Revisiting Exome Data Identified Missed Splice Site Variant of the Asparagine Synthetase ( ASNS ) Gene.

Next-generation sequencing, such as whole-exome sequencing (WES), is increasingly used in the study of Mendelian disorders, yet many are reported as "negative." Inappropriate variant annotation and filtering steps are reasons for missing the molecular diagnosis. Noncoding variants, including splicing mutations, are examples of variants that can be overlooked. Herein, we report a family of four affected newborns, and all presented with severe congenital microcephaly. Initial research WES analysis identified a damaging homozygous variant in NME1 gene as a possible cause of primary microcephaly phenotype in these patients. However, reanalysis of the exome data uncovered a biallelic splice site variant in asparagine synthetase gene which seems to be the possible cause of the phenotype in these patients. This study highlights the importance of revisiting the exome data and the issue of "negative" exome and the afterward approaches to identify and prove new candidate genes.

Biallelic variants in the synaptic vesicle glycoprotein 2 A are associated with epileptic encephalopathy.

Synaptic Vesicle Glycoprotein 2 A (SV2A) is a membrane protein of synaptic vesicles and the binding site of antiepileptic drug levetiracetam. Biallelic Arg383Gln is reported in a family with intractable epilepsy earlier. Here, we report on the second family with early onset drug resistant epilepsy. We identified homozygous Arg289Ter variant by exome sequencing that segregated with the phenotype in the family. The affected children in these two families are normal at birth and developed recurrent seizures beginning in the second month of life and developed secondary failure of growth and development. Knock out mice models earlier had replicated the human phenotype observed in these two families. These findings support that biallelic loss of function variants in SV2A result in early onset intractable epilepsy in humans.

Expanding the clinical spectrum of cytosolic phosphoenolpyruvate carboxykinase deficiency: novel PCK1 variants in four Arabian Gulf families.

BACKGROUND: In metabolic stress, the cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) enzyme is involved in energy production through the gluconeogenesis pathway. PEPCK-C deficiency is a rare childhood-onset autosomal recessive metabolic disease caused by PCK1 genetic defects. Previous studies showed a broad clinical spectrum ranging from asymptomatic to recurrent hypoglycemia with/without lactic acidosis, encephalopathy, seizures, and liver failure. RESULTS: In this article, we discuss the occurrence of PEPCK-C deficiency in four families from the United Arab Emirates and Oman. All patients presented with unexplained hypoglycemia as a common feature. Two out of the seven patients presented with episodes of encephalopathy that resulted in seizures and neuroregression leading to global developmental delay and one patient had a neonatal presentation. Observed biochemical abnormalities include elevated lactate, transaminases, and tricarboxylic acid cycle metabolites in most patients. Elevated creatine kinase was documented in two patients. Whole exome sequencing revealed two novel (c.574T > C, and c.1268 C > T) and a previously reported splice site (c.961 + 1G > A) PCK1 variant in the affected families. CONCLUSION: Patients become vulnerable during intercurrent illness; thus, prevention and prompt reversal of a catabolic state are crucial to avoid irreversible brain damage. This report will help to expand the clinical understanding of this rare disease and recommends screening for PEPCK-C deficiency in unexplained hypoglycemia.

Delayed myelopathy in a child following organic phosphate poisoning.

We report a rare manifestation of delayed organophosphate (OP) poisoning in a male patient in his early childhood. After initially presenting with a cholinergic crisis after OP exposure, the patient returned 3 weeks later with paraparesis and difficulty with bladder control. The results of the MRI of the spine and brain as well as the nerve conduction studies were normal. Myelopathy induced by OP poisoning should be considered in any patient with a history of OP exposure and a presentation of paraparesis. At most recent follow-up, the patient had full bladder control and could walk without assistance. However, he demonstrated circumduction while walking with upper motor neuron signs. Furthermore, he had mild Achilles tendon contractures on both sides. To enable early detection, neurologists and paediatricians should be aware of this uncommon complication of OP poisoning which may influence neurological outcome.

Autosomal Recessive NOTCH3-Related Leukodystrophy in Two Siblings and Review of the Literature.

BACKGROUND: NOTCH3, a large type I transmembrane receptor expressed on arterial smooth muscle cells and capillary pericytes, features a diverse extracellular domain with 34 epidermal growth factor-like repeats. It exhibits distinct phenotypes due to variant zygosity and type; missense mutations cause CADASIL with cerebral vasculopathy, while null mutations lead to severe congenital manifestations. METHODS: This report describes two cases with homozygous loss- of- function variants in NOTCH3 along with their clinical manifestations. RESULTS: These patients presented with a severe congenital phenotype, including eye misalignment, visual impairment, epilepsy, global developmental delay, and subsequent development of pyramidal signs. Biallelic nonsense variants were discovered in both the cases (NM_000435.3:c.2203 C > T (p. [Arg735Ter]). Livedo reticularis was not reported in our cases, although it was present in previously reported patients. Autosomal recessive NOTCH3-related leukodystrophy is usually caused by biallelic null mutations in NOTCH3. CONCLUSIONS: The phenotype of biallelic null variants is associated with a more severe phenotype than the dominantly inherited form of the disease.

Guillain-Barré Syndrome Associated with SARS-CoV-2 in Two Pediatric Patients.

Guillain-Barré syndrome (GBS) is a recognised complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report two children with GBS associated with SARS-CoV-2 who presented to a tertiary centre in Muscat, Oman in 2021: The first patient was a three-month-old female infant who presented with bradypnea, encephalopathy, and generalised weakness that required mechanical ventilation. Polymerase chain reaction (PCR) testing of the nasopharyngeal swabs (NPS) was positive for SARS-CoV-2. She had axonal variant GBS based on a nerve conduction study, cerebrospinal fluid analysis, and neuroimaging findings. The second patient was a six-year-old girl with fever, vomiting, and diarrhea followed by ascending weakness who presented with quadriplegia and facial weakness. Subsequently, she developed respiratory muscle weakness and required mechanical ventilation. PCR testing of NPS was negative for SARS-Cov-2, however IgG serology analysis was positive. The clinical course of these two patients was rapidly progressive and both of them required mechanical ventilation. The patient with axonal variant GBS made an incomplete recovery.

Tuberous Sclerosis Complex with Renal Stones and Distal Renal Tubular Acidosis: Case Report and Literature Review.

Distal renal tubular acidosis (RTA) is a common cause of renal stones and nephrocalcinosis in children. Distal RTA can be either acquired or congenital because of a genetic defect. Tuberous sclerosis complex is an autosomal dominant inherited neurocutaneous syndrome with variable renal involvement. We describe a case of a six-year-old boy with tuberous sclerosis complex who developed distal RTA and renal stones.

Pediatric Migraines: A Comprehensive Review and Perspectives on Diagnosis and Treatment.

Pediatric migraine (PM) is one of the most prevalent neurological disorders in children. It has numerous variants and the sufferers often present to emergency departments with a wide variety of signs and symptoms that make diagnosis difficult. The trend in diagnosing and managing PM cases remain suboptimal despite the comprehensive diagnostic criteria and various therapeutic options. In this review, we discuss PM, provide an approach to the diagnosis, and describe the various available management options. However, the diagnosis of migraine is based on history and physical examination; no specific diagnostic test is available. The main management aspects are acute pain relief, prevention, and identifying triggering factors.

Case report: Cyclosporine A-induced extrapyramidal syndrome following hematopoietic stem cell transplantation.

Introduction: Cyclosporine A-associated neurotoxicity has been reported in up to 40% of patients and its wide range of neurological adverse effects have been reported, ranging from mild tremors to fatal leukoencephalopathy. Extrapyramidal (EP) neurotoxicity is a rare manifestation of cyclosporine. Cyclosporine-induced extrapyramidal syndrome remains a rare adverse reaction. Design/methods: A database search was performed for studies in patients from all age groups. We found a total of 10 articles reporting EP as an adverse effect of cyclosporine A. A total of 16 patients were found, and a thorough review of these patients was performed. A comparison of patients was performed to highlight common clinical presentations, investigations during the symptomatic phase, and prognosis. In addition, we describe an 8-year-old boy who developed cyclosporine-related extrapyramidal signs on day 60 post-hematopoietic stem cell transplantation for beta-thalassemia. Conclusion: Cyclosporine A can induce neurotoxicity resulting in diverse symptoms. Signs of EP are rare manifestations of cyclosporine neurotoxicity and should be considered when evaluating post-transplant recipients of cyclosporine when they are present with any EP symptoms. Discontinuation of cyclosporine results in good recovery in most patients.

Assessment of quality of life in children with epilepsy in Oman.

PURPOSE: The study aims to describe the quality of life (QoL) in Omani children with epilepsy at Sultan Qaboos University Hospital, Oman. METHODS: One hundred and one Omani children, with an age range from 5 to 18 years, diagnosed with epilepsy were enrolled in the study over 3 months. Descriptive epidemiology was used to characterize QoL in these children. QoL was measured using the PedsQL (4.0) questionnaire, a 23-item child and parent report questionnaire. Analysis of variance (ANOVA) was used to compare mean QoL scores, and agreement between the QoL reports of children and parents was evaluated using Spearman's rho; while, Multivariate analysis of variance (MANOVA) was performed to determine differences in subscale ratings. RESULTS: Factors affecting QoL included family status, income level, social security coverage, type of treatment, seizure frequency, age of onset, and seizure-free duration in years. Children between 5 and 7 years and females, in general, were most affected, as reflected by the overall QoL subscale. Consistency between the children's self-reports and parent proxy reports on the PedsQL™ was moderate to low. CONCLUSION: Omani children with epilepsy have poor QoL, and their psychosocial function is severely affected. Therefore, QoL should be an important outcome measure in managing children with epilepsy rather than just seizure control.

N-Methyl-D-Aspartate Receptor Encephalitis, Post Herpes Encephalitis in Two Pediatric Cases.

Commonly, herpes simplex virus (HSV) causes infectious encephalitis among children. A neurological relapse after primary HSV encephalitis in the weeks or months after presentation is well recognized. Relapsing symptoms of post-HSV encephalitis can present either as a true relapse or an immune-mediated disorder. A relationship is predicted between immune-mediated disorder and N-methyl-D-aspartate receptor (NMDAR) antibodies. This study presents two cases of patients suffering from anti-NMDAR encephalitis that appeared after treatment for proven HSV encephalitis. The first patient was treated immediately after the presentation as autoimmune encephalitis and had an excellent outcome. The second patient had delayed initiation of treatment and suffered from intractable epilepsy and severe global developmental delay. An important role is played by recognizing anti-NMDAR encephalitis symptoms and its variable presentation for timely diagnosis and quick initiation of treatment for anti-NMDAR encephalitis, thus, improving the outcome for those patients.

The diagnostic yield, candidate genes, and pitfalls for a genetic study of intellectual disability in 118 middle eastern families.

Global Developmental Delay/Intellectual disability (ID) is the term used to describe various disorders caused by abnormal brain development and characterized by impairments in cognition, communication, behavior, or motor skills. In the past few years, whole-exome sequencing (WES) has been proven to be a powerful, robust, and scalable approach for candidate gene discoveries in consanguineous populations. In this study, we recruited 215 patients affected with ID from 118 Middle Eastern families. Whole-exome sequencing was completed for 188 individuals. The average age at which WES was completed was 8.5 years. Pathogenic or likely pathogenic variants were detected in 32/118 families (27%). Variants of uncertain significance were seen in 33/118 families (28%). The candidate genes with a possible association with ID were detected in 32/118 (27%) with a total number of 64 affected individuals. These genes are novel, were previously reported in a single family, or cause strikingly different phenotypes with a different mode of inheritance. These genes included: AATK, AP1G2, CAMSAP1, CCDC9B, CNTROB, DNAH14, DNAJB4, DRG1, DTNBP1, EDRF1, EEF1D, EXOC8, EXOSC4, FARSB, FBXO22, FILIP1, INPP4A, P2RX7, PRDM13, PTRHD1, SCN10A, SCYL2, SMG8, SUPV3L1, TACC2, THUMPD1, XPR1, ZFYVE28. During the 5 years of the study and through gene matching databases, several of these genes have now been confirmed as causative of ID. In conclusion, understanding the causes of ID will help understand biological mechanisms, provide precise counseling for affected families, and aid in primary prevention.

The Parental and Children Report of the Prevalence of Depressive Symptoms in Children and Adolescents Amid the COVID-19 Pandemic: A Cross-Sectional Study From Oman.

Objective: Studies from the past decades have shown that mood disorders are common during childhood and adolescence. This study aimed to estimate the point prevalence of depression in Omani children and adolescents during social distancing and lockdown and identify the risk factors for developing depressive symptoms during the COVID-19 pandemic. Methods: This is an analytical cross-sectional study conducted in May 2020, in which all young Omani people attending a mainstream school aged 8-18 years old were eligible to participate. Parents were asked to complete the online survey, which consisted of the parent version of the Mood and Feelings Questionnaire (MFQ-Parent). In addition, the option of a self-reported version (MFQ-Self) was provided in cases where children preferred to fill out the survey themselves. Logistic regression was used to identify the contributing socio-demographic variables associated with depressive symptoms. Results: A total of 445 participants completed the MFQ, out of which 72.1% were parents, and 27.9% were children, adolescents and young people. 13.9% of children and adolescents exhibited depressive symptoms during the COVID-19 pandemic in Oman. The presence of depressive symptoms was associated with increased food intake (OR 1.81, 95% CI 1.00-3.29, p-value <0.05), longer use of smartphones (OR 2.72, 95% CI 1.56-4.73, p-value <0.001), whereas additional entertainment activities during lockdown were protective against depression (OR 0.35 95% CI 0.19-0.64, p-value <0.001). Conclusion: This study from Oman concurs with recent reports of depression being common during the COVID-19 pandemic. Concerted efforts are needed to mitigate this trend and identify high-risk groups during the lockdown period.

Childhood Absence Epilepsy Associated With Concomitant Centrotemporal Spikes.

Objectives The coexistence of generalized epileptiform discharges of 3Hz spike-and-wave complexes, which are the hallmark of childhood absence epilepsy (CAE), and centrotemporal spikes, which are characteristic of benign epilepsy with centrotemporal spikes (BECTs) in the same or subsequent EEGs appears to be very rare. Only a few published reports have shown a possible concomitance of CAE and BECTs electrographic changes. The study aimed to analyze electrographic and clinical features of patients with CAE who had concomitant or subsequent EEG features of BECTs. Method During a five-year analysis period (2014-2018), 277 children with BECTs and 93 children with CAE were diagnosed and treated at the pediatric neurology unit of Sultan Qaboos University Hospital (SQUH) in Muscat, Oman. Nine patients were identified to have overlapping EEG findings of both epileptic syndromes. We then analyzed the nine children's clinical features, outcomes, and EEG findings in detail. Results The clinical onset of all our patients aged 5-14 years (six boys, three girls) was characterized by the absence of seizures, either typical (seven children) or atypical (two children). Six out of nine patients presented with concomitant electrographic features of both syndromes, whereas three patients experienced the EEG pattern of two syndromes at different times. All nine children were treated with valproate as the first-line medication, with reasonable seizure control. However, three patients required a second add-on medication. Despite good seizure control, six of our patients had poor school performance and five children had comorbid conditions such as ADHD and learning disability. Conclusion The coexistence of CAE and BECTS is described in the literature albeit rare. This overlap is mostly in electrographic features with or without the clinical features seen in both syndromes.

TMEM63C mutations cause mitochondrial morphology defects and underlie hereditary spastic paraplegia.

The hereditary spastic paraplegias (HSP) are among the most genetically diverse of all Mendelian disorders. They comprise a large group of neurodegenerative diseases that may be divided into 'pure HSP' in forms of the disease primarily entailing progressive lower-limb weakness and spasticity, and 'complex HSP' when these features are accompanied by other neurological (or non-neurological) clinical signs. Here, we identified biallelic variants in the transmembrane protein 63C (TMEM63C) gene, encoding a predicted osmosensitive calcium-permeable cation channel, in individuals with hereditary spastic paraplegias associated with mild intellectual disability in some, but not all cases. Biochemical and microscopy analyses revealed that TMEM63C is an endoplasmic reticulum-localized protein, which is particularly enriched at mitochondria-endoplasmic reticulum contact sites. Functional in cellula studies indicate a role for TMEM63C in regulating both endoplasmic reticulum and mitochondrial morphologies. Together, these findings identify autosomal recessive TMEM63C variants as a cause of pure and complex HSP and add to the growing evidence of a fundamental pathomolecular role of perturbed mitochondrial-endoplasmic reticulum dynamics in motor neurone degenerative diseases.

EEG Pattern in Neonatal Maple Syrup Urine Disease: Description and Clinical Significance.

Maple Syrup Urine Disease (MSUD) is a rare autosomal recessive disorder characterized by deficiency of branched-chain keto acid dehydrogenase complex, which is required to metabolize the three branched chain amino acids (BCAAs), leucine, isoleucine and valine. This metabolic dysfunction results in progressive encephalopathy manifesting with lethargy, vomiting, posturing and abnormal movements during the neonatal period in the classic form of the disease. If untreated, progressive brain damage causes coma, seizures and death usually within a few weeks. EEG is an essential investigation in a neonate with progressive encephalopathy and seizures. EEG abnormalities in neonatal encephalopathies due to inborn error of metabolism (IEM) are widely variable depending on the severity. Central comb-like rhythm is an EEG marker of neonatal MSUD in appropriate clinical context. This pattern should not be mistaken for epileptic abnormalities, sleep spindles or other similar nonspecific activities. We describe a patient with classic MSUD who presented with an EEG pattern of comb-like rhythm. Background abnormalities and epileptic discharges are common along comb-like rhythm in MSUD patients. EEG technologists and interpreters should be able to identify this pattern to support the early diagnosis and treatment of MSUD.

Clinico-electrographic characteristics and classification of genetic generalized epilepsy in Oman.

PURPOSE: There is a lack of information on the annual incidence of genetic generalized epilepsy (GGE) in the Arab countries, especially Oman. Ascertaining the true burden of illness has crucial implications for health policies and priorities. We aim to study the clinico-electrographic characteristics, classification, and annual incidence of GGE in Oman. METHOD: Using the cross-sectional data of EEGs obtained from all patients with GGE who presented to Sultan Qaboos University hospital (major referral center for epilepsy in Oman) from January 2007 to June 2014. Analyses were performed using univariate statistics. RESULTS: Approximately 10,423 patients had EEG studies during the study period of which 376 patients (3.6 %) had EEG abnormalities suggestive of GGE. Forty two percent of the 376 GGE patients were male with ages ranging from 3 to 58 years. We were able to classify 273 patients to one of the GGE syndromes. Forty-three percent of 130 patients had a positive family history of epilepsy in their first or second-degree relatives. The generalized tonic-clonic seizure was the most common seizure type observed in 242 patients (64 %; 95 %CI: 59.2 %-68.9 %). Juvenile myoclonic epilepsy was the most common epilepsy syndrome (41 % of the total GGE patients) encountered in our region. A significant female predominance (9.7 % vs 2.5 %; p = 0.016) was observed in juvenile absence epilepsy. Certain interictal focal EEG abnormalities did not exclude a diagnosis of GGE. An average annual GGE incidence of 2.9 % (95 % CI: 2.6 %-3.2 %) was observed during the study period. CONCLUSION: This hospital-based study is the first of its kind in the Arabian Gulf region, classifying the different subcategories of GGE. Our results indicate that GGE is a common epilepsy subtype in Oman. A prospective population-based epidemiological study is required to estimate the precise frequency of GGE in Oman.