to serine hydroxyl group of this region of MeCP2 which may affect the function and stability of the protein. The p.R255X mutation is located in TRD-NLS domain (transcription repression domain-nuclear localization signal) of MeCP2 protein. [Copyright &y& Elsevier]

Abstract: Dravet syndrome (DS), previously known as severe myoclonic epilepsy of infancy, is one of the most severe forms of childhood epilepsy. DS is caused by a mutation in the neuronal voltage-gated sodium-channel alpha-subunit gene (SCN1A). However, 25–30% of patients with DS are negative for the SCN1A mutation screening, suggesting that other molecular mechanisms may account for these disorders. Recently, the first case of DS caused by a mutation in the neuronal voltage-gated sodium-channel beta-subunit gene (SCN1B) was also reported. In this report we aim to make the molecular analysis of the SCN1A and SCN1B genes in two Tunisian patients affected with DS. The SCN1A and SCN1B genes were tested for mutations by direct sequencing. No mutation was revealed in the SCN1A and SCN1B genes by sequencing analyses. On the other hand, 11 known single nucleotide polymorphisms were identified in the SCN1A gene and composed a putative disease-associated haplotype in patients with DS phenotype. One of the two patients with putative disease-associated haplotype in SCN1A had also one known single nucleotide polymorphism in the SCN1B gene. The sequencing analyses of the SCN1A gene revealed the presence of a putative disease-associated haplotype in two patients affected with Dravet syndrome. [Copyright &y& Elsevier]

LGMD (limb-girdle muscular dystrophy) and CMD (congenital muscular dystrophy) are two common forms of neuromuscular disorders which are distinguishable by their age of onset but with probably a similar underlying pathway. In the present study, we report immunohistochemical, Western-blot and genetic analyses in a large consanguineous Tunisian family with two branches, including seven patients sharing similar LGMD2 phenotype in one branch and one CMD patient in the other branch. Linkage analyses were compatible with the LGMD2A locus in one branch and the MDC1A (muscular dystrophy congenital type 1A) locus in the other branch. This result was supported by deficiency in merosin and calpain3 in the CMD patient and LGMD patients respectively. Mutation analysis revealed two distinct mutations: a c.8005delT frameshift deletion in exon 56 of the LAMA2 (laminin-α2) gene (MDC1A) was found in the CMD patient and a new homozygous mutation c.1536+1G>T in the donor splice site of intron 12 of the CAPN3 (calpain3) gene (LGMD2A) was found in the LGMD patients. RT-PCR (reverse transcription-PCR) performed on total RNA from a LGMD2A patient's muscle biopsy showed complete retention of intron 12 in CAPN3 cDNA, generating a PTC (premature termination codon) that potentially elicits degradation of the nonsense mRNA by NMD (nonsensemediated mRNA decay). Our results indicate that mRNA analysis is necessary to clarify the primary effect of genomic mutations on splicing efficiency that alters mRNA processing and expression level. [ABSTRACT FROM AUTHOR]

Cytochrome c oxidase is an essential component of the mitochondrial respiratory chain that catalyzes the reduction of molecular oxygen by reduced cytochrome c. In this study, the authors report the second mutation associated with Leigh syndrome in the blood and buccal mucosa of 2 affected members of a Tunisian family. It was a novel heteroplasmic missense mitochondrial mutation at nucleotide 9478 in the gene specifying subunit III of cytochrome c oxidase substituting the valine at position 91 to alanine in a highly conserved amino acid. It was found with a high mutant load in tissues derived from endoderm (buccal mucosa) and mesoderm (blood). However, it was nearly absent in tissue derived from ectoderm (hair follicles). It was absent in 120 healthy controls, and PolyPhen analysis showed that the hydropathy index changed from +1.276 to +0.242, and the number of structures of the 3D protein decreased from 39 to 32. [ABSTRACT FROM AUTHOR]

Sensorineural hearing loss has been described in association with different mitochondrial multisystemic syndromes, often characterized by an important neuromuscular involvement. Until now, mutations in mitochondrial DNA, especially in the 12S rRNA, the tRNASer(UCN) and the tRNALeu(UUR) genes, were implicated in syndromic or non-syndromic hearing loss either as a primary cause or as predisposing factors. In the present study, we performed a whole mitochondrial genome screening in two unrelated Tunisian families with inherited hearing loss. Results showed the presence of a novel mutation in the mitochondrial 12S rRNA gene in the two probands of these two families who belong to two different haplogroups: L3 and H6a1. The m.735A>G mutation affects a conserved nucleotide of the mitochondrial 12S rRNA gene in primates and other species and had a conservation index of 78.5% (11/14). We also detected known polymorphisms and sic novel mitochondrial variants. The present study confirmed that the mitochondrial 12S rRNA gene is a hot spot for mutations associated with hearing impairment. [ABSTRACT FROM AUTHOR]

Generalized epilepsy with febrile seizure plus (GEFS+) is an autosomal dominant disorder. In the literature, 5 responsible genes were identified and 2 novel susceptibility loci for GEFS+ at 2p24 and 8p23-p21 were reported, indicating the genetic heterogeneity of this disorder. The aim of this report is to identify the responsible loci in a large affected Tunisian family by performing a 10cM density genome-wide scan. The highest multipoint logarithm of odds (LOD) score (1.04) was found for D5S407 in the absence of recombination. Two other interesting regions were found around marker D19S210 (LOD=0.799) and D7S484 (LOD=0.61) markers. To fine map these loci, additional markers in 2 regions on 5q13.3 and 7p14.2 were analyzed and positive LOD scores for both loci were obtained. Sequencing of the Sodium channel subunit beta-1 gene (SCN1B) (19q13.1) showed the absence of any causal mutation. Our findings emphasized the genetic heterogeneity of febrile seizures. [ABSTRACT FROM AUTHOR]

Rett syndrome is a severe disorder characterized by loss of acquired skills after a period of normal development in infant girls. It is caused mainly by mutations in the MECP2 gene. In this study, we reported mutations in the MECP2 gene in 7 Tunisian patients with classic Rett syndrome. The results showed the presence of a double mutation in 1 patient: p.R306C and c.1461+ 98insA, which create a new hypothetical polyadenylation site in the 3'UTR of the MECP2 gene. We also detected in another patient a new variant c.1461+ 92C>G in the 30UTR located previous to 34 bp from the polyadenylation site with a score of 4.085. This variation is located in a hypothetical splicing enhancer with a score of 1.96277 according to the ESE finder program. In the remaining 5 patients, we found 2 common mutations: p.T158M in 4 individuals and p.R168X in only 1 girl. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA defects were known to be associated with a wide spectrum of human diseases and patients might present a wide range of clinical features in various combinations. In the current study, we described a patient with psychomotor and neurodevelopmental delay, mild hyperintensity of posterior periventicular white matter, generalized clonic seizures, leukodystrophy, and congenital deafness. He also had tetraplegia, with central blindness and swallowing difficulty. Brain magnetic resonance imaging (MRI) showed involvement of the interpeduncular nucleus and central tegmental tract, white matter abnormalities, and cerebellar atrophy. A whole mitochondrial genome screening revealed the presence of 19 reported polymorphisms and an undescribed A to G mutation at nucleotide 8411 (p.M16V) affecting a conserved region of the mitochondrial adenosine triphosphatase (ATPase) 8 protein. This de novo mutation was detected in heteroplasmic form (97%) and was absent in 120 controls. Thus, the m.8411A>G mutation could strongly be associated with the disease in the tested patient. [ABSTRACT FROM AUTHOR]

Abstract: Leigh syndrome is a progressive neurodegenerative disorder occurring in infancy and childhood characterized in most cases by a psychomotor retardation, optic atrophy, ataxia, dystonia, failure to thrive, seizures and respiratory failure. In this study, we performed a systematic sequence analysis of mitochondrial genes associated with LS in Tunisian patients. We sequenced the encoded complex I units: ND2, ND3, ND4, ND5 and ND6 genes and the mitochondrial ATPase 6, tRNAVal, tRNALeu(UUR), tRNATrp and tRNALys genes in 10 unrelated patients with Leigh syndrome. We revealed the presence of 34 reported polymorphisms, nine novel nucleotide variants and two new mutations (T5523G and A5559G) in the tested patients. These two mutations were localized in two conserved regions of the tRNATrp and affect, respectively, the D-stem and the T-stem of the mitochondrial tRNA leading to a disruption of the secondary structure of this tRNA. SSP-PCR analysis showed that the T5523G and A5559G mutations were present with respective heteroplasmic rates of 66% and 43 %. We report here the first mutational screening of mitochondrial mutations in Tunisian patients with Leigh syndrome which described two novel mutations associated with this disorder. [Copyright &y& Elsevier]

Abstract: Ring chromosome 20 [r(20)] syndrome is a rare disease characterized by refractory epilepsy, moderate mental retardation and particular electroencephalographic disorder with non-convulsive status epilepticus. Here, we report a new case of r(20) syndrome in a 12 year old female who presented minimal dysmorphism, generalised tonic–clonic and absence seizures refractory to medical therapy and behavioural troubles. Among 20 cytogenetically analysed cells, 14 (70%) exhibited a 46,XX,r(20)(p13q13.3) karyotype and 6 (30%) showed a normal 46,XX caryotype. Interphasic FISH using centromeric probe of chromosome 20 detects the presence of a chromosome 20 monosomy in 7% and a duplicated ring chromosome 20 in 8% of studied cells. Metaphase FISH using chromosome 20 telomeric probes and specific probes of CHRNA4 and KCNQ2 genes detects the absence of any deletion in the ring chromosome 20. Clinical symptoms of r(20) syndrome are attributed to telomeric partial monosomy generated by ring chromosome and causing an haploinsufficiency of two epilepsy genes CHRNA4 and KCNQ2. However, our patient presents the typical epilepsy disorder but no detectable deletion in the ring chromosome 20. We speculate that clinical features of ring chromosome 20 syndrome are caused by low mosaicism of chromosome 20 monosomy caused by the loss of the ring chromosome 20. [Copyright &y& Elsevier]

Abstract: The mitochondrial tRNALeu(UUR) gene (MTTL) is a hot spot for pathogenic mutations that are associated with mitochondrial diseases with various clinical features. Among these mutations, the A3243G mutation was associated with various types of mitochondrial multisystem disorders, such as MIDD, MELAS, MERRF, PEO, hypertrophic cardiomyopathy, and a subtype of Leigh syndrome. We screened 128 Tunisian patients for the A3243G mutation in the mitochondrial tRNALeu(UUR) gene. This screening was carried out using PCR-RFLP with the restriction endonuclease ApaI. None of the 128 patients or the 100 controls tested were found to carry the mitochondrial A3243G mutation in the tRNALeu(UUR) gene in homoplasmic or heteroplasmic form. After direct sequencing of the entire mitochondrial tRNALeu(UUR) gene and a part of the mitochondrial NADH dehydrogenase 1, we found neither mutations nor polymorphisms in the MTTL1 gene in the tested patients and controls, and we confirmed the absence of the A3243G mutation in this gene. We also found a T3396C transition in the ND1 gene in one family with NSHL which was absent in the other patients and in 100 controls. Neither polymorphisms nor other mutations were found in the mitochondrial tRNALeu(UUR) gene in the tested patients. [Copyright &y& Elsevier]

L’ataxie-télangiectasie (AT) est une maladie génétique autosomique récessive rare, caractérisée par une ataxie cérébelleuse progressive, un déficit immunitaire, des télangiectasies oculo-cutanées et une forte prédisposition aux cancers à tout âge. L’association à une neuropathie périphérique n’est pas classique [1–3] . Nous rapportons les observations de 2 adolescents âgés de 18 et 16 ans suivis respectivement depuis l’âge de 11 et 6 ans pour une AT génétiquement confirmée. Au cours du suivi, les patients ont développé vers l’âge de 13 à 14 ans, en plus de l’ataxie cérébelleuse, un déficit distal qui a rendu la marche impossible sans double aide. L’examen clinique a objectivé en plus du syndrome cérébelleux statique et cinétique, un steppage bilatéral à la marche, une aréflexie tendineuse des membres inférieurs et une hyporéflexie aux membres supérieurs ainsi que des pieds creux sans troubles sensitifs associés. L’étude des vitesses de conduction nerveuses a mis en évidence une diminution des amplitudes sensitives et motrices au niveau des quatre membres. Les anomalies étaient plus marquées sur le versant moteur aux membres inférieurs et sensitif aux membres supérieurs. L’électromyographie retrouve des tracés pauvres voire simples accélérés aux membres inférieurs plus prononcés sur les muscles distaux. Aucune activité spontanée n’a été enregistrée. Ces anomalies électrophysiologiques témoignent d’une dégénérescence axonale majeure, sensitive et motrice, associée à l’atteinte cérébelleuse. Récemment, une étude tractographique sur des patients avec la mutation du gène responsable de l’AT a démontré l’implication non seulement du cervelet mais également d’autres circuits moteurs dans cette maladie. Les mécanismes physiopathologiques actuellement admis ne permettent pas d’expliquer la complexité du tableau électro-clinique présenté par nos patients. [ABSTRACT FROM AUTHOR]

L’épilepsie absence de l’enfant (EAE) est définie par des crises épileptiques faites d’une altération de la conscience à début et fin brusque, de durée brève concomitante à une décharge généralisée de pointe-ondes (PO) rythmiques à 3 Hz avec une activité de fond normale à l’électroencéphalogramme (EEG). Des aspects électriques moins typiques critiques et intercritques ont été décrits [1,2,3] . Nous rapportons les observations de 3 enfants d’un âge moyen de 6 ans ayant des crises d’absences typiques. À l’EEG de veille intercritique, le rythme de fond était normal mais des anomalies intercritiques à type de pointes frontales unilatérales et de bouffées de PO frontales bilatérales à bascule ont été objectivées chez les 3 patients. L’EEG critique a montré chez deux enfants des décharges généralisées de PO à 3 Hz précédées de PO frontales. Chez le troisième patient, les décharges débutaient en frontal puis se généralisaient et comportaient des PO et des polypointe-ondes à 3 Hz. Une mauvaise synchronisation durant la décharge a également été observée. Ces crises étaient résistantes à l’acide valproïque en monothérapie chez les trois patients et ont nécessité l’association de zarontin ou lamictal avec une évolution favorable. Ainsi, la présence de 2 voire 3 pointes par complexe, d’anomalies focales intercritiques, d’un début focal et d’une mauvaise synchronisation de la décharge ne doivent pas remettre en cause le diagnostic de l’EAE. [ABSTRACT FROM AUTHOR]

Objectives: Learning disorders are new clinical and therapeutic issues facing child psychiatrists. The problem of learning disorders becomes more complex in the presence of comorbid psychiatric disorders. In Tunisia, studies of psychiatric disorders comorbid in children with learning disorders remain missing. As well, this study was conducted to determine the comorbidity of psychiatric disorders and learning disorders and the factors associated with this comorbidity. Materials and Methods: The present study was cross-sectional, descriptive, comparative and analytical, involving 56 students with learning disorders (mean age = 10.43). These students benefited from a semi-structured child psychiatric interview based on the criteria of the DSM-VI-TR, in the presence of one or both parents. Similarly, individual, sociodemographic, family and perinatal data were collected using a predetermined form. Two groups of children were identified so: a first group of 24 children with learning disorders without psychiatric comorbidity and a second group of 32 students with learning disorders with psychiatric comorbidity. Data entry was performed using the epidemiology and statistics software SPSS. The descriptive study identified frequencies for qualitative variables and means for the quantitative variables. The analytical study was to compare the two groups in our sample, with a univariate analysis, search for possible correlations between the variable group and different variables. Results: Psychiatric comorbidity was found in 57% of cases. These were anxiety disorders in 34% of cases, enuresis in 25% of cases, language disorders in 20% of cases, major depressive episode in 7% of cases, oppositional defiant disorder in 6% of cases, attention deficit hyperactivity disorder in 6% of cases, tic disorder in 3.6% of cases and encopresis in 1.8% of cases. The psychiatric comorbidity was not correlated with any of the factors studied (individual, demographic, familial, perinatal). Conclusions: The results of this study are consistent with data from the literature and involve systematic search for psychiatric disorders in children with learning disorders. Likewise, pediatric psychiatrist should consider exploring the trail of learning disorders in any child with psychopathology. These children should receive a global care considering this comorbidity. [ABSTRACT FROM AUTHOR]