Clinical and functional consequences of GRIA variants in patients with neurological diseases.

AMPA receptors are members of the glutamate receptor family and mediate a fast component of excitatory synaptic transmission at virtually all central synapses. Thus, their functional characteristics are a critical determinant of brain function. We evaluate intolerance of each GRIA gene to genetic variation using 3DMTR and report here the functional consequences of 52 missense variants in GRIA1-4 identified in patients with various neurological disorders.

Mendelian etiologies identified with whole exome sequencing in cerebral palsy.

Objectives: Cerebral palsy (CP) is the most common childhood motor disability, yet its link to single-gene disorders is under-characterized. To explore the genetic landscape of CP, we conducted whole exome sequencing (WES) in a cohort of patients with CP.

Methods: We performed comprehensive phenotyping and WES on a prospective cohort of individuals with cryptogenic CP (who meet criteria for CP; have no risk factors), non-cryptogenic CP (who meet criteria for CP; have at least one risk factor), and CP masqueraders (who could be diagnosed with CP, but have regression/progressive symptoms).

A diagnostic confidence scheme for CLN3 disease.

Over the past 20 years, diagnostic testing for genetic diseases has evolved, leading to variable diagnostic certainty for individuals included in long-term natural history studies. Using genotype and phenotype data from an ongoing natural history study of CLN3 disease, we developed a hierarchical diagnostic confidence scheme with three major classes: Definite, Probable, or Possible CLN3 disease. An additional level, CLN3 Disease PLUS, includes individuals with CLN3 disease plus an additional disorder with a separate etiology that substantially affects the phenotype.

Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.

The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome.

BioVR: a platform for virtual reality assisted biological data integration and visualization.

Background: Functional characterization of single nucleotide variants (SNVs) involves two steps, the first step is to convert DNA to protein and the second step is to visualize protein sequences with their structures. As massively parallel sequencing has emerged as a leading technology in genomics, resulting in a significant increase in data volume, direct visualization of SNVs together with associated protein sequences/structures in a new user interface (UI) would be a more effective way to assess their potential effects on protein function.

Results: We have developed BioVR, an easy-to-use interactive, virtual reality (VR)-assisted platform for integrated visual analysis of DNA/RNA/protein sequences and protein structures using Unity3D and the C# programming language.

Association of Severe Hydrocephalus With Congenital Zika Syndrome.

Importance: Hydrocephalus is a treatable but potentially fatal complication that has not been previously described in congenital Zika syndrome (CZS).

Objective: To describe the clinical features and imaging findings in 24 patients with congenital Zika syndrome (CZS) who developed hydrocephalus.

Design, Setting, And Participants: This case series included patients with hydrocephalus who were born in October and November 2015 and followed up until mid-2017 in the 2 largest national referral centers for CZS in Brazil.

Phenotypes, genotypes, and the management of paroxysmal movement disorders.

Unlabelled: As a consequence of the genomic revolution, a large number of publications describing paroxysmal movement disorders have been published in the last few years, shedding light on their molecular pathology. Routine gene testing is not necessary to guide treatment for typical forms of paroxysmal kinesigenic dyskinesia (PKD), paroxysmal nonkinesigenic dyskinesia (PNKD), and episodic ataxia type 1 or 2. It can, however, be helpful in the management of atypical or complex cases, especially for genetic counselling, treatment strategies, and the offer of preimplantation genetic diagnosis.

Genetic Diagnostics for Neurologists.

Purpose Of Review: This article puts advances in the field of neurogenetics into context and provides a quick review of the broad concepts necessary for current practice in neurology.

Recent Findings: The exponential growth of genetic testing is due to its increased speed and decreasing cost, and it is now a routine part of the clinical care for a number of neurologic patients. In addition, phenotypic pleiotropy (mutations in the same gene causing very disparate phenotypes) and genetic heterogeneity (the same clinical phenotype resulting from mutations in different genes) are now known to exist in a number of conditions, adding an additional layer of complexity for genetic testing in these disorders.

Expanding the neurodevelopmental phenotype of PURA syndrome.

PURA syndrome is a recently described developmental encephalopathy presenting with neonatal hypotonia, feeding difficulties, global developmental delay, severe intellectual disability, and frequent apnea and epilepsy. We describe 18 new individuals with heterozygous sequence variations in PURA. A neuromotor disorder starting with neonatal hyptonia, but ultimately allowing delayed progression to walking, was present in nearly all individuals.

CEDNIK: Phenotypic and Molecular Characterization of an Additional Patient and Review of the Literature.

Synaptosomal-associated protein 29 (SNAP29) is a t-SNARE protein that is implicated in intracellular vesicle fusion. Mutations in the gene have been associated with cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma syndrome (CEDNIK). In patients with 22q11.

India Allele Finder: a web-based annotation tool for identifying common alleles in next-generation sequencing data of Indian origin.

Objective: We built India Allele Finder, an online searchable database and command line tool, that gives researchers access to variant frequencies of Indian Telugu individuals, using publicly available fastq data from the 1000 Genomes Project. Access to appropriate population-based genomic variant annotation can accelerate the interpretation of genomic sequencing data. In particular, exome analysis of individuals of Indian descent will identify population variants not reflected in European exomes, complicating genomic analysis for such individuals.

PLXNA1 developmental encephalopathy with syndromic features: A case report and review of the literature.

Developmental encephalopathies constitute a broad and genetically heterogeneous spectrum of disorders associated with global developmental delay, intellectual disability, frequent epilepsy, and other neurofunctional abnormalities. Here, we report a male presenting with infantile onset epilepsy and syndromic features resembling Dubowitz syndrome identified to have a de novo PLXNA1 variant by whole exome sequencing. This constitutes the second report of PLXNA1 sequence variation associated with early onset epilepsy, and the first to expand on the clinical features of this emerging disorder.

Developing a novel epileptic discharge localization algorithm for electroencephalogram infantile spasms during hypsarrhythmia.

Infantile spasms (ISS) is a devastating epileptic syndrome that affects children under the age of 1 year. The diagnosis of ISS is based on the semiology of the seizure and the electroencephalogram (EEG) background characterized by hypsarrhythmia (HYPS). However, even skilled electrophysiologists may interpret the EEG of children with ISS differently, and commercial software or existing epilepsy detection algorithms are not helpful.

Genetics and genotype-phenotype correlations in early onset epileptic encephalopathy with burst suppression.

Objective: We sought to identify genetic causes of early onset epileptic encephalopathies with burst suppression (Ohtahara syndrome and early myoclonic encephalopathy) and evaluate genotype-phenotype correlations.

Methods: We enrolled 33 patients with a referral diagnosis of Ohtahara syndrome or early myoclonic encephalopathy without malformations of cortical development. We performed detailed phenotypic assessment including seizure presentation, electroencephalography, and magnetic resonance imaging.

Epilepsy-causing sequence variations in SIK1 disrupt synaptic activity response gene expression and affect neuronal morphology.

SIK1 syndrome is a newly described developmental epilepsy disorder caused by heterozygous mutations in the salt-inducible kinase SIK1. To better understand the pathophysiology of SIK1 syndrome, we studied the effects of SIK1 pathogenic sequence variations in human neurons. Primary human fetal cortical neurons were transfected with a lentiviral vector to overexpress wild-type and mutant SIK1 protein.

Neuroimaging findings in Mowat-Wilson syndrome: a study of 54 patients.

Purpose: Mowat-Wilson syndrome (MWS) is a genetic disease characterized by distinctive facial features, moderate to severe intellectual disability, and congenital malformations, including Hirschsprung disease, genital and eye anomalies, and congenital heart defects, caused by haploinsufficiency of the ZEB2 gene. To date, no characteristic pattern of brain dysmorphology in MWS has been defined.

Methods: Through brain magnetic resonance imaging (MRI) analysis, we delineated a neuroimaging phenotype in 54 MWS patients with a proven ZEB2 defect, compared it with the features identified in a thorough review of published cases, and evaluated genotype-phenotype correlations.

Phenotype Differentiation of FOXG1 and MECP2 Disorders: A New Method for Characterization of Developmental Encephalopathies.

Objective: To differentiate developmental encephalopathies by creating a novel quantitative phenotyping tool.

Study Design: We created the Developmental Encephalopathy Inventory (DEI) to differentiate disorders with complex multisystem neurodevelopmental symptoms. We then used the DEI to study the phenotype features of 20 subjects with FOXG1 disorder and 11 subjects with MECP2 disorder.

Automatic localization of epileptic spikes in eegs of children with infantile spasms.

A novel methodology is proposed for identifying epileptiform discharges associated with individuals exhibiting Infantile Spasms (ISS) also known as West Syndrome, which is characterized by electroencephalogram (EEG) recordings exhibiting hypsarrythmia (HYPS). The approach to identify these discharges consists of three stages: first - construct the time-frequency domain (TFD) of the EEG recording using matching pursuit TFD (MP-TFD), second - decompose the TFD matrix into two submatrices (W, H) using non-negative matrix factorization (NMF), and third - use the decomposed spectral and temporal vectors to locate the epileptiform discharges, referred to as spikes, during intervals of HYPS. The method was applied to an EEG dataset of five individuals and the identification of spike locations was compared with those which were visually identified by the epileptologists and those obtained using commercially available clinical analysis software.

Familial recurrences of FOXG1-related disorder: Evidence for mosaicism.

FOXG1-related disorders are caused by heterozygous mutations in FOXG1 and result in a spectrum of neurodevelopmental phenotypes including postnatal microcephaly, intellectual disability with absent speech, epilepsy, chorea, and corpus callosum abnormalities. The recurrence risk for de novo mutations in FOXG1-related disorders is assumed to be low. Here, we describe three unrelated sets of full siblings with mutations in FOXG1 (c.

Autism spectrum disorder and epilepsy: Disorders with a shared biology.

There is an increasing recognition of clinical overlap in patients presenting with epilepsy and autism spectrum disorder (ASD), and a great deal of new information regarding the genetic causes of both disorders is available. Several biological pathways appear to be involved in both disease processes, including gene transcription regulation, cellular growth, synaptic channel function, and maintenance of synaptic structure. We review several genetic disorders where ASD and epilepsy frequently co-occur, and we discuss the screening tools available for practicing neurologists and epileptologists to help determine which patients should be referred for formal ASD diagnostic evaluation.

De novo mutations in SIK1 cause a spectrum of developmental epilepsies.

Developmental epilepsies are age-dependent seizure disorders for which genetic causes have been increasingly identified. Here we report six unrelated individuals with mutations in salt-inducible kinase 1 (SIK1) in a series of 101 persons with early myoclonic encephalopathy, Ohtahara syndrome, and infantile spasms. Individuals with SIK1 mutations had short survival in cases with neonatal epilepsy onset, and an autism plus developmental syndrome after infantile spasms in others.

Characteristic Features of the Interictal EEG Background in 2 Patients With Malignant Migrating Partial Epilepsy in Infancy.

Purpose: To describe chronological electrographic features of the interictal EEG background observed in two patients with malignant migrating partial epilepsy in infancy from neonatal to early infantile period.

Methods: EEGs of two patients who fulfilled diagnostic criteria for malignant migrating partial epilepsy in infancy were acquired over the period of 6 months to monitor treatment efficacy and characterize seizures and other paroxysmal events.

Results: Both patients followed a similar sequential pattern.