Therapeutic implications of etiology-specific diagnosis of early-onset developmental and epileptic encephalopathies (EO-DEEs): A nationwide Turkish cohort study.

OBJECTIVE: To evaluate the etiology-specific diagnosis of early-onset developmental epileptic encephalopathies (EO-DEEs) in a nationwide Turkish cohort to determine the implications for therapeutic management. METHODS: The cohort comprised 1450 patients who underwent EO-DEE. The utility of genetic testing was assessed with respect to the initial phases of next generation sequencing (NGS) (2005-2013) and the current NGS era (2014-2022). A predefined four-stepwise diagnostic model was evaluated using cost-effectiveness analysis. The diagnostic and potential therapeutic yields of the genetic tests were subsequently determined. RESULTS: Gene-related EO-DEEs were identified in 48.3 % (n = 701) of the cohort: non-structural genetic (62.6 %), metabolic genetic (15.1 %), and structural genetic (14.1 %). The most common nonstructural genetic variants were SCN1A (n = 132, 18.8 %), CDKL5 (n = 30, 4.2 %), STXBP1 (n = 21, 2.9 %), KCNQ2 (n = 21, 2.9 %), and PCDH19 (n = 17, 2.4 %). The rate of ultra-rare variants (< 0.5 %) was higher in the NGS era (52 %) than that in the initial phase (36 %). The potential therapeutic yields with precision therapy and antiseizure drug modification were defined in 34.5 % and 56.2 % in genetic-EO-DEEs, respectively. The diagnostic model provided an etiology-specific diagnosis at a rate of 78.7 %: structural (nongenetic) (31.4 %), genetic (38.5 %), metabolic (6.1 %), and immune-infectious (2.8 %). Based on a cost-effectiveness analysis, the presented diagnostic model indicated the early implementation of whole-exome sequencing for EO-DEEs. SIGNIFICANCE: In the present cohort, the higher rate (48.3 %) of gene-related EO-DEE diagnoses in the NGS era provides a potential therapeutic management plan for more patients.

Evaluation of seizure semiology, genetics, magnetic resonance imaging, and electroencephalogram findings in children with Rett syndrome: A multicenter retrospective study.

OBJECTIVES: This study aimed to evaluate seizure semiology, electroencephalogram (EEG), magnetic resonance imaging (MRI), and genetic findings, as well as treatment choices in Rett syndrome (RTT). METHODS: A retrospective analysis was conducted on one hundred and twenty cases diagnosed with RTT with a genetic mutation. Data were obtained from nine participating centers. RESULTS: In this study, 93.3 % of patients were female, with typical RTT found in 70 % of cases. Genetic etiology revealed MECP2, FoxG1, and CDKL5 in 93.8 %, 2.7 %, and 1.8 % of cases, respectively. Atypical RTT clinics were observed in 50 % of male cases, with the first EEG being normal in atypical RTT cases (p = 0.01). Generalized tonic-clonic and myoclonic epilepsy were the most common seizure semiologies, while absence and focal epilepsy were less prevalent. Valproate, levetiracetam, lamotrigine, and clobazam were the most commonly used antiepileptic drugs, affecting the severity and frequency of seizures (p = 0.015, p=<0.001, p = 0.022, and p=<0.001, respectively). No significant differences were observed in EEG findings. The initiation of anti-seizure medications significantly altered seizure characteristics (Table 4). A ketogenic diet and vagal nerve stimulation (VNS) correlated with a 50 % improvement in cognitive function, while steroid treatment showed a 60 % improvement. Remarkably, seizures were substantially reduced after VNS application. CONCLUSION: This study underscores the importance of genetic diagnosis in RTT cases with a clinical diagnosis. These preliminary results will be further validated with the inclusion of clinically diagnosed RTT cases in our ongoing study.

A Homozygous Missense Variant in HSD17B4 Identified in Two Different Families.

Background: Perrault syndrome is an inherited disorder with clinical findings that differ according to sex. It is characterized by a variable age of onset and sensorineural hearing loss in both sexes, as well as ovarian dysfunction in females with a 46,XX karyotype. Although it is a rare autosomal recessive syndrome, with approximately 100 affected individuals reported in the literature, it shows both genotypic and phenotypic variations. Mutations in the HSD17B4 gene have been identified as one of the genetic causes of Perrault syndrome. Case Presentation: A female case and a male case from two different unrelated families with a new variant in the HSD17B4 gene, which were not previously described in the literature and were accompanied by hearing loss, skeletal anomalies, and neurological symptoms, were presented. Conclusion: We defined Perrault syndrome cases in Turkey caused by a novel mutation in HSD17B4. Whole-exome sequencing is a useful diagnostic technique with varying clinical results due to genetic and phenotypic heterogeneity.

A Multicenter Study of Self-Limited Epilepsy With Centrotemporal Spikes: Effectiveness of Antiseizure Medication With Respect to Spike-Wave Index.

BACKGROUND: There is no certain validated electroencephalographic (EEG) parameters for outcome prediction in children with self-limited epilepsy with centrotemporal spikes. To assess the effectiveness of antiseizure medication (ASM) for seizure outcome with respect to the spike-wave index (SWI) on serial EEG recordings. METHODS: In this multicenter study, the study cohort consisted of 604 children with self-limited epilepsy with centrotemporal spikes. A data set of epilepsy centers follow-up between 2010 and 2022. The cohort was divided into 4 groups as those receiving 3 different monotherapy (carbamazepine [CBZ]/valproic acid [VPA]/levetiracetam [LEV]) and dual therapy. SWI analysis was performed with the percent of spikes in the 2-minute epoch in the 5th 6th minutes of the nonrapid eye movement sleep EEG record. The study group were also categorized according to seizure burden with seizure frequency (I) >2 seizures and (II) >5 seizures. Seizure outcome was evaluated based on the reduction in seizure frequency over 6-month periods: (1) 50% reduction and (2) seizure-free (complete response). RESULTS: ASM monotherapy was achieved in 74.5% children with VPA, CBZ, and LEV with similar rates of 85.8%, 85.7%, and 77.9%. Dual therapy was need in the 25.5% of children with SeLECT. More dual therapy was administered in children aged below 5 years with a rate of 46.2%. Earlier seizure-free achievement time was seen in children with LEV monotherapy with more complete-response rate (86.7%) compared the VPA and CBZ. CONCLUSIONS: We also determined that the children on dual therapy had more SWI clearance in the subsequent EEG recordings. The ROC curve analyses were performed to predict initial drug selection with using the SWI% might be used for the prediction of ASM type and drug selection in children.

Optic neuritis in Turkish children and adolescents: A multicenter retrospective study.

BACKGROUND: Various etiologies may underlie optic neuritis, including autoantibody-mediated disorders described in the last decade. We re-examined demographic, clinical, laboratory features and prognostic factors in pediatric patients with autoimmune optic neuritis according to current knowledge. METHODS: Cases of pediatric ON from 27 centers in Türkiye diagnosed between 2009 and 2022 were included for retrospective evaluation. RESULTS: The study included 279 patients, 174 females and 105 males, with a female-to-male ratio of 1.65. The average age at onset was 12.8 ± 3.4 years, and mean follow-up, 2.1 years (range: 1-12.1 years). Patients <10 years old were grouped as "prepubertal" and those ≥10 years old as "others". The diagnoses made at the end of follow-up were multiple sclerosis associated optic neuritis (n = 90, 32.3 %), single isolated optic neuritis (n = 86, 31 %), clinically isolated syndrome (n = 41, 14.7 %), myelin oligodendrocyte glycoprotein antibody associated optic neuritis (n = 22, 7.9 %), and relapsing isolated optic neuritis (n = 18, 6.5 %). Predominant diagnoses were myelin oligodendrocyte glycoprotein antibody associated optic neuritis and acute disseminated encephalomyelitis associated optic neuritis in the prepubertal group and multiple sclerosis associated optic neuritis in the older group. Recurrences were observed in 67 (24 %) patients, including 28 with multiple sclerosis associated optic neuritis, 18 with relapsing isolated optic neuritis, 11 with myelin oligodendrocyte glycoprotein antibody associated optic neuritis, 8 with aquaporin-4 antibody related optic neuritis, and 2 with chronic relapsing inflammatory optic neuropathy. Recurrences were more common among female patients. Findings supporting the diagnosis of multiple sclerosis included age of onset ≥ 10 years (OR=1.24, p = 0.027), the presence of cranial MRI lesions (OR=26.92, p<0.001), and oligoclonal bands (OR=9.7, p = 0.001). Treatment in the acute phase consisted of intravenous pulse methylprednisolone (n = 46, 16.5 %), pulse methylprednisolone with an oral taper (n = 212, 76 %), and combinations of pulse methylprednisolone, plasmapheresis, or intravenous immunoglobulin (n = 21, 7.5 %). Outcome at 12 months was satisfactory, with 247 out of 279 patients (88.5 %) demonstrating complete recovery. Thirty-two patients exhibited incomplete recovery and further combination treatments were applied. Specifically, patients with relapsing isolated optic neuritis and aquaporin-4 antibody related optic neuritis displayed a less favorable prognosis. CONCLUSION: Our results suggest optic neuritis is frequently bilateral in prepubertal and unilateral in peri­ or postpubertal patients. Age of onset 10 or older, presence of oligoclonal bands, and brain MRI findings reliably predict the development of multiple sclerosis. The risk of developing multiple sclerosis increases mostly during the second and third years of follow-up. Relapsing isolated optic neuritis remains a separate group where the pathogenesis and outcome remain unclear. Investigation of predisposing and diagnostic biomarkers and long follow-up could help to define this group.

A novel INPP4A mutation with pontocerebellar hypoplasia, myoclonic epilepsy, microcephaly, and severe developmental delay.

BACKGROUND: The inositol polyphosphate 4-phosphatase intracellular signaling pathway is susceptible to genetic or epigenetic alterations that may result in major neurological illnesses with clinically significant pons and cerebellum involvement. CASE REPORTS: A seven-year-old girl with pontocerebellar hypoplasia, resistant myoclonic epilepsy with axial hypotonia, microcephaly, atypical facial appearance, nystagmus, ophthalmoplegia, hyperactive tendon reflexes, spasticity, clonus, extensor plantar response, contractures in wrists and ankles and growth retardation, whole-exome sequencing was performed and a homozygous "NM_001134225.2:c.646C > T, p.(Arg216Ter)" variant was found in the INPP4A gene. CONCLUSION: INPP4A mutations should be kept in mind in cases with severely delayed psychomotor development, progressive microcephaly, resistant myoclonic epilepsy, isolated cerebellum, and pons involvement.

Shared Biological Pathways and Processes in Patients with Intellectual Disability: A Multicenter Study.

BACKGROUND: Although the underlying genetic causes of intellectual disability (ID) continue to be rapidly identified, the biological pathways and processes that could be targets for a potential molecular therapy are not yet known. This study aimed to identify ID-related shared pathways and processes utilizing enrichment analyses. METHODS: In this multicenter study, causative genes of patients with ID were used as input for Disease Ontology (DO), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. RESULTS: Genetic test results of 720 patients from 27 centers were obtained. Patients with chromosomal deletion/duplication, non-ID genes, novel genes, and results with changes in more than one gene were excluded. A total of 558 patients with 341 different causative genes were included in the study. Pathway-based enrichment analysis of the ID-related genes via ClusterProfiler revealed 18 shared pathways, with lysine degradation and nicotine addiction being the most common. The most common of the 25 overrepresented DO terms was ID. The most frequently overrepresented GO biological process, cellular component, and molecular function terms were regulation of membrane potential, ion channel complex, and voltage-gated ion channel activity/voltage-gated channel activity, respectively. CONCLUSION: Lysine degradation, nicotine addiction, and thyroid hormone signaling pathways are well-suited to be research areas for the discovery of new targeted therapies in ID patients.

The effectiveness and tolerability of clobazam in the pediatric population: Adjunctive therapy and monotherapy in a large-cohort multicenter study.

OBJECTIVE: To evaluate the effectiveness and tolerability of clobazam therapy in the pediatric population in terms of seizure semiology, epileptic syndromes, and etiological subgroups. METHODS: A retrospective cohort study was conducted consisting of 1710 epileptic children from eight centers in seven geographic regions of Turkey. The initial efficacy of clobazam therapy was evaluated after three months of treatment. The long-term effectiveness of the drug, overall seizure outcomes, and overall therapeutic outcomes were evaluated during 12 months of therapy. RESULTS: Analysis of initial efficacy after the first three months of clobazam therapy showed that 320 (18.7 %) patients were seizure-free, 683 (39.9 %) had > 50 % seizure reductions, and 297 (17.4 %) had < 50 % seizure reductions. A positive response (seizure-free and >50 % seizure reduction) was determined for focal-onset (62.3 %) seizures, epileptic spasms (61.5 %), and generalized onset seisures (57.4). The highest positive response rate among the epileptic syndromes was for self-limited epilepsy with centrotemporal spikes (SeLECTS). The highest negative response rate was for developmental and/or epileptic encephalopathies (DEEs). Magnetic resonance imaging (MRI) revealed a structural etiological diagnosis in 25.8 % of the cohort. A higher positive response rate was observed at MRI in patients with sequelae lesions than in those with congenital lesions. The seizure recurrence rate was higher in the patient group with epilepsy with genetic and metabolic causes, in individuals with more than one seizure type, and in those using three or more antiseizure drugs. CONCLUSIONS: This cohort study provides additional evidence that clobazam is an effective and well-tolerable drug with a high seizure-free rate (18.7 %), a significant seizure reduction rate (57.3 %), and with excellent overall therapeutic outcomes with a low seizure relapse rate and considerable reversible benefits in the pediatric population.

An investigation of the effects of chronic zonisamide, sultiam, lacosamide, clobazam, and rufinamide anti-seizure medications on foliculogenesis in ovarian tissue in prepubertal non-epileptic rats.

We aimed to determine the morphological and histological effects of zonisamide, sultiam, lacosamide, clobazam, and rufinamide on ovarian folliculogenesis in rats. Sixty female Wistar rats were divided into six experimental groups as control, zonisamide, sultiam, lacosamide, clobazam, and rufinamide groups; control solution and drugs were administered by gavage for 90 days. The number of healthy follicles in the control group was significantly higher than in the anti-medication groups (p < 0.001), and the number of corpus luteum was significantly lower (p < 0.001). There was a significant difference in the number of TUNEL positive apoptotic follicles between the control and drug groups (p < 0.001). With EGF, IGF-1, and GDF-9 staining, a very strong immunoreaction was observed in the ovarian multilaminar primary follicle granulosa cells and oocytes in the control group compared to the drug group (p < 0.001). Long-term anti-seizure medication with zonisamide, sultiam, lacosamide, clobazam, and rufinamide from prepubertal to adulthood causes apoptosis and disruption of folliculogenesis in the ovarian follicles of nonepileptic rats.

An Investigation of Changing Attitudes and Behaviors and Problematic Internet Use in Children Aged 8 to 17 Years During the COVID-19 Pandemic.

PURPOSE: To examine the effects of the COVID-19 pandemic on the lifestyle, habits, and behavioral differences in children, and their changing internet use habits. METHODS: The research was planned as a cross-sectional study involving 4892 children aged 8 to 17 years attending schools in the city center of Trabzon, Turkey. Children's daily living activities, social habits, mood and temperament changes, and internet use were investigated before and during the pandemic. In terms of problematic internet use, internet addiction rates were evaluated using the validated Turkish-language version of the Parent-Child Internet Addiction Scale (PCIAT-20). RESULTS: The children's mean age was 13 ± 2.45 years, and 17.1% (n = 837) exhibited problematic internet use features on the PCIAT-20. Problematic internet use was higher in boys and in children older than 13 years. The presence of COVID-19 infection among members of the household, quarantine measures, attending private schools, the mother's occupation, the time spent by the mother and father on their mobile phones, and high parental education levels were associated with a high level of internet addiction. Families also described significant changes in their children's temperament and character compared with the pre-pandemic period. CONCLUSION: The prevalence of problematic internet use increased during the COVID-19 pandemic compared with previous studies from Turkey. Children were also more introverted, irritable, and pessimistic during the pandemic.

SLC26A3 mutation in Turkish neonate and her sibling with congenital chloride diarrhea.

Congenital chloride diarrhea is a rare cause of severe infantile diarrhea with excessive chloride excretion. Mutations in the SLC26A3 gene cause congenital chloride diarrhea. It generally becomes apparent in the neonatal period and is characterized by electrolyte imbalances, metabolic alkalosis, and failure to thrive. The diagnosis of congenital chloride diarrhea is based on detecting excessive chloride in the stool (90 mmol/L). We report a Turkish neonate with congenital chloride diarrhea whose sibling had the same disease. The newborn was born by cesarean delivery. Diarrhea, vomiting, and weight loss started soon after birth. She was diagnosed as having congenital chloride diarrhea based on its typical clinical signs and a high concentration of stool chloride and was confirmed by genetic analysis. She was treated by means of salt supplementations and lansoprazole. Family history may play an important role in the early diagnosis because the disease is inherited autosomal recessively.