Novel Digital Anomalies, Hippocampal Atrophy, and Mutations Expand the Genotypic and Phenotypic Spectra of CNKSR2 in the Houge Type of X-Linked Syndromic Intellectual Development Disorder (MRXSHG).

The Houge type of X-linked syndromic intellectual developmental disorder (MRXSHG) encompasses a spectrum of neurodevelopmental disorders characterized by intellectual disability (ID), language/speech delay, attention issues, and epilepsy. These conditions arise from hemizygous or heterozygous deletions, along with point mutations, affecting CNKSR2, a gene located at Xp22.12.

Clinical and molecular characterization of patients with YWHAG-related epilepsy.

Objective: YWHAG variant alleles have been associated with a rare disease trait whose clinical synopsis includes an early onset epileptic encephalopathy with predominantly myoclonic seizures, developmental delay/intellectual disability, and facial dysmorphisms. Through description of a large cohort, which doubles the number of reported patients, we further delineate the spectrum of YWHAG-related epilepsy.

Methods: We included in this study 24 patients, 21 new and three previously described, with pathogenic/likely pathogenic variants in YWHAG.

Real life retrospective study of cannabidiol therapy in alternating hemiplegia of childhood.

Background: Many alternating hemiplegia of childhood (AHC) patients have received Cannabidiol (CBD) but, to our knowledge, there are no published data available.

Goals: Test the hypothesis that CBD has favorable effects on AHC spells.

Methods: Retrospective review of available data of AHC patients who received CBD.

Exome sequencing of ATP1A3-negative cases of alternating hemiplegia of childhood reveals SCN2A as a novel causative gene.

Alternating hemiplegia of childhood (AHC) is a rare neurodevelopment disorder that is typically characterized by debilitating episodic attacks of hemiplegia, seizures, and intellectual disability. Over 85% of individuals with AHC have a de novo missense variant in ATP1A3 encoding the catalytic α3 subunit of neuronal NaK ATPases. The remainder of the patients are genetically unexplained.

Methodology of a Natural History Study of a Rare Neurodevelopmental Disorder: Alternating Hemiplegia of Childhood as a Prototype Disease.

Here, we describe the process of development of the methodology for an international multicenter natural history study of alternating hemiplegia of childhood as a prototype disease for rare neurodevelopmental disorders. We describe a systematic multistep approach in which we first identified the relevant questions about alternating hemiplegia of childhood natural history and expected challenges. Then, based on our experience with alternating hemiplegia of childhood and on pragmatic literature searches, we identified solutions to determine appropriate methods to address these questions.

Development and testing of methods to record and follow up spells in patients with alternating hemiplegia of childhood.

Background: Developing methods to record Alternating Hemiplegia of Childhood (AHC) spells is essential for clinical trials and patient care.

Objectives: Test the following hypotheses: 1) Video-library training improves participants' ability to correctly identify AHC spells. 2) A custom-designed event-calendar with weekly reviews results in consistent documentation of such events over time.

Sex-based electroclinical differences and prognostic factors in epilepsy with eyelid myoclonia.

Although a striking female preponderance has been consistently reported in epilepsy with eyelid myoclonia (EEM), no study has specifically explored the variability of clinical presentation according to sex in this syndrome. Here, we aimed to investigate sex-specific electroclinical differences and prognostic determinants in EEM. Data from 267 EEM patients were retrospectively analyzed by the EEM Study Group, and a dedicated multivariable logistic regression analysis was developed separately for each sex.

The spectrum of epilepsy with eyelid myoclonia: delineation of disease subtypes from a large multicenter study.

Objective: Epilepsy with eyelid myoclonia (EEM) has been associated with marked clinical heterogeneity. Early epilepsy onset has been recently linked to lower chances of achieving sustained remission and to a less favorable neuropsychiatric outcome. However, much work is still needed to better delineate this epilepsy syndrome.

The gain of function SCN1A disorder spectrum: novel epilepsy phenotypes and therapeutic implications.

Brain voltage-gated sodium channel NaV1.1 (SCN1A) loss-of-function variants cause the severe epilepsy Dravet syndrome, as well as milder phenotypes associated with genetic epilepsy with febrile seizures plus. Gain of function SCN1A variants are associated with familial hemiplegic migraine type 3.

Electroclinical Features and Long-term Seizure Outcome in Patients With Eyelid Myoclonia With Absences.

Background And Objectives: Eyelid myoclonia (EM) with absences (EMA) is a generalized epilepsy syndrome with a prognosis and clinical characteristics that are still partially undefined. We investigated electroclinical endophenotypes and long-term seizure outcome in a large cohort of patients with EMA.

Methods: In this multicenter retrospective study, patients with EMA with ≥5 years of follow-up were included.

Neural correlates of verbal working memory in children with epilepsy with centro-temporal spikes.

Background: Previous functional magnetic resonance imaging (fMRI) studies have identified brain systems underlying different components of working memory (WM) in healthy subjects. The aim of this study was to compare the functional integrity of these neural networks in children with self-limited childhood epilepsy with centro-temporal spikes (ECTS) as compared to healthy controls, using a verbal working memory task (WMT).

Methods: Functional MRI of WM in seventeen 6-to-13 year-old children, diagnosed with ECTS, and 17 sex- and age-matched healthy controls were conducted at 3 T.

Cardiac phenotype in -related syndromes: A multicenter cohort study.

Objective: To define the risks and consequences of cardiac abnormalities in -related syndromes.

Methods: Patients meeting clinical diagnostic criteria for rapid-onset dystonia-parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) with genetic analysis and at least 1 cardiac assessment were included. We evaluated the cardiac phenotype in an knock-in mouse (Mashl) to determine the sequence of events in seizure-related cardiac death.

Movement disorders in patients with alternating hemiplegia: "Soft" and "stiff" at the same time.

Objective: To assess nonparoxysmal movement disorders in mutation-positive patients with alternating hemiplegia of childhood (AHC).

Methods: Twenty-eight patients underwent neurologic examination with particular focus on movement phenomenology by a specialist in movement disorders. Video recordings were reviewed by another movement disorders specialist and data were correlated with patients' characteristics.

Predictive factors and prognostic value for status epilepticus in newborns.

Objectives: To evaluate the predictive factors for status epilepticus (SE) in neonates and prognostic factors for patient outcomes in newborns suffering either isolated seizures or SE.

Methods: A retrospective single-center study from January 2010 to December 2014, included 91 newborns who had neonatal seizures. Among them, 50 newborns experienced SE and 41 newborns presented isolated seizures only.