Adherence to ketogenic dietary therapies in epilepsy: A systematic review of literature.

Treatment adherence, defined as the degree to which the patient actively follows the plan of care, is very difficult for subjects undergoing ketogenic dietary therapies (KDTs). This is a relevant issue because adherence to dietary therapies is considered 1 of the primary determinants of the treatment's success. This paper aimed to review the literature evidence about KDT adherence according to age and diagnosis of patients. Performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, this systematic review included clinical trials and observational studies. The risk of bias was assessed by the RoB 2.0 Cochrane tool and the quality of evidence according to the Mixed Methods Appraisal Tool system. Twenty-two articles were included, with more than half (n = 12) having average quality (2-3 stars). The studies' heterogeneity in measuring adherence and diagnosis made it difficult to compare results. Mean adherence rates were 71.5%, 66%, and 63.9% for children, adolescents, and adults, respectively. Adherence and compliance rates varied according to the follow-up period (79.7%, 66.7%, and 37.7% at 6, 24, and 36 months, respectively). The most frequent reasons for low adherence were linked to inefficacy in seizure control, adverse effects, food refusal, difficulty in preparing KDT meals or diet restrictiveness, lack of motivation, poor parental compliance, or cost of the diet. To conclude, there is a lack of standardized tools to measure adherence. Several studies highlighted the families' challenges in adhering to KDTs. These factors should be considered when creating strategies and resources on family education.

Cerebellar Heterotopia: Broadening the Neuroradiological Spectrum of KBG Syndrome.

KBG syndrome is a rare genetic disorder caused by heterozygous pathogenic variants in ANKRD11. Affected individuals have developmental delay, short stature, characteristic facial features, and other dysmorphic findings. To date, a spectrum of unspecific neuroradiological defects has been reported in KBG patients, such as cortical defects, white matter abnormalities, corpus callosum, and cerebellar vermis hypoplasia.Deep clinical and neuroradiological phenotyping and genotype of a patient presenting with mild cognitive and behavioral problems were obtained after written informed consent.We herein describe the first KBG patient presenting with cerebellar heterotopia, a heterogeneous malformation characterized by the presence of clusters of neurons within the white matter of cerebellar hemispheres.This novel association broadens the neuroradiological spectrum of KBG syndrome, and further prompts to investigate the potential functions of ANKRD11 in cerebellar development.

Cerebellar heterotopia in an 11-year-old child with KDM6B-related neurodevelopmental disorder: A case report and review of the literature.

Heterozygous pathogenic variants in KDM6B have recently been associated to a rare neurodevelopmental disorder referred to as "Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities" and characterized by non-pathognomonic facial and body dysmorphisms, a wide range of neurodevelopmental and behavioral disorders and nonspecific neuroradiological findings. KDM6B encodes a histone demethylase, expressed in different tissues during development, which regulates gene expression through the modulation of chromatin accessibility by RNA polymerase. We herein describe a 11-year-old male patient carrying a novel de novo pathogenic variant in KDM6B exhibiting facial dysmorphisms, dysgraphia, behavioral traits relatable to oppositional defiant, autism spectrum, and attention deficit hyperactivity disorders, a single seizure episode, and a neuroimaging finding of a single cerebellar heterotopic nodule, never described to date in this genetic condition. These findings expand the phenotypic spectrum of this syndrome, highlighting the potential role for KDM6B in cerebellar development and providing valuable insights for genetic counseling.

The effect of executive function on health related quality of life in children with self-limited epilepsy with centrotemporal spikes.

AIM: The current study aims to investigate the effect of Executive Functions (EFs) on Health Related Quality of Life (HRQoL) in a cohort of children with self-limited epilepsy with centrotemporal spikes (SeLECTS) and to identify possible factors that impact HRQoL specifically related to epilepsy-related variables and EFs skills. MATERIAL AND METHOD: The Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL) and The Behavior Rating Inventory of Executive Function (BRIEF-2 and BRIEF-P) were completed by the parents of 129 patients with SeLECTS. Demographic variables and epilepsy-related variables were collected. RESULTS: Our sample performed in the average range across all the subscales and summary scores of the PedsQL and performed in the normal range of the BRIEF questionnaire. We observed that a lower functioning in EFs was associated with lower overall HRQoL scores. We explored the relationship between epilepsy characteristics and scores on the PedsQL. We found that the use of antiseizure medications (ASMs), longer duration of the treatment, and a higher seizure frequency were associated with a lower HRQoL. Moreover, we observed that executive dysfunction was a significant predictor of reduced HRQoL. CONCLUSION: Our results suggest the importance of the identification of patients with SeLECTS with a high level of risk for a poor HRQoL. We may now add executive dysfunction to the list of known risk factors for poor HRQoL in children with SeLECTS, along with such factors as seizure frequency, recent seizures, use of ASMs and longer duration of therapy. The early identification of children with SeLECTS at risk of a poor HRQoL could allow the activation of adequate interventions.

Blindness affects the developmental trajectory of the sleeping brain.

Sleep plays a crucial role in brain development, sensory information processing, and consolidation. Sleep spindles are markers of these mechanisms as they mirror the activity of the thalamocortical circuits. Spindles can be subdivided into two groups, slow (10-13 Hz) and fast (13-16 Hz), which are each associated with different functions. Specifically, fast spindles oscillate in the high-sigma band and are associated with sensorimotor processing, which is affected by visual deprivation. However, how blindness influences spindle development has not yet been investigated. We recorded nap video-EEG of 50 blind/severely visually impaired (BSI) and 64 sighted children aged 5 months to 6 years old. We considered aspects of both macro- and micro-structural spindles. The BSI children lacked the evolution of developmental spindles within the central area. Specifically, young BSI children presented low central high-sigma and high-beta (25-30 Hz) event-related spectral perturbation and showed no signs of maturational decrease. High-sigma and high-beta activity in the BSI group correlated with clinical indices predicting perceptual and motor disorders. Our findings suggest that fast spindles are pivotal biomarkers for identifying an early developmental deviation in BSI children. These findings are critical for initial therapeutic intervention.

Expanding the phenotype of Brunner syndrome from childhood to adulthood: Description of the second pediatric patient and his mother.

Brunner syndrome is a recessive X-linked disorder caused by pathogenic variants in the monoamine oxidase A gene (MAOA). It is characterized by distinctive aggressive behavior, mild intellectual disability, sleep disturbances, and typical biochemical alterations deriving from the impaired monoamine metabolism. We herein describe a 5-year-old boy with developmental delay, autistic features, and myoclonic epilepsy, and his mother, who had mild intellectual disability and recurrent episodes of palpitations, headache, abdominal pain, and abdominal bloating. Whole exome sequencing allowed detection of the maternally-inherited variant c.410A>G, (p.Glu137Gly) in the MAOA gene. The subsequent biochemical studies confirmed the MAOA deficiency both in the child and his mother. Given the serotonergic symptoms associated with high serotonin levels found in the mother, treatment with a serotonin reuptake inhibitor and dietary modifications were carried out, resulting in regression of the biochemical abnormalities and partial reduction of symptoms. Our report expands the phenotypic spectrum of Brunner disease, bringing new perspectives on the behavioral and neurodevelopmental phenotype from childhood to adulthood.

Sleep effects of Ketogenic diet in pediatric patients with migraine: Preliminary data of a prospective study.

OBJECTIVE/BACKGROUND: Ketogenic dietary therapies' effects on sleep have been poorly investigated up to date. Preliminary results of a prospective study aimed at evaluating possible sleep changes in pediatric patients with migraine treated with classic ketogenic diet are presented. PATIENTS/METHODS: Included patients were aged 14-18 years and had a diagnosis of chronic migraine. A customized classic ketogenic diet was drawn up for all patients and all participants underwent neurological, nutritional and subjective and objective sleep assessment at baseline and after three months of follow-up (standardized sleep questionnaires, polysomnography, actigraphy). RESULTS: The majority of patients reported an improvement in migraine symptoms and quality of life. As far as sleep effects, a possible sleep stabilization was evidenced according to actigraphic data, and polysomnographic data showed a slight increase in total sleep time and sleep efficiency together with a reduction in waking time during night and a trend of NREM stage 1 decrease and REM increase. CONCLUSIONS: Future analyses on a broader population are needed to shed light on the ketogenic dietary therapies' effects on sleep and future research should be devoted to identify influence of possible individual and diet characteristics, and biochemical related changes.

The effects of ketogenic dietary therapies on sleep: A scoping review.

Sleep problems are common in neurological conditions for which ketogenic dietary therapies (KDTs) are recognised as an effective intervention (drug-resistant epilepsy, autism spectrum disorder, and migraine). Given the composite framework of action of ketogenic dietary therapies, the prevalence of sleep disturbance, and the importance of sleep regulation, the present scoping review aimed at identifying and mapping available evidence of the effects of ketogenic dietary therapies on sleep. A comprehensive web-based literature search was performed retrieving publications published to June 2023 using PubMed and Scopus, yielding to 277 records. Twenty papers were finally selected and included in the review. Data were abstracted by independent coders. High variability was identified in study design and sleep outcome evaluation among the selected studies. Several changes in sleep quality and sleep structure under ketogenic dietary therapies were found, namely an improvement of overall sleep quality, improvement in the difficulty falling asleep and nighttime awakenings, improvement in daytime sleepiness and an increase of REM sleep. The relevance and possible physiological explanations of these changes, clinical recommendations, and future directions in the field are discussed.

Validation of an Italian Questionnaire of Adherence to the Ketogenic Dietary Therapies: iKetoCheck.

Ketogenic dietary therapies (KDTs) are an effective and safe non-pharmacological treatment for drug-resistant epilepsy, but adherence can be challenging for both patients and caregivers. In Europe, there are no adequate tools to measure it other than monitoring ketosis. This study aimed to adapt and validate the Brazilian adherence questionnaire, Keto-check, into the Italian version: iKetoCheck. Using the Delphi technique, 12 judges validated the contents through agreement rates and the Content Validity Index (CVI). The iKetocheck was self-completed electronically by 61 drug-resistant epilepsy or GLUT1 deficiency patients within an interval of 15 days to measure its reproducibility. The test-retest reliability was evaluated using Pearson's correlation and relative significance test. Exploratory and confirmatory factorial analyses were made using Factor software version 12.03.02. The final tool, iKetoCheck, consists of 10 questions with 5-point Likert scale answers. It evaluates various aspects such as informing caregivers about the diet, organization of meals, measurement of ketosis, weighing food consumed, diet negligence, use of carbohydrate-free medications, attending follow-up visits, reading food labels, consulting an expert for dietary concerns, and cooking at home. The factorial analysis resulted in three factors: "attention," "organization," and "precision," with satisfactory results for indices in exploratory and confirmatory analyses. Although higher mean values of ketonemia measurement were observed in patients with a higher adherence score, these values were not statistically significant (p = 0.284). In conclusion, despite the small sample size, iKetoCheck is a valid tool for evaluating KDTs' adherence in Italian drug-resistant epilepsy or GLUT1 deficiency patients. It can provide valuable information to improve patient management and optimize the effectiveness of KDTs.

Ketonemia variability through menstrual cycle in patients undergoing classic ketogenic diet.

Introduction: Ketogenic dietary therapies (KDT) are well-established, safe, non-pharmacologic treatments used for children and adults with drug-resistant epilepsy and other neurological disorders. Ketone bodies (KBs) levels are recognized as helpful to check compliance to the KDT and to attempt titration of the diet according to the individualized needs. KBs might undergo inter-individual and intra-individual variability and can be affected by several factors. Possible variations in glycemia and ketone bodies blood levels according to the menstrual cycle have not been systematically assessed yet, but this time window deserves special attention because of hormonal and metabolic related changes. Methods: This study aims at searching for subtle changes in KBs blood level during menstrual cycle in female patients undergoing a stable ketogenic diet, by analyzing 3-months daily measurement of ketone bodies blood levels and glucose blood levels throughout the menstrual cycle. Results: We report the preliminary results on six female patients affected by GLUT1DS or drug resistant epilepsy, undergoing a stable classic ketogenic diet. A significant increase in glucose blood levels during menstruation was found in the entire cohort. As far as the ketone bodies blood levels, an inversely proportional trend compared to glycemia was noted. Conclusion: Exploring whether ketonemia variations might occur according to the menstrual cycle is relevant to determine the feasibility of transient preventive diet adjustments to assure a continuative treatment efficacy and to enhance dietary behavior support. Clinical trial registration: clinicaltrials.gov, identifier NCT05234411.

Electroclinical Improvement in a Patient with Ring Chromosome 20 Syndrome Treated with Zonisamide: A Case Report.

Ring chromosome 20 or r(20) syndrome is a rare chromosomal disorder, mainly characterized by childhood-onset drug-resistant epilepsy with typical electroencephalographic findings, followed by mild to severe cognitive-behavioral decline. Recent studies support a possible role of the dopaminergic system in the epileptogenesis of this syndrome. We report the case of a 13-year-old female with mosaic r(20) who showed typical disease onset and evolution and a remarkable electroclinical improvement with zonisamide. Epilepsy related to r(20) is often medically intractable. When valproate and lamotrigine are not effective, zonisamide could be further investigated as a therapeutic option, since it acts as antifocal and it has a potential role in the prevention of dopamine depletion.

Ketogenic dietary therapies in epilepsy: recommendations of the Italian League against Epilepsy Dietary Therapy Study Group.

A stepwise increase in the utilization of ketogenic dietary therapies for drug-resistant epilepsy has been observed in Italy in the last decade, although it is still considered often underused in many centers when compared to other countries. The Dietary Therapy Study Group of the Italian League against Epilepsy proposes practical recommendations to improve shared knowledge and facilitate the application of ketogenic dietary therapies, optimizing its efficacy and tolerability. The experts involved (11 child neuropsychiatrists, two adult neurologists, one psychologist, one pharmacologist, one pediatric endocrinologist, one representative of patients' associations, and three dietitians and clinical nutritionists) responded to a survey on current clinical practice issues and were asked to discuss controversial topics related to supplementation, long-term maintenance, transition, and a multidisciplinary approach to ketogenic dietary therapies. Practical indications for patient selection, diet initiation, management, side effects prevention, and follow-up are provided.

Ketosis and migraine: a systematic review of the literature and meta-analysis.

Introduction: Headaches are a prevalent disorder worldwide, and there is compelling evidence that certain dietary interventions could provide relief from attacks. One promising approach is ketogenic therapy, which replaces the brain's glucose fuel source with ketone bodies, potentially reducing the frequency or severity of headaches. Aim: This study aims to conduct a systematic review of the scientific literature on the impact of ketosis on migraine, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. Results: After a careful selection process and bias evaluation, 10 articles were included in the review, primarily from Italy. The bias assessment indicated that 50% of the selected articles had a low risk of bias in all domains, with the randomization process being the most problematic domain. Unfortunately, the evaluation of ketosis was inconsistent between articles, with some assessing ketonuria, some assessing ketonemia, and some not assessing ketosis levels at all. Therefore, no association could be made between the level of ketosis and the prevention or reduction of migraine attacks. The ketogenic therapies tested in migraine treatments included the very low-calorie ketogenic diet (VLCKD, n = 4), modified Atkins diet (MAD, n = 3), classic ketogenic diet (cKDT, n = 2), and the administration of an exogenous source of beta-hydroxybutyrate (BHB). The meta-analysis, despite reporting high heterogeneity, found that all interventions had an overall significant effect (Z = 9.07, p < 0.00001; subgroup differences, Chi2 = 9.19, dif = 3, p = 0.03; I2, 67.4%), regardless of the type of endogenous or exogenous induction of ketosis. Conclusion: The initial findings of this study suggest that metabolic ketogenic therapy may provide some benefit in treating migraines and encourage further studies, especially randomized clinical trials with appropriate and standardized methodologies. The review strongly recommends the use of the adequate measurement of ketone levels during ketogenic therapy to monitor adherence to the treatment and improve knowledge of the relationship between ketone bodies and efficacy. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42022330626.

WISC-IV intellectual profiles in Italian children with self-limited epilepsy with centrotemporal spikes.

OBJECTIVE: This study aimed to describe the intellectual profile based on the Wechsler Intelligence Scale for Children 4th edition (WISC-IV) in children with self-limited epilepsy with centrotemporal spikes (SeLECTS), with an attempt to define possible predictive epilepsy-related variables of cognitive performance. METHODS: The WISC-IV was assessed in 161 children with SeLECTS and their cognitive profiles were compared to a matched sample of healthy control children. RESULTS: Children with SeLECTS performed within normal range across all indices, demonstrating particular strength based on the Perceptual Reasoning Index. Compared to healthy control children, we observed a significant difference in performance based on the Full Scale Intelligence Quotient, Verbal Comprehension Index and Processing Speed Index. Regarding epilepsy-related variables, earlier onset of epilepsy, use of anti-seizure medications, the presence of neurodevelopmental disorders, a higher frequency of seizures, and a longer treatment duration were associated with an overall lower level of performance. SIGNIFICANCE: Children with SeLECTS performed within the average range for cognitive assessment based on the WISC-IV, demonstrating that children had normal levels of global intelligence. However, compared to healthy control children, children with SeLECTS showed a slightly lower level of performance. Reasoning skills represented the relative strengths in children with SeLECTS. Predictors of intellectual performance in patients with SeLECTS include epilepsy-related variables and neurodevelopmental comorbidities.

Case report: KETOLAND the psychoeducation program for ketogenic diet.

Glucose transporter type 1 deficiency syndrome (GLUT1DS) is a rare neurological disorder characterized by a wide spectrum of symptoms: epilepsy, movement disorders and neurocognitive impairment. The gold standard treatment for GLUT1DS are ketogenic dietary therapies (KDTs), specifically classical ketogenic diet (CKD). Despite the benefits, CKD often represents a challenge for patients and their families since meal preparation is extremely demanding and deviates a lot from normal diet. To assure an optimal compliance to CKD a psychological support for parents and patients with GLUT1DS is highly recommended. Specifically, a psychoeducational intervention that ameliorates the knowledge about the illness and its therapy improves treatment' s adherence and efficacy. The aim of this case report is to investigate the effectiveness of a psychoeducational program, partially implemented through telepsychology, based on the theoretical model of Cognitive Behavioral Play Therapy (CBPT) to support KDT knowledge and adherence in a patient with GLUT1DS who presented a worsening of her clinical picture due to a sparse knowledge of KDTs principles which determined a low adherence. Thus, with this case report we propose a model of intervention with psychoeducation in a patient with a complex chronic disease.

A Novel De novo Heterozygous Mutation in the SON Gene Associated with Septo-optic Dysplasia: A New Phenotype.

Septo-optic dysplasia (SOD) syndrome is a rare congenital disorder characterized by a classic triad of optic nerve/chiasm hypoplasia, agenesis of septum pellucidum and corpus callosum, and hypoplasia of the hypothalamic-pituitary axis.Herein, we report the clinical case of 2-year-old boy presenting with psychomotor delay, nystagmus, congenital hypothyroidism, and a clinically relevant growth delay. The neuroradiological examination showed partial segmental agenesis of the corpus callosum, agenesis of the septum pellucidum, optic nerve hypoplasia, and a small pituitary gland with a small median pituitary stalk. A whole-exome sequencing analysis detected a novel heterozygous de novo variant c.1069_1070delAG in SON, predicted as likely pathogenic.To date, SON pathogenic variants have been described as responsible for Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome, a multisystemic neurodevelopmental disorder mainly characterized by intellectual disability, facial dysmorphisms, visual abnormalities, brain malformations, feeding difficulties, and growth delay. The herein described case is the first recognized clinic-radiological occurrence of SOD syndrome with hypothalamic-pituitary dysfunction in a patient carrying a SON gene variant, considered responsible of ZTTK syndrome, suggesting a possible relationship between SOD and SON gene alterations, never described so far, making the search for SON gene mutations advisable in patients with SOD.

Melatonin versus Sleep Deprivation for Sleep Induction in Nap Electroencephalography: Protocol for a Prospective Randomized Crossover Trial in Children and Young Adults with Epilepsy.

Electroencephalography (EEG) continues to be a pivotal investigation in children with epilepsy, providing diagnostic evidence and supporting syndromic classification. In the pediatric population, electroencephalographic recordings are frequently performed during sleep, since this procedure reduces the number of artifacts and activates epileptiform abnormalities. To date, no shared guidelines are available for sleep induction in EEG. Among the interventions used in the clinical setting, melatonin and sleep deprivation represent the most used methods. The main purpose of this study is to test the non-inferiority of 3-5 mg melatonin versus sleep deprivation in achieving sleep in nap electroencephalography in children and young adult patients with epilepsy. To test non-inferiority, a randomized crossover trial is proposed where 30 patients will be randomized to receive 3-5 mg melatonin or sleep deprivation. Each enrolled subject will perform EEG recordings during sleep in the early afternoon for a total of 60 EEGs. In the melatonin group, the study drug will be administered a single oral dose 30 min prior to the EEG recording. In the sleep deprivation group, parents will be required to subject the child to sleep deprivation the night before registration. Urinary and salivary concentrations of melatonin and of its main metabolite 6-hydroxymelatonin will be determined by using a validated LC-MS method. The present protocol aims to offer a standardized protocol for sleep induction to be applied to EEG recordings in those of pediatric age. In addition, melatonin metabolism and elimination will be characterized and its potential interference in interictal abnormalities will be assessed.

GLUT1-DS Italian registry: past, present, and future: a useful tool for rare disorders.

BACKGROUND: GLUT1 deficiency syndrome is a rare, genetically determined neurological disorder for which Ketogenic Dietary Treatment represents the gold standard and lifelong treatment. Patient registries are powerful tools providing insights and real-world data on rare diseases. OBJECTIVE: To describe the implementation of a national web-based registry for GLUT1-DS. METHODS: This is a retrospective and prospective, multicenter, observational registry developed in collaboration with the Italian GLUT1-DS association and based on an innovative, flexible and configurable cloud computing technology platform, structured according to the most rigorous requirements for the management of patient's sensitive data. The Glut1 Registry collects baseline and follow-up data on the patient's demographics, history, symptoms, genotype, clinical, and instrumental evaluations and therapies. RESULTS: Five Centers in Italy joined the registry, and two more Centers are currently joining. In the first two years of running, data from 67 patients (40 females and 27 males) have been collected. Age at symptom onset was within the first year of life in most (40, 60%) patients. The diagnosis was formulated in infancy in almost half of the cases (34, 51%). Symptoms at onset were mainly paroxysmal (mostly epileptic seizure and paroxysmal ocular movement disorder) or mixed paroxysmal and fixed symptoms (mostly psychomotor delay). Most patients (53, 79%) are currently under Ketogenic dietary treatments. CONCLUSIONS: We describe the principles behind the design, development, and deployment of the web-based nationwide GLUT1-DS registry. It represents a stepping stone towards a more comprehensive understanding of the disease from onset to adulthood. It also represents a virtuous model from a technical, legal, and organizational point of view, thus representing a possible paradigmatic example for other rare disease registry implementation.

Classic ketogenic diet in parenteral nutrition in a GLUT1DS patient: Doing more with less in an acute surgical setting.

Ketogenic Dietary Treatments (KDTs) are to date the gold-standard treatment for glucose transporter type 1 (GLUT1) deficiency syndrome. Administration of KDTs is generally per os; however, in some conditions including the acute gastro-enteric post-surgical setting, short-term parenteral (PN) administration might be needed. We report the case of a 14-year-old GLUT1DS patient, following classic KDT for many years, who underwent urgent laparoscopic appendectomy. PN-KDT was required, after 1 day of fasting. No ad hoc PN-KDTs products were available and the patient received infusions of OLIMEL N4 (Baxter). On the sixth day postoperatively enteral nutrition was progressively reintroduced. The outcome was optimal with rapid recovery and no exacerbation of neurological manifestations. Our patient is the first pediatric patient with GLUT1DS in chronic treatment with KDT efficiently treated with exclusive PN for five days. This case reports on real-word management and the ideal recommendations for PN-KDT in an acute surgical setting.

A novel variant in NEUROD2 in a patient with Rett-like phenotype points to Glu130 codon as a mutational hotspot.

BACKGROUND: NEUROD2, encoding the neurogenic differentiation factor 2, is essential for neurodevelopment. To date, heterozygous missense variants in this gene have been identified in eight patients (from six unrelated families) with epileptic encephalopathy and developmental delay. CASE REPORT: We describe a child with initial clinical suspicion of Rett/Rett-like syndrome, in whom exome sequencing detected a novel de novo variant (c.388G > A, p.Glu130Lys) in NEUROD2. Interestingly, a missense change affecting the same codon, c.388G > C (p.Glu130Gln), was previously identified in other two patients. CONCLUSIONS: Our results suggest that Glu130 might represent a potential mutational hotspot of NEUROD2. Furthermore, the clinical findings (especially the absence of clinically overt seizures) strengthen the NEUROD2-phenotypic spectrum, implying that developmental delay may also manifest isolatedly. We suggest inclusion of NEUROD2-associated developmental and epileptic encephalopathies (DEEs) in the differential diagnosis of atypical Rett syndrome as well as gene panels related to autism spectrum disorder.