Aicardi-Goutières Syndrome Type 1: A Novel Missense Variant and Review of the Mutational Spectrum.

Objectives: Mutations in the TREX1 gene cause Aicardi-Goutières syndrome (AGS) 1, associated with a spectrum of autoimmune and neurodegenerative manifestations. AGS 1, the most severe neonatal type of AGS, is characterized by abnormal neurologic findings, visual inattention, hepatosplenomegaly, thrombocytopenia, skin rash, restlessness, and fever. Materials & Methods: The present study described two affected siblings from an Iranian family whose phenotypes overlap with intrauterine infections. They had almost similar presentations, including developmental delay, microcephaly, no fix and follow epileptic seizures and the same pattern of brain CT scan involvements. Following clinical and paraclinical assessments, whole-exome sequencing was employed to determine the disease-causing variant, and subsequently, PCR-Sanger sequencing was performed to indicate the segregation pattern of the candidate variant in family members. Results: Genetic analysis revealed a novel homozygous missense variant (c.461A>C; p.D154A) in the TREX1 gene in affected family members. Sanger sequencing of other family members showed the expected zygosities. Conclusion: This study identifies a novel mutation in the TREX1 gene in this family and highlights the efficiency of next-generation sequencing-based techniques for obtaining a definite diagnosis in patients with early-onset encephalopathy.

The full spectrum of MRI findings in 18 patients with Canavan disease: new insights into the areas of selective susceptibility.

INTRODUCTION: Canavan disease (CD) is a rare autosomal recessive neurodegenerative disorder caused by a deficiency of aspartoacylase A, an enzyme that degrades N-acetylaspartate (NAA). The disease is characterized by progressive white matter degeneration, leading to intellectual disability, seizures, and death. This retrospective study aims to describe the full spectrum of magnetic resonance imaging (MRI) findings in a large case series of CD patients. MATERIALS AND METHODS: MRI findings in 18 patients with confirmed CD were investigated, and the full spectrum of brain abnormalities was compared with the existing literature to provide new insights regarding the brain MRI findings in these patients. All the cases were proven based on genetic study or NAA evaluation in urine or brain. RESULTS: Imaging analysis showed involvement of the deep and subcortical white matter as well as the globus pallidus in all cases, with sparing of the putamen, caudate, and claustrum. The study provides updates on the imaging characteristics of CD and validates some underreported findings such as the involvement of the lateral thalamus with sparing of the pulvinar, involvement of the internal capsules and corpus callosum, and cystic formation during disease progression. CONCLUSION: To our knowledge, this is one of the largest case series of patients with CD which includes a detailed description of the brain MRI findings. The study confirmed many of the previously reported MRI findings but also identified abnormalities that were previously rarely or not described. We speculate that areas of ongoing myelination are particularly vulnerable to changes in CD.

GM1 and GM2-Gangliosidosis: Clinical Features, Neuroimaging Findings and Electroencephalography.

Abstract: Gangliosidosis is one of the hereditary metabolic diseases caused by the accumulation of Gangliosid in the central nervous system, leading to severe and progressive neurological deficits. Regarding phenotype, GM1 and GM2-Gangliosidosis are divided into Infantile, Juvenile, and Adult. Materials & Methods: In this study, thirty-seven patients with GM1 and GM2-Gangliosidosis were referred to the neurology department of Mofid Children's Hospital in Tehran, Iran, whose disease was confirmed from September 2019 to December 2021. This study assessed age, sex, and developmental status before the onset of the disease, clinical manifestations, brain imaging, and electroencephalography. Results: 97.20% of patients were the result of family marriage. Approximately 80% of juvenile patients were developmentally normal before the onset of the disease. Developmental delay was more common among infantile GM1-Gangliosidosis than infantile GM2-Gangliosidosis, but in total, more than 50% of GM1&GM2-Gangliosidosis patients had reached their developmental milestone before the onset of the disease. With the onset of disease symptoms, 100% of patients regressed in terms of movement, 97.20% of them mentally, and 75% of them had seizures during the disease. The most common clinical findings were cherry-red spot, Mongolian spot, macrocephaly, organomegaly, hyperacusis, and scoliosis. The most common brain imaging findings included bilateral thalamus involvement, brain atrophy, PVL, and delayed myelination. The most common finding in electroencephalography was background low voltage with abnormal sharp waves. Conclusion: This study concluded that most of the patients are the result of family marriage, and most of the juvenile patients are developmentally normal before the onset of the disease. In addition, more than 50% of infantile patients reach their developmental milestones before the onset of the disease. The most common clinical findings of these patients are seizures, cherry-red spot, macrocephaly, hyperacusis, Mongolian spot, and bilateral involvement of the thalamus.

Identification of novel mutations in TPK1 and SLC19A3 genes in families exhibiting thiamine metabolism dysfunction syndrome.

Background and aims: The occurrence of thiamine metabolism dysfunction syndrome (THMD), a rare autosomal recessive condition, may be linked to various mutations found in the TPK1 and SLC19A3 genes. The disease chiefly manifests through ataxia, muscle hypotonia, abrupt or subacute onset encephalopathy, and a decline in developmental milestones achieved during the early stages of infancy. We present findings from an investigation that involved two individuals from Iran, both of whom experienced seizures along with ataxia and hypotonia. The underlying genetic causes were found with the use of next-generation sequencing (NGS) technology, which has facilitated the detection of causal changes in a variety of genetic disorders. Material and methods: The selection of cases for this study was based on the phenotypic and genetic information that was obtainable from the Center for Comprehensive Genetic Services. The genetic basis for the problems observed among the participants was determined through the application of whole-exome sequencing (WES). Subsequently, sanger sequencing was employed as a means of validating any identified variations suspected to be causative. Results: The first patient exhibited a homozygous mutation in the TPK1 gene, NM_022445.4:c.224 T > A:p.I75 N, resulting in the substitution of isoleucine for asparagine at position 75 (p.I75 N). In our investigation, patient 2 exhibited a homozygous variant, NM_025243.4:c.1385dupA:pY462X, within the SLC19A3 gene. Conclusions: Collectively, when presented with patients showcasing ataxia, encephalopathy, and basal ganglia necrosis, it is essential to account for thiamine deficiency in light of the potential advantages of prompt intervention. At times, it may be feasible to rectify this deficiency through the timely administration of thiamine dosages. Accordingly, based on the results of the current investigation, these variations may be useful for the diagnosis and management of patients with THMD.

Clinical application of next generation sequencing for Mendelian disease diagnosis in the Iranian population.

Next-generation sequencing (NGS) has been proven to be one of the most powerful diagnostic tools for rare Mendelian disorders. Several studies on the clinical application of NGS in unselected cohorts of Middle Eastern patients have reported a high diagnostic yield of up to 48%, correlated with a high level of consanguinity in these populations. We evaluated the diagnostic utility of NGS-based testing across different clinical indications in 1436 patients from Iran, representing the first study of its kind in this highly consanguineous population. A total of 1075 exome sequencing and 361 targeted gene panel sequencing were performed over 8 years at a single clinical genetics laboratory, with the majority of cases tested as proband-only (91.6%). The overall diagnostic rate was 46.7%, ranging from 24% in patients with an abnormality of prenatal development to over 67% in patients with an abnormality of the skin. We identified 660 pathogenic or likely pathogenic variants, including 241 novel variants, associated with over 342 known genetic conditions. The highly consanguineous nature of this cohort led to the diagnosis of autosomal recessive disorders in the majority of patients (79.1%) and allowed us to determine the shared carrier status of couples for suspected recessive phenotypes in their deceased child(ren) when direct testing was not possible. We also highlight the observations of recessive inheritance of genes previously associated only with dominant disorders and provide an expanded genotype-phenotype spectrum for multiple less-characterized genes. We present the largest mutational spectrum of known Mendelian disease, including possible founder variants, throughout the Iranian population, which can serve as a unique resource for clinical genomic studies locally and beyond.

Broadening the phenotype and genotype spectrum of novel mutations in pontocerebellar hypoplasia with a comprehensive molecular literature review.

BACKGROUND: Pontocerebellar hypoplasia is an umbrella term describing a heterogeneous group of prenatal neurodegenerative disorders mostly affecting the pons and cerebellum, with 17 types associated with 25 genes. However, some types of PCH lack sufficient information, which highlights the importance of investigating and introducing more cases to further elucidate the clinical, radiological, and biochemical features of these disorders. The aim of this study is to provide an in-depth review of PCH and to identify disease genes and their inheritance patterns in 12 distinct Iranian families with clinically confirmed PCH. METHODS: Cases included in this study were selected based on their phenotypic and genetic information available at the Center for Comprehensive Genetic Services. Whole-exome sequencing (WES) was used to discover the underlying genetic etiology of participants' problems, and Sanger sequencing was utilized to confirm any suspected alterations. We also conducted a comprehensive molecular literature review to outline the genetic features of the various subtypes of PCH. RESULTS: This study classified and described the underlying etiology of PCH into three categories based on the genes involved. Twelve patients also were included, eleven of whom were from consanguineous parents. Ten different variations in 8 genes were found, all of which related to different types of PCH. Six novel variations were reported, including SEPSECS, TSEN2, TSEN54, AMPD2, TOE1, and CLP1. Almost all patients presented with developmental delay, hypotonia, seizure, and microcephaly being common features. Strabismus and elevation in lactate levels in MR spectroscopy were novel phenotypes for the first time in PCH types 7 and 9. CONCLUSIONS: This study merges previously documented phenotypes and genotypes with unique novel ones. Due to the diversity in PCH, we provided guidance for detecting and diagnosing these heterogeneous groups of disorders. Moreover, since certain critical conditions, such as spinal muscular atrophy, can be a differential diagnosis, providing cases with novel variations and clinical findings could further expand the genetic and clinical spectrum of these diseases and help in better diagnosis. Therefore, six novel genetic variants and novel clinical and paraclinical findings have been reported for the first time. Further studies are needed to elucidate the underlying mechanisms and potential therapeutic targets for PCH.

Ophthalmic manifestations of biotinidase deficiency: report of a case and review of literature.

INTRODUCTION: Biotinidase deficiency (BD) is an inherited autosomal recessive metabolic disorder. BD has been associated with optic nerve atrophy, eye infections, and retinopathy. The most prevalent ophthalmic manifestation of BD is optic atrophy, which might be misdiagnosed as multiple sclerosis or neuromyelitis optica, especially in late-onset BD cases. METHODS: In this article, we report a 9-year-old boy with gradual vision loss. Ophthalmologic examination, Brain MRI, and several laboratory tests such as Aquaporin-4 IgG level and biotinidase level were done on the patient. RESULTS: Bilateral optic atrophy and impaired visual acuity were detected on examination. The patient had a biotin level of 1.25 U/min/ml (normal range 3-9 U/min/ml), favoring the BD. CONCLUSION: In this study, we report a 9-year-old boy with vision loss diagnosed with BD. We also reviewed the literature to highlight the ophthalmic manifestations of BD. Ophthalmologists must consider BD in children with unexplained ophthalmologic complaints, especially when other characteristic signs of BD (e.g., developmental delay, seizure) are present. Also, patients with BD should undergo regular annual ophthalmologic examinations to be checked for any signs of eye involvement.

Comparing Pregabalin and Sodium Valproate in Pediatric Migraine Prophylaxis: A Randomized Clinical Trial.

Objectives: Migraine is a common disorder in children, and its prophylaxis with minimal side effects is momentous. This study aimed to compare the efficacy of Pregabalin and Sodium Valproate in preventing migraine attacks. Material & methods: Sixty-four children (aged 6-18) with migraines were recruited, as defined by Internation Headache Criteria (ICHD-III). They were randomly assigned to two groups: Sodium Valproate (n=32) and Pregabalin (n=32). The minimum dosage of drugs was prescribed in both groups. The patients were followed for four months. The parameters such as frequency, intensity, duration of migraine attacks, and the number of painkillers that the patients used monthly were recorded. The Spence Children's anxiety scale was also used to evaluate medications' effect on patients' anxiety levels. Results: Two medications were equally effective in reducing the intensity and duration of attacks. Additionally, their effect on reducing the anxiety level of patients was equal. There was a significant difference between the effect of drugs on the frequency of migraine attacks at the end of the first and fourth months and the number of painkillers used at the end of the fourth month. The frequency of attacks was decreased by more than 50% in twenty-eight patients (90%) of Pregabalin recipients and twenty-one patients (84%) of Sodium Valproate recipients. Conclusion: Considering the better effect of Pregabalin in the reduction of frequency of migraine attacks and pain-reducing medications consumption, Pregabalin could be a proper substitute for Sodium Valproate for prophylactic migraine treatment in children.

Megaconial congenital muscular dystrophy due to CHKB gene variants, the first report of thirteen Iranian patients.

Megaconial congenital muscular dystrophy (OMIM: 602,541) related to CHKB gene mutation is a newly defined rare autosomal recessive disorder, with multisystem involvement presenting from the neonatal period to adolescence. Choline kinase beta, lipid transport enzyme, catalyzes the biosynthesis of phosphatidylcholine and phosphatidylethanolamine, two major components of the mitochondrial membrane, on which respiratory enzyme activities are dependent. CHKB gene variants lead to loss-of-function of choline kinase b and lipid metabolism defects and mitochondrial structural changes. To date, many megaconial congenital muscular dystrophy cases due to CHKB gene variants have been reported worldwide. We describe thirteen Iranian megaconial congenital muscular dystrophy cases related to CHKB gene variants, including clinical presentations, laboratory and muscle biopsy findings, and novel CHKB gene variants. The most common symptoms and signs included intellectual disability, delayed gross-motor developmental milestones, language skills problems, muscle weakness, as well as autistic features, and behavioral problems. Muscle biopsy examination showed the striking finding of peripheral arrangements of large mitochondria in muscle fibers and central sarcoplasmic areas devoid of mitochondria. Eleven different CHKB gene variants including six novel variants were found in our patients. Despite the rarity of this disorder, recognition of the multisystem clinical presentations combined with characteristic findings of muscle histology can properly guide to genetic evaluation of CHKB gene.

Alopecia areata-like pattern of baldness: the most recent update and the expansion of novel phenotype and genotype in the CTNNB1 gene.

Neurodevelopmental disorder with spastic diplegia and visual defects (NEDSDV) is a rare autosomal dominant genetic disorder caused by genetic alterations in the CTNNB1 gene. CTNNB1 is a gene that encodes ß-catenin, an effector protein in the canonical Wnt pathway involved in stem cell differentiation and proliferation, synaptogenesis, and a wide range of essential cellular mechanisms. Mutations in this gene are also found in specific malignancies as well as exudative vitreoretinopathy. To date, only a limited number of cases of this disease have been reported, and though they share some phenotypic manifestations such as intellectual disability, developmental delay, microcephaly, behavioral abnormalities, and dystonia, the variety of phenotypic traits of these patients shows extreme heterogeneity. In this study, two cases of NEDSDV with de novo CTNNB1 mutations: c.1420C>T(p.R474X) and c.1377_1378Del(p.Ala460Serfs*29), found with whole exome sequencing (WES) have been reported and the clinical and paraclinical characteristics of these patients have been described. Due to such a wide range of clinical characteristics, the identification of new patients and novel variants is of great importance in order to establish a more complete phenotypic spectrum, as well as to conclude the genotype-phenotype correlations in these cases.

Clinical and genetic characterization of neuronal ceroid lipofuscinoses (NCLs) in 29 Iranian patients: identification of 11 novel mutations.

Neuronal ceroid lipofuscinoses (NCLs) are neurodegenerative lysosomal storage diseases which are considered among the most frequent causes of dementia in childhood worldwide This study aimed to identify the gene variants, molecular etiologies, and clinical features in 23 unrelated Iranian families with NCL. In total, 29 patients with neuronal ceroid lipofuscinoses (NCLs), diagnosed based on clinical manifestations, MRI neuroimaging, and electroencephalography (EEG), were recruited for this study. Through whole-exome sequencing (WES), functional prediction, Sanger sequencing, and segregation analysis, we found that 12 patients (41.3%) with mutations in the CLN6 gene, 7 patients (24%) with the TPP1 (CLN2) gene variants, and 4 patients (13.7%) with mutations in the MFSD8 (CLN7) gene. Also, mutations in each of the CLN3 and CLN5 genes were detected in 2 cases and mutations of each PPT1 (CLN1) and CLN8 gene were observed in only 1 separate patient. We identified 18 different mutations, 11 (61%) of which are novel, never have been reported before, and the others have been previously described. The gene variants identified in this study expand the number of published clinical cases and the variant frequency spectrum of the neuronal ceroid lipofuscinoses (NCLs) genes; moreover, the identification of these variants supplies foundational clues for future NCL diagnosis and therapy.

Neuroimaging Findings of the High-risk Neonates and Infants Referred to Mofid Children's Hospital.

Objectives: Neuroimaging in high-risk neonates and infants is done to help child neurologists predict the future neurodevelopmental outcome of these children. In this study, we assessed high-risk neonates and infants admitted to the NICU or neonatal wards of Mofid children's Hospital, especially regarding clinical development and brain imaging. Materials & Methods: This cross-sectional study was conducted on 170 patients admitted to the neonatal and NICU ward of Mofid children's Hospital. Considering the inclusion criteria, 112 patients were included in this project. Brain ultrasonography was performed on almost all of these babies by a single radiologist. Some patients underwent a brain CT scan, and brain MRI without contrast was done on the others. These images were interpreted and compared by a single pediatric neuro-radiologist blinded to clinical data. All of these babies were followed up until 18 months of age. Results: In this study, 57.1% of the patients were male and 42.9% were female. Of 44 patients who obtained Electroencephalogram (EEG) during the hospitalization period with probable seizure, 25 (56.8%) had normal EEGs. Of 89 babies who were examined by ultrasound, 19 (21.3%) had abnormal findings; ventriculomegaly and then germinal matrix hemorrhage (GMH) were the most common abnormalities. Also, 27 cases (71.1%) of 38 patients undergoing a CT scan had abnormal findings. The most common findings were a hypodense area in the white matter and ventriculomegaly. Of 41 patients who underwent MRI between 1 and 27 months, 34 cases (82.9%) had an abnormal MRI. The most common findings were periventricular hyperintensities in 17 cases (41.5%), mildly delayed myelination in 15 cases (36.6%), and severe brain atrophy or thinning of corpus callosum or white matter volume loss in seven cases (17.1%). During the follow-up period, which was 18.55 ± 6.56 months, 79 (70.5%) of the children had normal development and 33 (29.5%) were suffering from a global neurodevelopmental delay. More precisely, 49 (43.7%) and 35 (31.2%) patients had motor development delay and delayed verbal development, respectively. The abnormal findings of brain imaging in the ultrasound, CT scan, and MRI were all significantly associated with an adverse neurodevelopmental outcome (P <0.001, P = 0.02, and P <0.001, respectively). Conclusion: In this study, we showed that at any time before six months or after one year of age, the result of brain MRI was a strong predictor of the patient's outcome.

Five patients with spinal muscular atrophy-progressive myoclonic epilepsy (SMA-PME): a novel pathogenic variant, treatment and review of the literature.

Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME) is a rare inherited autosomal recessive disease due to bi-allelic mutations in the ASAH1 gene. SMA-PME is characterized by progressive muscle weakness from three to seven years of age, accompanied by epilepsy, intractable seizures, and sometimes sensorineural hearing loss. To the best of our knowledge, 47 cases have been reported. The present study reports five patients from four different families affected by SMA-PME characterized by progressive myoclonic epilepsy, proximal weakness, and lower motor neuron disease, as proven by electrodiagnostic studies. Genetic analysis identified two different mutations in the ASAH1 (NM_177924.4) gene, a previously reported pathogenic variant, c.125C>T (p.Thr42Met), and a novel likely pathogenic variant c.109C>A (p.Pro37Thr). In addition to reporting a novel pathogenic variant in the ASAH1 gene causing SMA-PME disease, this study compares the signs, phenotypic, and genetic findings of the case series with previous reports and discusses some symptomatic treatments.

Neurodegenerative disorder and diffuse brain calcifications due to FARSB mutation in two siblings.

Pathogenic mutations in the FARSB gene are associated with neurodevelopmental disorder involving the brain, liver, and lungs. We report genetic analysis of a family including two affected members with this disorder, which revealed a homozygous pathogenic missense variant, FARSB: NM_005687.4:c.853G > A:p.E285K in both affected patients. The parents were heterozygous for this variant.

Identification of novel mutations among Iranian NPC1 patients: a bioinformatics approach to predict pathogenic mutations.

BACKGROUND: Niemann-Pick disease type C (NPC) is a rare lysosomal neurovisceral storage disease caused by mutations in the NPC 1 (95%) or NPC2 (5%) genes. The products of NPC1 and NPC2 genes play considerable roles in glycolipid and cholesterol trafficking, which could consequently lead to NPC disease with variable phenotypes displaying a broad spectrum of symptoms. MATERIALS: In the present study 35 Iranian NPC unrelated patients were enrolled. These patients were first analysed by the Filipin Staining test of cholesterol deposits in cells for NPC diagnostics. Genomic DNA was extracted from the samples of peripheral blood leukocytes in EDTA following the manufacturer's protocol. All exon-intron boundaries and coding exons of the NPC1gene were amplified by polymerase chain reaction (PCR) using appropriate sets of primers. Thereafter, the products of PCR were sequenced and analysed using the NCBI database ( https://blast.ncbi.nlm.nih.gov/Blast.cgi ). The variants were reviewed by some databases including the Human Gene Mutation Database (HGMD) ( http://www.hgmd.cf.ac.uk/ac/index.php ) and ClinVar ( https://www.ncbi.nlm.nih.gov/clinvar (. Moreover, all the variants were manually classified in terms of the American College of Medical Genetics and Genomics (ACMG) guideline. RESULTS: The sequence analysis revealed 20 different variations, 10 of which are new, including one nonsense mutation (c.406C > T); three small deletions, (c.3126delC, c.2920_2923delCCTG, and c.2037delG); and six likely pathogenic missense mutations, (c.542C > A, c.1970G > A, c.1993C > G, c.2821 T > C, c.2872C > G, and c.3632 T > A). Finally, the pathogenicity of these new variants was determined using the ACMG guidelines. CONCLUSION: The present study aimed to facilitate the prenatal diagnosis of NPC patients in the future. In this regard, we identified 10 novel mutations, and verified that the majority of them occurred in six NPC1 exons (5, 8, 9, 13, 19, and 21), that should be considered with a high priority for Iranian patients' cost-effective evaluation.

Analysis of the HEXA, HEXB, ARSA, and SMPD1 Genes in 68 Iranian Patients.

Lysosomal storage diseases (LSDs) are known as genetic disorders with an overall prevalence of 1 per 7700 live births. Sphingolipidosis, which is a subgroup of LSDs, is resulted from mutations in the coding genes of specific enzymes of sphingolipid hydrolases. The current study aimed to provide additional knowledge on the genotype of sphingolipidoses disease among Iranian patients affected by the disease. In this research, we studied 68 unrelated Iranian patients diagnosed with one kind of sphingolipidoses from 2014 to 2019. Thereafter, genomic DNA was isolated from their peripheral blood leukocytes samples in EDTA in terms of the manufacturer's protocol. All the coding exons and exon-intron boundaries of the related genes were sequenced and then analyzed using the NCBI database. Finally, they were reviewed using some databases such as the Human Gene Mutation Database (HGMD) and ClinVar ( https://www.ncbi.nlm.nih.gov/clinva ). By studying 22 MLD patients, 18 different variations of the ARSA gene were found, one of which was new including, named as c.472 T > G p. (Cys158Gly). Out of 15 Sandhoff disease (SD) patients, 11 different variations of the HEXB gene were found. Correspondingly, the c.1083-2delA was not reported earlier. By investigating 21 Iranian patients with Tay-Sachs disease (TSD), one new variant was found as c.622delG. The study of 10 Niemann-Pick disease A/B (NPDA/B (patients has led to the identification of 9 different SMPD1 gene variations, among which 3 variations were novel mutations. The results of the present study can be expanded to the genotypic spectrum of Iranian patients with MLD, SD, TSD, and NPD diseases and also used to innovate more effective methods for the detection of genetic carriers as well as diagnosing and counseling of Iranian patients affected with these disorders.

Characterizing Genotypes and Phenotypes Associated with Dysfunction of Channel-Encoding Genes in a Cohort of Patients with Intellectual Disability.

BACKGROUND: Ion channel dysfunction in the brain can lead to impairment of neuronal membranes and generate several neurological diseases, especially neurodevelopmental disorders. METHODS: In this study, we set out to delineate the genotype and phenotype spectrums of 14 Iranian patients from 7 families with intellectual disability (ID) and/or developmental delay (DD) in whom genetic mutations were identified by next-generation sequencing (NGS) in 7 channel-encoding genes: KCNJ10, KCNQ3, KCNK6, CACNA1C, CACNA1G, SCN8A, and GRIN2B. Moreover, the data of 340 previously fully reported ID and/or DD cases with a mutation in any of these seven genes were combined with our patients to clarify the genotype and phenotype spectrum in this group. RESULTS: In total, the most common phenotypes in 354 cases with ID/DD in whom mutation in any of these 7 channel-encoding genes was identified were as follows: ID (77.4%), seizure (69.8%), DD (59.8%), behavioral abnormality (29.9%), hypotonia (21.7%), speech disorder (21.5%), gait disturbance (20.9%), and ataxia (20.3%). Electroencephalography abnormality (33.9%) was the major brain imaging abnormality. CONCLUSION: The results of this study broaden the molecular spectrum of channel pathogenic variants associated with different clinical presentations in individuals with ID and/or DD.

A case of diffuse leptomeningeal glioneuronal tumor in a 10-year-old boy: First report from Iran.

A 10-year-old boy who was referred due to acute hydrocephalus symptoms was diagnosed as the first case of pediatric DLGNT in Iran. The results suggested that using shunting for hydrocephaly and anti-seizure medicines, as well as chemotherapeutic agents, can be an effective treatment strategy for DLGNT. Although the patient was stable without a tumor recurrence for a limited follow-up period of 22 months, further studies are expected.

Succinate Dehydrogenase Deficiency: A Treatable Neurometabolic Disorder.

Succinate dehydrogenase (SDH) deficiency is a rare autosomal recessive neurometabolic disorder that causes brain insult, neurodevelopmental delay, exercise intolerance, and cardiomyopathy. A 25-month-old boy was referred to our neurometabolic center due to developmental regression after injecting the influenza vaccine when he was 10 months old. Magnetic resonance imaging (MRI) showed high signal changes in the brain white matter, and magnetic resonance spectroscopy (MRS) detected a high succinate peak at 2.4 parts per million (ppm). The evaluation of urine organic acids showed a significant elevated succinic acid and whole exome sequencing, confirming SDH. Treatment with a mitochondrial cocktail was initiated, and remarkable improvement was observed. SDH deficiency as a treatable neurometabolic disorder should be considered in any patients with developmental disorders, accompanied by hyperintensity in white matter (as similar to leukodystrophia). Further evaluation is recommended since outcomes depend on early diagnosis and treatment.

Approach to Patients with Neurometabolic Diseases Who Show Characteristic Signs and Symptoms.

Neurometabolic disorders are hereditary conditions mainly affect the function of the brain and the nervous system. The prevalence of these disorders is 1 in 1,000 live births. Such disorders, at different ages, could manifest as sepsis, hypoglycemia, and other neurologic disorders. Having similar manifestations leads to delayed diagnosis of neurometabolic disorders. A number of neurometabolic disorders have known treatments; however, to prevent long-term complications the key factors are early diagnosis and treatment. Although a large number of neurometabolic diseases have no treatment or cure, the correct and on-time diagnosis before death is important for parents to have plans for prenatal diagnosis. Different diagnostic procedures could be offered to parents, enzymatic procedures, and determining metabolites in plasma, urine, and CSF, and molecular genetic diagnosis. Molecular genetic diagnostic procedures are expensive and could not be offered to all parents. Therefore, we aimed to design algorithms to diagnose neurometabolic disorders according to some frequent and characteristic signs and symptoms. By designing these algorithms and using them properly, we could offer diagnostic enzymatic panels. These enzymatic panels are inexpensive; thereby reducing the financial burden on the parents. Also, having an early diagnosis according to these panels could lead to offering more accurate and less expensive molecular genetic tests.