Genetic Neurological Disorders Research Articles

Эпидемиологические особенности распределения наследственных мозжечковых атаксий

Hereditary cerebellar ataxias (HCA) is a heterogeneous group of genetic neurological neurodegenerative diseases with a steadily progressive course. Ataxia is manifested by disturbed equilibrium, speech. Diseases of this group, as a rule, lead to disability of the patient. Advances in the field of molecular genetic research have made it possible to determine the form of HCA in accordance with the type of inheritance, and on this basis a classification of HCA has been formed. Monogenic (autosomal dominant, autosomal recessive, X-linked) and non-traditional types of inheritance of cerebellar ataxias (mitochondrial, expansion of trinucleotide repeats) are distinguished, sporadic forms with an unidentified or unknown type of transmission are also distinguished. Thus, HCA are classified into autosomal dominant spinocerebellar ataxias (SCA), they include 48 forms, some of which are polyglutamine SCA, and autosomal recessive, about 100 nosological entities. In addition, episodic cerebellar ataxia is also classified as an autosomal dominant ataxia. Among autosomal dominant ataxias, SCA3 or Machado-Joseph disease is the most common, followed by SCA2 and SCA6. However, in Russia, the prevalence is different. Among autosomal recessive ataxias, the most common is Friedreich’s ataxia, which also belongs to polyglutamine diseases. It should be taken into account that different methodological approaches lead to great heterogeneity and scattering of results in determining the prevalence of one or another form of hereditary ataxia both within the country and among the countries. The review presents current data on the prevalence of various forms of HCA in different regions of the world and populations. However, there is still a great deal of uncertainty regarding the overall prevalence of certain hereditary forms of cerebellar ataxia.

IDENTIFICATION OF NOVEL DRUG/LEAD MOLECULE FOR SCHIZOPHRENIA TARGETING RGS4 GENE THROUGH IN-SILICO ANALYSIS

Schizophrenia is a neuropsychiatric disorder that is caused by many factors including changes in the chemistry of the brain, structure of the brain, and genetic factors. The neuropathology of the disorder has been identified morphologically and physiologically through a number of parameters from a reduction in brain size and abnormalities in the neurotransmitter network affecting the brain to changes in the molecular composition of specific cell populations in the brain. Over a long period of time, clinicians and researchers have identified schizophrenia as a complex neurological genetic disorder as a result of the functionality of several susceptible genes. Various scientists are of the opinion that there are about 20 candidate genes that cause schizophrenia. Several genes like Dysbindin, Neuregulin, DAAO, G72, PRODH, COMT, and RGS4 have been proven to be the risk factors for schizophrenia disease. RGS4 was identified as a target gene for schizophrenia. Hence the present study was taken up to identify a Novel Drug/Lead Molecule from 12 selected drugs based on a bioinformatics approach for schizophrenia targeting the RGS4 gene. The genomics and proteomics approach of the RGS4 gene was carried out for nucleotide and protein sequences and the protein was modeled using SPDBV with 80% accuracy. The potential active site amino acids were predicted using molecular cavities based on energy and surface area and the protein was targeted using the best active site amino acids. The protein-ligand interactions were also performed using the Argus Lab engine with flexible docking. The data of the present study reveals that ziprasidone is showing maximum inhibition of the RGS4 gene among the 12 drugs selected for screening. It is thus concluded that ziprasidone with the lowest free energy and high affinity is the best inhibitor for the schizophrenia protein and hence it can be suggested for the treatment of schizophrenia.

Detection of Characteristic Phosphatidylcholine Containing Very Long Chain Fatty Acids in Cerebrospinal Fluid from Patients with X-Linked Adrenoleukodystrophy.

X-linked Adrenoleukodystrophy (X-ALD) is a rare genetic neurological disorder caused by a mutation of the ABCD1 gene that encodes a peroxisomal ABC protein ABCD1. ABCD1 has a role in transporting very long chain fatty acid (VLCFA)-CoA into the peroxisome for β-oxidation. ABCD1 dysfunction leads to reduced VLCFA β-oxidation and in turn increased VLCFA levels in the plasma and the cells of all tissues; these increased plasma levels have been used to diagnose X-ALD. It has been reported that plasma VLCFA is not correlated with the severity and disease phenotype of X-ALD. Therefore, we cannot predict the disease progression by the plasma VLCFA level. Cerebrospinal fluid (CSF) is constantly produced by brain, and thus levels of lipids containing VLCFA in CSF might be informative in terms of assessing X-ALD pathology. LC-MS/MS-based analysis showed that phosphatidylcholine (PC) containing VLCFA signals, such as PC 40 : 0(24 : 0/16 : 0), PC 42 : 0(26 : 0/16 : 0), PC 44 : 4(24 : 0/20 : 4) and PC 46 : 4(26 : 0/20 : 4) were characteristically detected only in the CSF from patients with X- ALD. In the present study, we analyzed limited number of patient's CSF samples (2 patients with X-ALD) due to the limitations of the availability for CSF samples from this rare disease. However, our finding would offer helpful information for studying the disease progression biomarkers in X-ALD. To our knowledge, this is the first report of analyzing lipids containing VLCFA in CSF from patients with X-ALD.

Bridging the Gap: Gene Therapy in a Patient With Spinal Muscular Atrophy Type 1.

Molecular therapies exploit the understanding of pathogenic mechanisms to reconstitute impaired gene function or manipulate flawed RNA expression. These therapies include (1) RNA interference by antisense oligonucleotides, (2) mRNA modification using small molecules, and (3) gene replacement therapy, the viral-mediated intracellular delivery of exogenous nucleic acids to reverse a genetic defect. Several molecular therapies are approved for treating spinal muscular atrophy (SMA), a recessive genetic disorder caused by survival motor neuron (SMN)1 gene alterations. SMA involves degeneration of lower motor neurons, which leads to progressive muscle weakness, hypotonia, and hypotrophy. Onasemnogene abeparvovec is a gene replacement therapy for SMA that uses adeno-associated virus delivery of functional SMN1 cDNA to motor neurons. Two other molecular therapies modulate SMN2 transcription: nusinersen, an antisense oligonucleotide, and risdiplam, a small molecule designed to modify faulty mRNA expression. The most suitable individualized treatment for SMA is not established. Here, we describe remarkable clinical improvement in a 4-month-old patient with SMA type 1 who received onasemnogene abeparvovec therapy. This case represents an explanatory bridge from bench to bedside with regard to therapeutic approaches for genetic disorders in neurology. Knowledge of the detailed mechanisms underlying genetic neurologic disorders, particularly monogenic conditions, is paramount for developing tailored therapies. When multiple disease-modifying therapies are available, early genetic diagnosis is crucial for appropriate therapy selection, highlighting the importance of early identification and intervention. A combination of drugs, each targeting unique genetic pathomechanisms, may provide additional clinical benefits.

Significance of Serum Oxidative and Antioxidative Status in Congenital Central Hypoventilation Syndrome (CCHS) Patients.

Congenital central hypoventilation syndrome (CCHS) is a rare neurological genetic disorder that affects sleep-related respiratory control. Currently, no drug therapy is available. In light of this, there is a need for lifelong ventilation support, at least during sleep, for these patients. The pathogenesis of several chronic diseases is influenced by oxidative stress. Thus, determining oxidative stress in CCHS may indicate further disorders in the course of this rare genetic disease. Liquid biopsies are widely used to assess circulating biomarkers of oxidative stress. In this study, ferric reducing ability of plasma, thiobarbituric acid-reactive substances, advanced oxidation protein products (AOPPs), and advanced glycation end-products were measured in the serum of CCHS patients to investigate the relationship between oxidative stress and CCHS and the significance of this balance in CCHS. Here, AOPPs were found to be the most relevant serum biomarker to monitor oxidative stress in CCHS patients. According to this communication, CCHS patients may suffer from other chronic pathophysiological processes because of the persistent levels of AOPPs.

Genetically modified animal models of hereditary diseases for testing of gene-directed therapy

Disease-causing genes have been identified for many severe muscular and neurological genetic disorders. Advances in the gene therapy field offer promising solutions for drug development to treat these life-threatening conditions. Depend­ing on how the mutation affects the function of the gene product, different gene therapy approaches may be beneficial. Gene replacement therapy is appropriate for diseases caused by mutations that result in the deficiency of the functional protein. Gene suppression strategy is suggested for disorders caused by the toxic product of the mutant gene. Splicing modulators, genome editing, and base editing techniques can be applied to disorders with different types of underlying mutations. Testing potential drugs in animal models of human diseases is an indispensable step of development. Given the specific gene therapy approach, appropriate animal models can be generated using a variety of technologies ranging from transgenesis to precise genome editing. In this review, we discuss technologies used to generate small and large animal models of the most common muscular and neurological genetic disorders. We specifically focus on animal mod­els that were used to test gene therapies based on adeno-associated vectors and antisense nucleotides.

The Hold me Tight Program for Couples Facing Huntington's Disease.

A positive predictive genetic test for Huntington's disease (HD) can be a life-changing event for both carriers and their partners, leading to lower wellbeing and increasing the risk for separation and divorce. The 'Hold me Tight' program (HmT), based on emotionally focused couples' therapy, aims at strengthening the couple bond by targeting attachment needs. This study investigates whether the HmT program helps couples strengthen their relationship, as an investment in a future where the disease will affect life in many ways. In a multiple baseline design using three baselines of varying length, 15 couples of presymptomatic HD-carriers and their partners were included. In three consecutive groups, couples underwent the intervention (an adapted version of the 8-session HmT program) in four weekly sessions and completed self-report questionnaires throughout the study period of 19 weeks (17 measurements). Attachment style was assessed at baseline, resilience at baseline and at the end of the follow-up, while relationship satisfaction and wellbeing were measured weekly. A multi-level model was applied to the data. Over the course of the study, wellbeing and relationship satisfaction significantly improved; resilience, however, did not. Furthermore, all three outcome measures were moderated by attachment style, with more securely attached individuals showing better outcomes. HmT improved wellbeing and relationship satisfaction of couples facing HD. Due to these improvements and high patient acceptability rates, this program could become a standardized procedure in HD care. The program could be adapted for other populations, e.g., couples facing other genetic neurological disorders.

Adeno-Associated Viruses for Modeling Neurological Diseases in Animals: Achievements and Prospects.

Adeno-associated virus (AAV) vectors have become an attractive tool for efficient gene transfer into animal tissues. Extensively studied as the vehicles for therapeutic constructs in gene therapy, AAVs are also applied for creating animal models of human genetic disorders. Neurological disorders are challenging to model in laboratory animals by transgenesis or genome editing, at least partially due to the embryonic lethality and the timing of the disease onset. Therefore, gene transfer with AAV vectors provides a more flexible option for simulating genetic neurological disorders. Indeed, the design of the AAV expression construct allows the reproduction of various disease-causing mutations, and also drives neuron-specific expression. The natural and newly created AAV serotypes combined with various delivery routes enable differentially targeting neuronal cell types and brain areas in vivo. Moreover, the same viral vector can be used to reproduce the main features of the disorder in mice, rats, and large laboratory animals such as non-human primates. The current review demonstrates the general principles for the development and use of AAVs in modeling neurological diseases. The latest achievements in AAV-mediated modeling of the common (e.g., Alzheimer’s disease, Parkinson’s disease, ataxias, etc.) and ultra-rare disorders affecting the central nervous system are described. The use of AAVs to create multiple animal models of neurological disorders opens opportunities for studying their mechanisms, understanding the main pathological features, and testing therapeutic approaches.

Brain somatic mutations as RNA therapeutic targets in neurological disorders.

Research into the genetic etiology of a neurological disorder can provide directions for genetic diagnosis and targeted therapy. In the past, germline mutations, which are transmitted from parents or newly arise from parental germ cells, were considered as major genetic causes of neurological disorders. However, recent evidence has shown that somatic mutations in the brain, which can arise from neural stem cells during development or over aging, account for a significant number of brain disorders, ranging from neurodevelopmental, neurodegenerative, and neuropsychiatric to neoplastic disease. Moreover, the identification of disease-causing somatic mutations or mutated genes has provided new insights into molecular pathogenesis and unveiled potential therapeutic targets for treating neurological disorders that have few, or no, therapeutic options. RNA therapeutics, including antisense oligonucleotide (ASO) and small interfering RNA (siRNA), are emerging as promising therapeutic tools for treating genetic neurological disorders. As the number of approved and investigational ASO and siRNA drugs for neurological disorders associated with germline mutations increases, they may also prove to be attractive modalities for treating neurologic disorders resulting from somatic mutations. In this perspective, we highlight several neurological diseases caused by brain somatic mutations and discuss the potential role of RNA therapeutics in these conditions.

Effects of Robotic Interactive Gait Training Combined with Virtual Reality and Augmented Reality on Balance, Gross Motor Function, Gait Kinetic, and Kinematic Characteristics in Angelman Syndrome: A Case Report

Angelman syndrome (AS) is a genetic neurological disorder resulting in cognitive and neuromuscular impairments, such as lack of safety awareness and attention, as well as lack of balance and locomotor control. The robotic interactive gait training (RIGT) system is designed to provide accurate proprioceptive, kinematic, and kinetic feedback, and facilitate virtual reality and augmented reality (VR-AR) interactive exercises during gait training. In the present case report, we examined the effect of an innovative hip-knee-ankle interlimb-coordinated RIGT system. We utilized this therapeutic modality in a participant with Angelman syndrome (AS). Gross motor function measures, risk of fall, and gait-related kinetic (force), and kinematic (joint angle) biomechanical characteristics were assessed before and after 20 sessions of RIGT with VR-AR. We found RIGT with VR-AT improved gait ability, as shown by Performance-Oriented Mobility Assessment score, gross motor function by Gross Motor Function Measure score, balance by Pediatric Balance Scale score, knee and hip joint kinetics, and kinematics during gait. Our clinical and biomechanical evidence provide important clinical insights to improve the effectiveness of current neurorehabilitation approaches for treating patients with AS in balance and locomotor control and reduce the risk of falling.

Whole genome sequencing for the diagnosis of neurological repeat expansion disorders in the UK: a retrospective diagnostic accuracy and prospective clinical validation study

SummaryBackgroundRepeat expansion disorders affect about 1 in 3000 individuals and are clinically heterogeneous diseases caused by expansions of short tandem DNA repeats. Genetic testing is often locus-specific, resulting in underdiagnosis of people who have atypical clinical presentations, especially in paediatric patients without a previous positive family history. Whole genome sequencing is increasingly used as a first-line test for other rare genetic disorders, and we aimed to assess its performance in the diagnosis of patients with neurological repeat expansion disorders.MethodsWe retrospectively assessed the diagnostic accuracy of whole genome sequencing to detect the most common repeat expansion loci associated with neurological outcomes (AR, ATN1, ATXN1, ATXN2, ATXN3, ATXN7, C9orf72, CACNA1A, DMPK, FMR1, FXN, HTT, and TBP) using samples obtained within the National Health Service in England from patients who were suspected of having neurological disorders; previous PCR test results were used as the reference standard. The clinical accuracy of whole genome sequencing to detect repeat expansions was prospectively examined in previously genetically tested and undiagnosed patients recruited in 2013–17 to the 100 000 Genomes Project in the UK, who were suspected of having a genetic neurological disorder (familial or early-onset forms of ataxia, neuropathy, spastic paraplegia, dementia, motor neuron disease, parkinsonian movement disorders, intellectual disability, or neuromuscular disorders). If a repeat expansion call was made using whole genome sequencing, PCR was used to confirm the result.FindingsThe diagnostic accuracy of whole genome sequencing to detect repeat expansions was evaluated against 793 PCR tests previously performed within the NHS from 404 patients. Whole genome sequencing correctly classified 215 of 221 expanded alleles and 1316 of 1321 non-expanded alleles, showing 97·3% sensitivity (95% CI 94·2–99·0) and 99·6% specificity (99·1–99·9) across the 13 disease-associated loci when compared with PCR test results. In samples from 11 631 patients in the 100 000 Genomes Project, whole genome sequencing identified 81 repeat expansions, which were also tested by PCR: 68 were confirmed as repeat expansions in the full pathogenic range, 11 were non-pathogenic intermediate expansions or premutations, and two were non-expanded repeats (16% false discovery rate).InterpretationIn our study, whole genome sequencing for the detection of repeat expansions showed high sensitivity and specificity, and it led to identification of neurological repeat expansion disorders in previously undiagnosed patients. These findings support implementation of whole genome sequencing in clinical laboratories for diagnosis of patients who have a neurological presentation consistent with a repeat expansion disorder.FundingMedical Research Council, Department of Health and Social Care, National Health Service England, National Institute for Health Research, and Illumina.

POSB96 Economic Model for a Gene Therapy in an Ultra-Rare Disease: Expert Validation of Approach and Assumptions

A gene therapy has been developed to treat aromatic L-amino acid decarboxylase (AADC) deficiency, a rare genetic neurological disorder. An economic model to support Health Technology Assessments (HTAs) for this therapy requires the utilization of proxy data and various assumptions to overcome the challenges in paucity of data, such as natural history. This research aimed to validate the modelling assumptions and approach with health economics and outcomes research (HEOR) experts, following clinical validation.

De novo pathogenic variant in SETX causes a rapidly progressive neurodegenerative disorder of early childhood-onset with severe axonal polyneuropathy

Pathogenic variants in SETX cause two distinct neurological diseases, a loss-of-function recessive disorder, ataxia with oculomotor apraxia type 2 (AOA2), and a dominant gain-of-function motor neuron disorder, amyotrophic lateral sclerosis type 4 (ALS4). We identified two unrelated patients with the same de novo c.23C > T (p.Thr8Met) variant in SETX presenting with an early-onset, severe polyneuropathy. As rare private gene variation is often difficult to link to genetic neurological disease by DNA sequence alone, we used transcriptional network analysis to functionally validate these patients with severe de novo SETX-related neurodegenerative disorder. Weighted gene co-expression network analysis (WGCNA) was used to identify disease-associated modules from two different ALS4 mouse models and compared to confirmed ALS4 patient data to derive an ALS4-specific transcriptional signature. WGCNA of whole blood RNA-sequencing data from a patient with the p.Thr8Met SETX variant was compared to ALS4 and control patients to determine if this signature could be used to identify affected patients. WGCNA identified overlapping disease-associated modules in ALS4 mouse model data and ALS4 patient data. Mouse ALS4 disease-associated modules were not associated with AOA2 disease modules, confirming distinct disease-specific signatures. The expression profile of a patient carrying the c.23C > T (p.Thr8Met) variant was significantly associated with the human and mouse ALS4 signature, confirming the relationship between this SETX variant and disease. The similar clinical presentations of the two unrelated patients with the same de novo p.Thr8Met variant and the functional data provide strong evidence that the p.Thr8Met variant is pathogenic. The distinct phenotype expands the clinical spectrum of SETX-related disorders.

Neuronal excitatory-to-inhibitory balance is altered in cerebral organoid models of genetic neurological diseases

The neuro-physiological properties of individuals with genetic pre-disposition to neurological disorders are largely unknown. Here we aimed to explore these properties using cerebral organoids (COs) derived from fibroblasts of individuals with confirmed genetic mutations including PRNPE200K, trisomy 21 (T21), and LRRK2G2019S, which are associated with Creutzfeldt Jakob disease, Down Syndrome, and Parkinson’s disease. We utilized no known disease/healthy COs (HC) as normal function controls. At 3–4 and 6–10 months post-differentiation, COs with mutations showed no evidence of disease-related pathology. Electrophysiology assessment showed that all COs exhibited mature neuronal firing at 6–10 months old. At this age, we observed significant changes in the electrophysiology of the COs with disease-associated mutations (dCOs) as compared with the HC, including reduced neuronal network communication, slowing neuronal oscillations, and increased coupling of delta and theta phases to the amplitudes of gamma oscillations. Such changes were linked with the detection of hypersynchronous events like spike-and-wave discharges. These dysfunctions were associated with altered production and release of neurotransmitters, compromised activity of excitatory ionotropic receptors including receptors of kainate, AMPA, and NMDA, and changed levels and function of excitatory glutamatergic synapses and inhibitory GABAergic synapses. Neuronal properties that modulate GABAergic inhibition including the activity of Na–K-Cl cotransport 1 (NKCC1) in Cl− homeostasis and the levels of synaptic and extra-synaptic localization of GABA receptors (GABARs) were altered in the T21 COs only. The neurosteroid allopregnanolone, a positive modulator of GABARs, was downregulated in all the dCOs. Treatment with this neurosteroid significantly improved the neuronal communication in the dCOs, possibly through improving the GABAergic inhibition. Overall, without the manifestation of any disease-related pathology, the genetic mutations PRNPE200K, T21, and LRRK2G2019S significantly altered the neuronal network communication in dCOs by disrupting the excitatory-to-inhibitory balance.

Adult-onset vanishing white matter disease with psychiatric manifestation: A case report

Leukodystrophies are genetic neurological disorders characterized by involvement of the white matter of the CNS that may occur at all age. The ovarioleukodystrophies comprise a group of rare leukodystrophies associated with primary or premature ovarian failure.

Down regulation of the expression of mitochondrial phosphopantetheinyl-proteins in pantothenate kinase-associated neurodegeneration: pathophysiological consequences and therapeutic perspectives

BackgroundNeurodegeneration with brain iron accumulation (NBIA) is a group of genetic neurological disorders frequently associated with iron accumulation in the basal nuclei of the brain characterized by progressive spasticity, dystonia, muscle rigidity, neuropsychiatric symptoms, and retinal degeneration or optic nerve atrophy. Pantothenate kinase-associated neurodegeneration (PKAN) is the most widespread NBIA disorder. It is caused by mutations in the gene of pantothenate kinase 2 (PANK2) which catalyzes the first reaction of coenzyme A (CoA) biosynthesis. Thus, altered PANK2 activity is expected to induce CoA deficiency as well as low levels of essential metabolic intermediates such as 4′-phosphopantetheine which is a necessary cofactor for critical proteins involved in cytosolic and mitochondrial pathways such as fatty acid biosynthesis, mitochondrial respiratory complex I assembly and lysine and tetrahydrofolate metabolism, among other metabolic processes.MethodsIn this manuscript, we examined the effect of PANK2 mutations on the expression levels of proteins with phosphopantetheine cofactors in fibroblast derived from PKAN patients. These proteins include cytosolic acyl carrier protein (ACP), which is integrated within the multifunctional polypeptide chain of the fatty acid synthase involved in cytosolic fatty acid biosynthesis type I (FASI); mitochondrial ACP (mtACP) associated with mitocondrial fatty acid biosynthesis type II (FASII); mitochondrial alpha-aminoadipic semialdehyde synthase (AASS); and 10-formyltetrahydrofolate dehydrogenases (cytosolic, ALD1L1, and mitochondrial, ALD1L2).ResultsIn PKAN fibroblasts the expression levels of cytosolic FAS and ALD1L1 were not affected while the expression levels of mtACP, AASS and ALD1L2 were markedly reduced, suggesting that 4′-phosphopantetheinylation of mitochondrial but no cytosolic proteins were markedly affected in PKAN patients. Furthermore, the correction of PANK2 expression levels by treatment with pantothenate in selected mutations with residual enzyme content was able to correct the expression levels of mitochondrial phosphopantetheinyl-proteins and restore the affected pathways. The positive effects of pantothenate in particular mutations were also corroborated in induced neurons obtained by direct reprograming of mutant PANK2 fibroblasts.ConclusionsOur results suggest that the expression levels of mitochondrial phosphopantetheinyl-proteins are severely reduced in PKAN cells and that in selected mutations pantothenate increases the expression levels of both PANK2 and mitochondrial phosphopantetheinyl-proteins associated with remarkable improvement of cell pathophysiology.

Novel Concepts for the Role of Chloride Cotransporters in Refractory Seizures.

Epilepsy is associated with a multitude of acquired or genetic neurological disorders characterized by a predisposition to spontaneous recurrent seizures. An estimated 15 million patients worldwide have ongoing seizures despite optimal management and are classified as having refractory epilepsy. Early-life seizures like those caused by perinatal hypoxic ischemic encephalopathy (HIE) remain a clinical challenge because although transient, they are difficult to treat and associated with poor neurological outcomes. Pediatric epilepsy syndromes are consistently associated with intellectual disability and neurocognitive comorbidities. HIE and arterial ischemic stroke are the most common causes of seizures in term neonates and account for 7.5-20% of neonatal seizures. Standard first-line treatments such as phenobarbital (PB) and phenytoin fail to curb seizures in ~50% of neonates. In the long-term, HIE can result in hippocampal sclerosis and temporal lobe epilepsy (TLE), which is the most common adult epilepsy, ~30% of which is associated with refractory seizures. For patients with refractory TLE seizures, a viable option is the surgical resection of the epileptic foci. Novel insights gained from investigating the developmental role of Cl- cotransporter function have helped to elucidate some of the mechanisms underlying the emergence of refractory seizures in both HIE and TLE. KCC2 as the chief Cl- extruder in neurons is critical for enabling strong hyperpolarizing synaptic inhibition in the brain and has been implicated in the pathophysiology underlying both conditions. More recently, KCC2 function has become a novel therapeutic target to combat refractory seizures.

Primary Small Bowel Neurofibroma Induced Intussusception Complicated with Small Bowel Obstruction and Perforation: A Case Report

Neurofibromatosis (NF) is a genetic neurological disorder which can lead to abnormal tumour suppression. Neurofibromatosis associated neurological tumour is usually benign in nature, only occasionally can become malignant. Gastrointestinal involvement is reported to be infrequent with only up to 25% of patients with neurofibromatosis showing involvement. Solitary gastrointestinal neurofibroma is very rare, with most cases involving the stomach or small bowel. We report here a case of solitary small intestinal neurofibroma with no other associated systemic signs, causing intussusception and intestinal obstruction.

Diagnostic yield and treatment impact of whole-genome sequencing in paediatric neurological disorders.

To investigate the diagnostic yield and treatment impact of whole-genome sequencing (WGS) in patients with paediatric neurological disorders. From January 2016 to December 2019, paediatric patients who had suspected genetic neurological disorders were assessed using WGS. The phenotypes of eligible patients were divided into four groups: patients with neurodevelopmental disorders; patients with epilepsy; patients with neuromuscular disorders; and patients with movement disorders. A total of 214 consecutive patients (128 males, 86 females) underwent WGS. The mean (SD) age of disease onset was 13.8 (27.6) months (range 1d-15y 5mo). The mean (SD) age at which WGS was performed was 71.7 (58.9) months (range 8d-18y). A molecular diagnosis was reported in 43.9% of patients. The highest diagnostic rate was achieved in 62.5% of patients with neuromuscular disorders, 47.5% of patients with epilepsy, 41.1% of patients with neurodevelopment disorders, and 15.4% of patients with movement disorders. All 94 patients with a WGS diagnosis were given access to genetic counselling and 23.4% of patients had immediate changes in treatment strategies after undergoing WGS. WGS allows paediatric neurologists to integrate genomic data into their diagnosis and adjust management strategies for a range of clinical and genetically heterogeneous disease entities to improve the clinical outcomes of patients. In our cohort, the diagnosis of a significant proportion of patients was reached through WGS (43.9%). Clinicians could use these results to directly guide the management of their patients and improve their clinical outcomes (23.4%). What this paper adds For selected children in our cohort, the diagnostic yield of whole-genome sequencing (WGS) was 43.9%. WGS can be used to expand our knowledge of phenotype-genotype variations.

Bilateral hypertrophic olivary degeneration in genetic neurological disorders

Hypertrophic olivary degeneration (HOD) is a rare variant of transsynaptic degeneration in the inferior olivary nuclei due to a lesion within the dentato-rubro- olivary pathway, also known as the Guillain–Mollaret triangle. Bilateral HOD can be identified on MRI in patients with not only acquired but also genetic neurological disorders. The article describes patients with both common and rare genetic causes of the bilateral HOD. The pathophysiology of HOD is also briefly reviewed.