Characterization of 13 Novel Genetic Variants in Genes Associated with Epilepsy: Implications for Targeted Therapeutic Strategies.

BACKGROUND: Childhood epilepsies are caused by heterogeneous underlying disorders where approximately 40% of the origins of epilepsy can be attributed to genetic factors. The application of next-generation sequencing (NGS) has revolutionized molecular diagnostics and has enabled the identification of disease-causing genes and variants in childhood epilepsies. The objective of this study was to use NGS to identify variants in patients with childhood epilepsy, to expand the variant spectrum and discover potential therapeutic targets. METHODS: In our study, 55 children with epilepsy of unknown etiology were analyzed by combining clinical-exome and whole-exome sequencing. Novel variants were characterized using various in silico algorithms for pathogenicity and structure prediction. RESULTS: The molecular genetic cause of epilepsy was identified in 28 patients and the overall diagnostic success rate was 50.9%. We identified variants in 22 different genes associated with epilepsy that correlate well with the described phenotype. SCN1A gene variants were found in five unrelated patients, while ALDH7A1 and KCNQ2 gene variants were found twice. In the other 19 genes, variants were found only in a single patient. This includes genes such as ASH1L, CSNK2B, RHOBTB2, and SLC13A5, which have only recently been associated with epilepsy. Almost half of diagnosed patients (46.4%) carried novel variants. Interestingly, we identified variants in ALDH7A1, KCNQ2, PNPO, SCN1A, and SCN2A resulting in gene-directed therapy decisions for 11 children from our study, including four children who all carried novel SCN1A genetic variants. CONCLUSIONS: Described novel variants will contribute to a better understanding of the European genetic landscape, while insights into the genotype-phenotype correlation will contribute to a better understanding of childhood epilepsies worldwide. Given the expansion of molecular-based approaches, each newly identified genetic variant could become a potential therapeutic target.

Provoked seizures at the onset of progressive disease contribute to diagnosis delay - A tertiary center experience in a cohort of 22 children with CLN2.

PURPOSE: The evaluation of epilepsy features and factors with impact to diagnosis delay in children with CLN2. METHOD: The study included children with CLN2 treated from 2000 to 2020. Diagnosis was confirmed by: TPP1 deficiency and/or TPP1 gene mutation or pathognomonic electron microscopy findings. The seizure features were evaluated: the age of onset, provocation, semiology and EEG. The disease severity was assessed by CLN2 Clinical Rating Scale (CLN2-CRS). Statistical analysis included T test, chi-square test, Wilcoxon-Mann-Whitney test, using SPSS statistics 25. RESULT: The study included 22 children with CLN2. Seizures were experienced by all cases at the early stage of disease, preceded by language delay in 18, and behavior problems in 14 pts. The first seizure was provoked in 9 children at mean age of 33.8 ± 4.6 months, and unprovoked in 13 at mean age of 34.6 ± 2.7 months. In patients with provoked first seizure, the average period from the first seizure to diagnosis was longer (35.1 months), with lower CLN2-CRS, then in those with unprovoked (23.8 months) first seizures (p < 0.008). Initial seizures were generalized tonic-clonic (Pampiglione and Harden, 1973 Feb) [8], atonic (Pampiglione and Harden, 1973 Feb) [8], and focal (Beltrán et al., 2018 Aug) [4], with recurrence within two months. With progression, the patients experienced multiple seizure types, and 1/3 suffered status epilepticus. CONCLUSIONS: Provoked seizures at the onset of CLN2 have impact to diagnosis delay. The red flags are: preceding language delay and behavior problems, later FS onset comparing to the typical age, atonic, focal and long-lasting seizure, and recurrence of seizures within two months.

The improvement in diagnosis and epilepsy managing in children with progressive myoclonus epilepsy during the last decade - A tertiary center experience in cohort of 51 patients.

The aim of the study was to explore whether diagnosis and managing children with progressive myoclonus epilepsy (PME) were improved during the last decade. METHODS: The retrospective study included children with PME treated in the Institute during the last 25 years. Investigation time was divided in two periods (groups): before December 2010 (the first group) and after this period up to December 2019 (the second group). Inclusion criteria are as follows: patients aged from 0.2-18 years and with PME. Evaluated parameters are etiology, age at seizure onset, diagnosis delay, epilepsy phenotype, and, as a measure of epilepsy control - status epilepticus (SE) frequency and recurrence rate. Statistical analysis included the following tests: Chi-Square, Mann-Whitney, and analysis of variance (ANOVA), using SPSS version 25. RESULTS: The study included 51 patients, 27 in the first, and 24 in the second group. The underlying diseases were: neuronal ceroid lipofuscinosis (NCL; 30), Gaucher (5), Niemann-Pick (4), mitochondrial (4), Lafora (3), Krabbe (2), and KCNC1 gene mutation (2). The average duration from initial symptoms to diagnosis was 3.2 ±â€¯3 years (first group) vs. 1.4 ±â€¯0.9 years (second). Both SE frequency rate (55.5% vs. 37.5%) and recurrence rate (66.7% vs. 22.2%) were higher in the first group, showing tendency towards, but not statistically significant difference. CONCLUSION: The diagnosis and epilepsy managing children with PME were improved during the last decade. Earlier genetic diagnosis, appropriate antiseizure medications, education of parents/caregivers of children in high risk for SE, and availability of effective prehospital rescue medications contributed to significantly decreased frequency and recurrence rate of SE.

The features of neonatal seizures as predictors of drug-resistant epilepsy in children.

PURPOSE: The aim of this study was to evaluate the predictive value of the features of neonatal seizures for pharmacoresistant epilepsy in children. METHOD: This is a retrospective study that involved all children diagnosed as having epilepsy who had neonatal seizures and who were hospitalized at the Neurology Department of the Mother and Child Healthcare Institute in Belgrade from January the 1st 2017 until December 31st 2017. The following parameters and their impact on the outcome were investigated: perinatal data, the characteristics of epileptic seizures in the neonatal period, and the response to anticonvulsant treatment. The presence of pharmacoresistance was observed as an outcome parameter. Univariate and multivariate logistic regression analyses were used to define predictors of drug-resistant epilepsy. RESULTS: The study involved 55 children, 35 (63.6%) male and 20 (36.4%) female. The average age of the children at the end of the observation period was 5.17 years (min: 0.25, max: 17.75, iqr (interquartile range): 6.92). Pharmacoresistant epilepsy was found in 36 (65.5%) children. The most common type of epilepsy was focal, which affected 30 patients (54.5%), than generalized, which affected 15 patients (27.3%), and combined generalized and focal, which affected 8 patients (14.5%). At the end of the observation period, 28 patients (50.9%) had no seizures, while 14 (25.5%) had daily seizures. It was found that the pharmacoresistant neonatal seizures and metabolic-genetic disorders were predictive factors of the occurrence of pharmacoresistant epilepsy. CONCLUSION: Patients prone to developing pharmacoresistant epilepsy might be identified as early as the neonatal and early infant period. High incidence of asphyxia cooccurring with established genetic-metabolic disease further emphasizes need for genetic testing in infants with neonatal seizures including in the presence of hypoxic-ischemic injury.

New-onset seizure presenting as status epilepticus: Etiology and clinical characteristics in a cohort of 236 children.

PURPOSE: Evaluation of the etiology, clinical characteristics and outcome of the first status epilepticus (fSE) event in children. METHOD: The patients with fSE hospitalized in our Institute from 1995 to 2011 were included. The etiology was characterized as either known (symptomatic) or unknown (cryptogenic). Outcome was assessed at the end of hospitalization. Logistic regression analyses were used to assess predictors of the outcome, with odds ratio adjusted by age as a measure effect. RESULTS: The study included 236 patients with a median age of 2.0 years (IQR 4.0). Etiology was identified as secondary to: defined electroclinical syndromes 108 (45.8), acute symptomatic conditions 63 (26.7%), unknown 24 (10.1%), progressive encephalopathy 23 (9.7%), or remote symptomatic 18 (7.6%). Recurrence rate was 16.9%, neurological consequences were in 24.6% and case-fatality ratio was 4.7%. The main predictors were for: a) death - progressive encephalopathy (OR = 14.68, 95% CI 4.06-23.11. p = 0.001); b) neurological sequelae - acute symtomatic (OR 3.44, 95% CI 4.82-6.47) p = 0.001, remote symptomatic (OR = 13.84, 95% CI 4.34-44.12. p = 0.001), progressive encephalopathy (OR = 3.94, 95% CI 1.64-9.56. p = 0.002), seizure duration >60 min (OR = 0.44, 95% CI 0.24-0.81. p = 0.001); c) seziure recurrence - acute symptomatic etiology (OR = 3.59, 95% CI 41.76-7.21. p = 0.001), seizure duration >60 min (OR = 0.30, 95% CI 0.15-0.61. p = 0.001). CONCLUSIONS: In children with fSE, exploring acute disorders and immediate etiological treatment is essential. The outcome of fSE is favorable concerning the recurrence rate, while neurological sequelae are seen in one quarter of the patients. The etiology and fSE duration are the main determinants of outcome.

Long-term outcome in children with neonatal seizures: A tertiary center experience in cohort of 168 patients.

PURPOSE: The purpose of this study was to evaluate long-term outcome and assess predictors of prognosis in children with neonatal seizures (NS). METHOD: This retrospective study includes children with NS treated at our Institute from January the 1st 2005 until December the 31st 2015. The data were collected from medical charts and the electroencephalogram (EEG) database at the Institute. The predictive value was evaluated for following parameters: (1) characteristics of the patients, such as gender, gestational age, birth body weight, Apgar score, artificial ventilation; (2) etiology; (3) characteristics of seizures such as type, time of onset, resistance to treatment; and (4) EEG background activity and paroxysmal discharges. The outcome of NS was assessed at the end of the follow-up period and was categorized as one of the following: (1) lethal outcome, (2) neurological abnormalities, (3) intellectual disability, and (4) epilepsy. Univariate and multivariate logistic regression analyses were used to assess predictors of NS outcome. RESULTS: The study included 168 children with NS (of which 109 are males, and 59 are females), mean aged 5.6 (SD 3.5) years at the end of the follow-up (with a range of 1 to 12 years). There was normal neurological development without epilepsy in 131 patients (78%), neurological abnormality in 31 (19.0%), intellectual disability in 28 (17.2%), epilepsy in 12 (7.4%), and lethal outcome in 7 patients (4.17%). CONCLUSIONS: Long-term outcome in children with NS could be favorable in most patients, and it appears to be related to specific early clinical and paraclinical variables. Newborns with an abnormal background EEG activity, with seizures resistant to antiepileptic drugs and/or low Apgar score are at a higher risk of a poor outcome. Females are at a much higher risk of lethal outcome than males.

A 6-month follow-up of disability, quality of life, and depressive and anxiety symptoms in pediatric migraine with magnesium prophylaxis.

Magnesium is frequently used for pediatric migraine prophylaxis. The aim of this study was to evaluate to which extent the disability levels, quality of life (QOL), and anxiety and depressive symptoms change after 6-month magnesium prophylaxis in pediatric migraine. This is a follow-up study of 34 children aged 7-17 years with migraine treated with oral magnesium. Disability due to migraine was assessed by the Pediatric Migraine Disability Assessment tool (PedMIDAS), QOL was assessed by the KIDSCREEN-27, and anxiety and depressive symptoms were assessed by the Revised Child Anxiety and Depression Scale (RCADS). PedMIDAS scores significantly decreased from baseline to end-point (F(df, dferror) = 11.10 (1.63, 50.49), p<0.001), as well as anxiety (F(df, dferror) = 8.95 (1.64, 50.67), p = 0.001) and depressive symptoms (F(df, dferror) = 8.91 (1.59, 49.29), p = 0.001). Considering the KIDSCREEN-27, scores for physical and psychological well-being and social support domain significantly increased from baseline to end-point (p≤0.01). After 6 months of magnesium prophylaxis, disability due to migraine significantly decreased, whereas physical and psychosocial well-being improved. Children also reported fewer anxiety and depressive symptoms. More follow-up and randomized controlled clinical trials are needed to propose clinical recommendations for magnesium prophylaxis in pediatric migraine.

Long-term outcome in children with infantile spasms treated with vigabatrin: a cohort of 180 patients.

OBJECTIVE: Evaluation of efficacy of vigabatrin as the first drug in infants with previously untreated infantile spasms (IS) and reporting the long-term outcome. METHODS: We analyzed a cohort of 180 infants with infantile spasms treated with vigabatrin as the first drug. Following initial evaluation and a 48-h basal period for counting the spasms, vigabatrin was administered using the same protocol in all. After 14 days all infants were assessed for therapeutic response (primary outcome). Psychomotor development was evaluated by a psychologist and neurologist prior to the initiation of treatment and during the follow-up. Seizure outcomes were followed prospectively, by seizure types and epilepsy syndromes. Long-term (secondary) outcomes included neurologic status, occurrence of late epilepsy, and developmental/cognitive status. RESULTS: Vigabatrin terminated the spasms in 101 patients (56.9%) at a mean period of 5 days. Patients with normal psychomotor development prior to the onset of spasms responded best. After follow-up of 2.4 to 18.9 years (mean 10.64; standard deviation [SD] 4.40), 38.1% of responders, treated with vigabatrin, had severe neurologic dysfunction, 42% had epilepsy, and 42.2% had unfavorable intellectual outcome. The group with symptomatic etiology and abnormal neurologic status at presentation demonstrated a significantly worse prognosis and a more unfavorable outcome than cryptogenic or idiopathic cases (85.1% and 81.6% versus 14.9% and 0%-p = 0.001). Idiopathic patients treated with vigabatrin were all intellectually normal, except the youngest patient who had borderline cognitive function. SIGNIFICANCE: The most important prognostic factors were the underlying etiology and preexisting developmental profile. Long-term outcome in the patients treated with vigabatrin was similar to the outcome in patients treated with adrenocorticotropic hormone (ACTH) or corticosteroids, as reported in earlier studies. The long-term prognosis of idiopathic cases treated with vigabatrin was favorable.