GRIN2A: an aptly named gene for speech dysfunction

Solving the Etiology of Developmental and Epileptic Encephalopathy with Spike-Wave Activation in Sleep (D/EE-SWAS)

OBJECTIVE

To understand the etiological landscape and phenotypic differences between 2 developmental and epileptic encephalopathy (DEE) syndromes: DEE with spike-wave activation in sleep (DEE-SWAS) and epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS).

METHODS

All patients fulfilled International League Against Epilepsy (ILAE) DEE-SWAS or EE-SWAS criteria with a Core cohort (n = 91) drawn from our Epilepsy Genetics research program, together with 10 etiologically solved patients referred by collaborators in the Expanded cohort (n = 101). Detailed phenotyping and analysis of molecular genetic results were performed. We compared the phenotypic features of individuals with DEE-SWAS and EE-SWAS. Brain-specific gene co-expression analysis was performed for D/EE-SWAS genes.

RESULTS

We identified the etiology in 42/91 (46%) patients in our Core cohort, including 29/44 (66%) with DEE-SWAS and 13/47 (28%) with EE-SWAS. A genetic etiology was identified in 31/91 (34%). D/EE-SWAS genes were highly co-expressed in brain, highlighting the importance of channelopathies and transcriptional regulators. Structural etiologies were found in 12/91 (13%) individuals. We identified 10 novel D/EE-SWAS genes with a range of functions: ATP1A2, CACNA1A, FOXP1, GRIN1, KCNMA1, KCNQ3, PPFIA3, PUF60, SETD1B, and ZBTB18, and 2 novel copy number variants, 17p11.2 duplication and 5q22 deletion. Although developmental regression patterns were similar in both syndromes, DEE-SWAS was associated with a longer duration of epilepsy and poorer intellectual outcome than EE-SWAS.

INTERPRETATION

DEE-SWAS and EE-SWAS have highly heterogeneous genetic and structural etiologies. Phenotypic analysis highlights valuable clinical differences between DEE-SWAS and EE-SWAS which inform clinical care and prognostic counseling. Our etiological findings pave the way for the development of precision therapies. ANN NEUROL 2024;96:932-943.

L-serine treatment in patients with GRIN-related encephalopathy: a phase 2A, non-randomized study

GRIN-related disorders are rare developmental encephalopathies with variable manifestations and limited therapeutic options. Here, we present the first non-randomized, open-label, single-arm trial (NCT04646447) designed to evaluate the tolerability and efficacy of L-serine in children with GRIN genetic variants leading to loss-of-function. In this phase 2A trial, patients aged 2-18 years with GRIN loss-of-function pathogenic variants received L-serine for 52 weeks. Primary end points included safety and efficacy by measuring changes in the Vineland Adaptive Behavior Scales, Bayley Scales, age-appropriate Wechsler Scales, Gross Motor Function-88, Sleep Disturbance Scale for Children, Pediatric Quality of Life Inventory, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months of treatment. Secondary outcomes included seizure frequency and intensity reduction and EEG improvement. Assessments were performed 3 months and 1 day before starting treatment and 1, 3, 6 and 12 months after beginning the supplement. Twenty-four participants were enrolled (13 males/11 females, mean age 9.8 years, SD 4.8), 23 of whom completed the study. Patients had GRIN2B, GRIN1 and GRIN2A variants (12, 6 and 5 cases, respectively). Their clinical phenotypes showed 91% had intellectual disability (61% severe), 83% had behavioural problems, 78% had movement disorders and 58% had epilepsy. Based on the Vineland Adaptive Behavior Composite standard scores, nine children were classified as mildly impaired (cut-off score > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in the Daily Living Skills domain (P = 0035) from the Vineland Scales within the mild group. Expressive (P = 0.005), Personal (P = 0.003), Community (P = 0.009), Interpersonal (P = 0.005) and Fine Motor (P = 0.031) subdomains improved for the whole cohort, although improvement was mostly found in the mild group. The Growth Scale Values in the Cognitive subdomain of the Bayley-III Scale showed a significant improvement in the severe group (P = 0.016), with a mean increase of 21.6 points. L-serine treatment was associated with significant improvement in the median Gross Motor Function-88 total score (P = 0.002) and the mean Pediatric Quality of Life total score (P = 0.00068), regardless of severity. L-serine normalized the EEG pattern in five children and the frequency of seizures in one clinically affected child. One patient discontinued treatment due to irritability and insomnia. The trial provides evidence that L-serine is a safe treatment for children with GRIN loss-of-function variants, having the potential to improve adaptive behaviour, motor function and quality of life, with a better response to the treatment in mild phenotypes.

Genetic architecture of childhood speech disorder: a review

Severe speech disorders lead to poor literacy, reduced academic attainment and negative psychosocial outcomes. As early as the 1950s, the familial nature of speech disorders was recognized, implying a genetic basis; but the molecular genetic basis remained unknown. In 2001, investigation of a large three generational family with severe speech disorder, known as childhood apraxia of speech (CAS), revealed the first causative gene; FOXP2. A long hiatus then followed for CAS candidate genes, but in the past three years, genetic analysis of cohorts ascertained for CAS have revealed over 30 causative genes. A total of 36 pathogenic variants have been identified from 122 cases across 3 cohorts in this nascent field. All genes identified have been in coding regions to date, with no apparent benefit at this stage for WGS over WES in identifying monogenic conditions associated with CAS. Hence current findings suggest a remarkable one in three children have a genetic variant that explains their CAS, with significant genetic heterogeneity emerging. Around half of the candidate genes identified are currently supported by medium (6 genes) to strong (9 genes) evidence supporting the association between the gene and CAS. Despite genetic heterogeneity; many implicated proteins functionally converge on pathways involved in chromatin modification or transcriptional regulation, opening the door to precision diagnosis and therapies. Most of the new candidate genes for CAS are associated with previously described neurodevelopmental conditions that include intellectual disability, autism and epilepsy; broadening the phenotypic spectrum to a distinctly milder presentation defined by primary speech disorder in the setting of normal intellect. Insights into the genetic bases of CAS, a severe, rare speech disorder, are yet to translate to understanding the heritability of more common, typically milder forms of speech or language impairment such as stuttering or phonological disorder. These disorders likely follow complex inheritance with polygenic contributions in many cases, rather than the monogenic patterns that underly one-third of patients with CAS. Clinical genetic testing for should now be implemented for individuals with CAS, given its high diagnostic rate, which parallels many other neurodevelopmental disorders where this testing is already standard of care. The shared mechanisms implicated by gene discovery for CAS highlight potential new targets for future precision therapies.

Epilepsies

Recent advances in genetic diagnosis have revealed the underlying etiology of many epilepsies and have identified pathogenic, causative variants in numerous ion and ligand-gated channel genes. This chapter describes the clinical presentations of epilepsy associated with different channelopathies including classic electroclinical syndromes and emerging gene-specific phenotypes. Also discussed are the archetypal epilepsy channelopathy, SCN1A-Dravet syndrome, considering the expanding phenotype. Clinical presentations where a channelopathy is suspected, such as sleep-related hypermotor epilepsy and epilepsy in association with movement disorders, are reviewed. Channelopathies pose an intriguing problem for the development of gene therapies. Design of targeted therapies requires physiologic insights into the often multifaceted impact of a pathogenic variant, coupled with an understanding of the phenotypic spectrum of a gene. As gene-specific novel therapies come online for the channelopathies, it is essential that clinicians are able to recognize epilepsy phenotypes likely to be due to channelopathy and institute early genetic testing in both children and adults. These findings are likely to have immediate management implications and to inform prognostic and reproductive counseling.

GRIN2A-related epilepsy and speech disorders: A comprehensive overview with a focus on the role of precision therapeutics

Language dysfunction is a common and serious comorbidity of epilepsy, especially in individuals with epilepsy aphasia spectrum syndromes. Childhood epilepsy with centrotemporal spikes is on the mild end of the spectrum, while epileptic encephalopathy with continuous spike-and-wave during sleep syndrome is on the severe end. Traditional antiseizure medicines and immunotherapy are currently used to treat severely affected patients, but the results are usually disappointing. The discovery that GRIN2A is the primary monogenic etiology of these diseases has opened the door to precision treatments. The GRIN2A gene encodes GluN2A protein, which constitutes a subunit of the NMDA receptor (NMDAR). The GRIN2A pathogenic variants cause gain or loss of function of NMDAR; the former can be treated with uncompetitive NMDAR antagonists, such as memantine, while the latter with NMDAR co-agonist serine. Hyper-precision therapies with various other effective agents are likely to be developed shortly to target the diverse functional effects of different variants. Precision treatments for GRIN2A-related disorders will benefit those who suffer from the condition and pave the way for new therapeutic approaches to a variety of other NMDAR-linked neurodegenerative and psychiatric diseases (schizophrenia, Parkinson's disease, Alzheimer's disease, and so on). Furthermore, more research into GRIN2A-related disorders will help us better understand the neuroinflammatory and neuroimmunological basis of epilepsy, as well as the pathological and physiological network activation mechanisms that cause sleep activation of central-temporal spikes and language impairment.

Delving into the Genetic Causes of Language Impairment in a Case of Partial Deletion of NRXN1

Introduction

Copy-number variations (CNVs) impacting on small DNA stretches and associated with language deficits provide a unique window to the role played by specific genes in language function.

Methods

We report in detail on the cognitive, language, and genetic features of a girl bearing a small deletion (0.186 Mb) in the 2p16.3 region, arr[hg19] 2p16.3(50761778_50947729)×1, affecting exons 3-7 of NRXN1, a neurexin-coding gene previously related to schizophrenia, autism (ASD), attention deficit hyperactivity disorder (ADHD), mood disorder, and intellectual disability (ID).

Results

The proband exhibits many of the features commonly found in subjects with deletions of NRXN1, like ASD-like traits (including ritualized behaviors, disordered sensory aspects, social disturbances, and impaired theory of mind), ADHD symptoms, moderate ID, and impaired speech and language. Regarding this latter aspect, we observed altered speech production, underdeveloped phonological awareness, minimal syntax, serious shortage of active vocabulary, impaired receptive language, and inappropriate pragmatic behavior (including lack of metapragmatic awareness and communicative use of gaze). Microarray analyses point to the dysregulation of several genes important for language function in the girl compared to her healthy parents.

Discussion

Although some basic cognitive deficit - such as the impairment of executive function - might contribute to the language problems exhibited by the proband, molecular evidence suggests that they might result, to a great extent, from the abnormal expression of genes directly related to language.

Clinical Spectrum and Treatment Outcomes of Patients with Developmental and/or Epileptic Encephalopathy with Spike-and-Wave Activation in Sleep

Purpose: Developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep (D/EE-SWAS) is a spectrum of conditions characterized by various phenotypes of cognitive, linguistic, and behavioral regression associated with spike-and-wave activation in sleep. We aimed to investigate the phenotypic spectrum and treatment outcomes of pediatric patients with D/EE-SWAS.Methods: We retrospectively analyzed the medical records of pediatric patients diagnosed with D/EE-SWAS and treated at Severance Children’s Hospital from 2006 to 2022. We extracted information from their medical records on electroencephalography before and after treatment, types of treatment, seizure frequency, and developmental profiles. The primary outcome was reduction of the spike-wave index on electroencephalography after treatment.Results: Twenty-one patients with a median age of 5.3 years (interquartile range, 4.1 to 6.6) at diagnosis were included. Ten patients had delayed development. The patients received various anti-seizure medications. Fourteen received long-term, high-dose steroid therapy, 10 were placed on a ketogenic diet, four received intravenous steroid pulse therapy, and one each was treated with intravenous immunoglobulin and cannabidiol. The most effective treatments were steroid therapy and a ketogenic diet, which were also effective in reducing seizures and improving cognition. Side effects during treatment were transient and treatable.Conclusion: We described the clinical spectrum of pediatric patients with D/EE-SWAS. Steroid therapy and a ketogenic diet can be considered effective therapeutic options for patients with D/EE SWAS.

Genetic aetiologies for childhood speech disorder: novel pathways co-expressed during brain development

Childhood apraxia of speech (CAS), the prototypic severe childhood speech disorder, is characterized by motor programming and planning deficits. Genetic factors make substantive contributions to CAS aetiology, with a monogenic pathogenic variant identified in a third of cases, implicating around 20 single genes to date. Here we aimed to identify molecular causation in 70 unrelated probands ascertained with CAS. We performed trio genome sequencing. Our bioinformatic analysis examined single nucleotide, indel, copy number, structural and short tandem repeat variants. We prioritised appropriate variants arising de novo or inherited that were expected to be damaging based on in silico predictions. We identified high confidence variants in 18/70 (26%) probands, almost doubling the current number of candidate genes for CAS. Three of the 18 variants affected SETBP1, SETD1A and DDX3X, thus confirming their roles in CAS, while the remaining 15 occurred in genes not previously associated with this disorder. Fifteen variants arose de novo and three were inherited. We provide further novel insights into the biology of child speech disorder, highlighting the roles of chromatin organization and gene regulation in CAS, and confirm that genes involved in CAS are co-expressed during brain development. Our findings confirm a diagnostic yield comparable to, or even higher, than other neurodevelopmental disorders with substantial de novo variant burden. Data also support the increasingly recognised overlaps between genes conferring risk for a range of neurodevelopmental disorders. Understanding the aetiological basis of CAS is critical to end the diagnostic odyssey and ensure affected individuals are poised for precision medicine trials.

Myoclonus-Dystonia in an Individual with a Mutation in the GRIN2A Gene

Mutations in the GRIN2A gene are associated with epilepsy-aphasia spectrum disorders and developmental and epileptic encephalopathies. Associations have been linked with disorders, including autism spectrum disorder and Parkinson's disease. Recently, GRIN2A variants have been reported as a cause of movement disorders in individuals without epilepsy, suggesting that movement disorders should be highlighted as a genetic phenotype associated with pathogenic variants in GRIN2A. We present a case of a male with myoclonus dystonia and without epilepsy found on whole-exome sequencing to have a c.1880G > A; p.S627N variant in the GRIN2A gene. Our case contributes to the expanding phenotypic spectrum of GRIN2A-related disorders and highlights another genetic cause of the myoclonus-dystonia phenotype. GRIN2A should be considered a part of the differential diagnosis of myoclonus-dystonia in individuals with developmental delay without epilepsy.

The importance of deep speech phenotyping for neurodevelopmental and genetic disorders: a conceptual review

BACKGROUND

Speech is the most common modality through which language is communicated, and delayed, disordered, or absent speech production is a hallmark of many neurodevelopmental and genetic disorders. Yet, speech is not often carefully phenotyped in neurodevelopmental disorders. In this paper, we argue that such deep phenotyping, defined as phenotyping that is specific to speech production and not conflated with language or cognitive ability, is vital if we are to understand how genetic variations affect the brain regions that are associated with spoken language. Speech is distinct from language, though the two are related behaviorally and share neural substrates. We present a brief taxonomy of developmental speech production disorders, with particular emphasis on the motor speech disorders childhood apraxia of speech (a disorder of motor planning) and childhood dysarthria (a set of disorders of motor execution). We review the history of discoveries concerning the KE family, in whom a hereditary form of communication impairment was identified as childhood apraxia of speech and linked to dysfunction in the FOXP2 gene. The story demonstrates how instrumental deep phenotyping of speech production was in this seminal discovery in the genetics of speech and language. There is considerable overlap between the neural substrates associated with speech production and with FOXP2 expression, suggesting that further genes associated with speech dysfunction will also be expressed in similar brain regions. We then show how a biologically accurate computational model of speech production, in combination with detailed information about speech production in children with developmental disorders, can generate testable hypotheses about the nature, genetics, and neurology of speech disorders.

CONCLUSIONS

Though speech and language are distinct, specific types of developmental speech disorder are associated with far-reaching effects on verbal communication in children with neurodevelopmental disorders. Therefore, detailed speech phenotyping, in collaboration with experts on pediatric speech development and disorders, can lead us to a new generation of discoveries about how speech development is affected in genetic disorders.

International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions

The 2017 International League Against Epilepsy classification has defined a three-tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self-limited focal epilepsies, comprising four syndromes: self-limited epilepsy with centrotemporal spikes, self-limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic-atonic seizures, Lennox-Gastaut syndrome, developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep, hemiconvulsion-hemiplegia-epilepsy syndrome, and febrile infection-related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.

The Genetic and Molecular Basis of Developmental Language Disorder: A Review

Language disorders are highly heritable and are influenced by complex interactions between genetic and environmental factors. Despite more than twenty years of research, we still lack critical understanding of the biological underpinnings of language. This review provides an overview of the genetic landscape of developmental language disorders (DLD), with an emphasis on the importance of defining the specific features (the phenotype) of DLD to inform gene discovery. We review the specific phenotype of DLD in the genetic literature, and the influence of historic variation in diagnostic inclusion criteria on researchers' ability to compare and replicate genotype-phenotype studies. This review provides an overview of the recently identified gene pathways in populations with DLD and explores current state-of-the-art approaches to genetic analysis based on the hypothesised architecture of DLD. We will show how recent global efforts to unify diagnostic criteria have vastly increased sample size and allow for large multi-cohort metanalyses, leading the identification of a growing number of contributory loci. We emphasise the important role of estimating the genetic architecture of DLD to decipher underlying genetic associations. Finally, we explore the potential for epigenetics and environmental interactions to further unravel the biological basis of language disorders.

Neurodevelopmental Disorders Associated with PSD-95 and Its Interaction Partners

The postsynaptic density (PSD) is a massive protein complex, critical for synaptic strength and plasticity in excitatory neurons. Here, the scaffolding protein PSD-95 plays a crucial role as it organizes key PSD components essential for synaptic signaling, development, and survival. Recently, variants in DLG4 encoding PSD-95 were found to cause a neurodevelopmental disorder with a variety of clinical features including intellectual disability, developmental delay, and epilepsy. Genetic variants in several of the interaction partners of PSD-95 are associated with similar phenotypes, suggesting that deficient PSD-95 may affect the interaction partners, explaining the overlapping symptoms. Here, we review the transmembrane interaction partners of PSD-95 and their association with neurodevelopmental disorders. We assess how the structural changes induced by DLG4 missense variants may disrupt or alter such protein-protein interactions, and we argue that the pathological effect of DLG4 variants is, at least partly, exerted indirectly through interaction partners of PSD-95. This review presents a direction for functional studies to elucidate the pathogenic mechanism of deficient PSD-95, providing clues for therapeutic strategies.

Clinical and therapeutic significance of genetic variation in the GRIN gene family encoding NMDARs

Considerable genetic variation of N-methyl-d-aspartate receptors (NMDARs) has recently become apparent, with many hundreds of de novo variants identified through widely available clinical genetic testing. Individuals with GRIN variants present with neurological conditions such as epilepsy, autism, intellectual disability (ID), movement disorders, schizophrenia and behavioral disorders. Determination of the functional consequence of genetic variation for NMDARs should lead to precision therapeutics. Furthermore, genetic animal models harboring human variants have the potential to reveal mechanisms that are shared among different neurological conditions, providing strategies that may allow treatment of individuals who are refractory to therapy. Preclinical studies in animal models and small open label trials in humans support this idea. However, additional functional data for variants and animal models corresponding to multiple individuals with the same genotype are needed to validate this approach and to lead to thoughtfully designed, randomized, placebo-controlled clinical trials, which could provide data in order to determine safety and efficacy of potential precision therapeutics.

Maximum repetition rate in a large cross-sectional sample of typically developing Dutch-speaking children

Purpose: The current study aims to provide normative data for the maximum repetition rate (MRR) development of Dutch-speaking children based on a large cross-sectional study using a standardised protocol.Method: A group of 1014 typically developing children aged 3;0 to 6;11 years performed the MRR task of the Computer Articulation Instrument (CAI). The number of syllables per second was calculated for mono-, bi-, and trisyllabic sequences (MRR-pa, MRR-ta, MRR-ka, MRR-pata, MRR-taka, MRR-pataka). A two-way mixed ANOVA was conducted to compare the effects of age and gender on MRR scores in different MRR sequences.Result: The data analysis showed that overall MRR scores were affected by age group, gender and MRR sequence. For all MRR sequences the MRR increased significantly with age. MRR-pa was the fastest sequence, followed by respectively MRR-ta, MRR-pata, MRR-taka, MRR-ka and MRR-pataka. Overall MRR scores were higher for boys than for girls, for all MRR sequences.Conclusion: This study presents normative data of MRR of Dutch-speaking children aged 3;0 to 6;11 years. These norms might be useful in clinical practice to differentiate children with speech sound disorders from typically developing children. More research on this topic is necessary. It is also suggested to collect normative data for other individual languages, using the same protocol.

Language impairment with a microduplication in 1q42.3q43

Deletions and duplications of the distal region of the long arm of chromosome 1 are associated with brain abnormalities and developmental delay. Because duplications are less frequent than deletions, no detailed account of the cognitive profile of the affected people is available, particularly, regarding their language (dis)abilities. In this paper we report on the cognitive and language capacities of a girl with one of the smallest interstitial duplications ever described in this region, affecting to 1q42.3q43 (arr[hg19] 1q42.3q43(235,963,632-236,972,276)x3), and advance potential candidate genes for the observed deficits. The proband's speech is severely impaired, exhibiting dysarthric-like features, with speech problems also resulting from a phonological deficit boiling down to a verbal auditory memory deficit. Lexical and grammatical knowledge are also impaired, impacting negatively on both expressive and receptive abilities, seemingly as a consequence of the phonological deficit. Still, her pragmatic abilities seem to be significantly spared, granting her a good command on the principles governing conversational exchanges. Genetic analyses point to several genes of interest. These include one gene within the duplicated region (LYST), one predicted functional partner (CMIP), and three genes outside the 1q42.3q43 region, which are all highly expressed in the cerebellum: DDIT4 and SLC29A1, found strongly downregulated in the proband compared to her healthy parents, and CNTNAP3, found strongly upregulated. The genes highlighted in the paper emerge as potential candidates for the phonological and speech deficits exhibited by the proband and ultimately, for her problems with language.

GRIN2A and GRIN2B and Their Related Phenotypes

Glutamate is the most relevant excitatory neurotransmitter of the central nervous system; it binds with several receptors, including N-methyl-D-aspartate receptors (NMDARs), a subtype of ionotropic glutamate receptor that displays voltage-dependent block by Mg2+ and a high permeability to Ca2+. GRIN2A and GRIN2B genes encode the GluN2A and GluN2B subunits of the NMDARs, which play important roles in synaptogenesis, synaptic transmission, and synaptic plasticity, as well as contributing to neuronal loss and dysfunction in several neurological disorders. Recently, individuals with a range of childhood-onset drug-resistant epilepsies, such as Landau–Kleffner or Lennox–Gastaut syndrome, intellectual disability (ID), and other neurodevelopmental abnormalities have been found to carry mutations in GRIN2A and GRIN2B, with high variable expressivity in phenotype. The first one is found mainly in epilepsy-aphasia syndromes, while the second one mainly in autism, schizophrenia, and ID, such as autism spectrum disorders. Brain magnetic resonance imaging alterations are found in some patients, even if without a clear clinical correlation. At the same time, increasing data on genotype–phenotype correlation have been found, but this is still not fully demonstrated. There are no specific therapies for the treatment of correlated NMDARs epilepsy, although some evidence with memantine, an antagonist of glutamate receptor, is reported in the literature in selected cases with mutation determining a gain of function.

Feature-driven classification reveals potential comorbid subtypes within childhood apraxia of speech

Background

Childhood apraxia of speech (CAS) is a neurodevelopmental disorder with heterogeneous communication and other comorbid manifestations. While previous studies have characterized speech deficits associated with CAS, few studies have examined variability in reading and language and/or other developmental comorbidities. We sought to identify comorbid subgroups within CAS that could be clinically relevant as well as genetically distinctive.

Methods

In a group of 31 children with CAS and 8 controls, we performed hierarchical cluster analysis utilizing measures of articulation, vocabulary, and reading. We also conducted a chart review of the children with CAS to examine other clinical characteristics in these children and their association with subgroup membership.

Results

We identified 3 comorbid subgroups within CAS of varying severity. The high severity subgroup was characterized by poor reading and vocabulary, and the moderate severity subgroup by poor reading and non-word repetition but average vocabulary, compared to the mild severity subgroup. Subgroups were indistinguishable with respect to speech sound production, the hallmark of CAS, all demonstrating poor articulation. Children in the most severe subgroup were more likely to have early problems feeding (p = 0.036).

Conclusions

Children with CAS may potentially be classified into comorbidity groups based on performance on vocabulary and reading measures, providing additional insight into the heterogeneity within CAS with implications for educational interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-020-02421-1.

A genetic window to auditory-verbal problems in bipolar disorder

Bipolar disorder is a high prevalent psychiatric condition entailing recurrent episodes of elevated mood and depression, but also diverse cognitive problems. One deficit observed in patients concerns to auditory-verbal processing. Being a hereditary condition with a complex genetic architecture, it is not clear which genes contribute to this deficit. We show that candidates for bipolar disorder significantly overlap with candidates for clinical conditions resulting from a deficit in the phonological loop of working memory, particularly, developmental dyslexia and specific language impairment. The overlapping genes are involved in aspects of brain development and function (particularly, brain oscillations) potentially underlying phonological processing and accordingly, emerge as promising candidates for auditory-verbal deficits in bipolar disorder.

The Utility of Speech-Language Biomarkers to Predict Oral Feeding Outcomes in the Premature Newborn

Purpose Successful oral feeding and speech emergence are dependent upon the coordination of shared oral muscles and facial nerves. We aimed to determine if the speech-associated genes, forkhead box P2 (FOXP2), contactin-associated protein-like 2 (CNTNAP2), glutamate receptor, ionotropic, N-methyl D-aspartate 2A (GRIN2A), and neurexin 1, were detectable in neonatal saliva and could predict feeding outcomes in premature newborns. Method In this prospective, observational, preliminary study, saliva collected from 51 premature infants (gestational ages: 30-34 6/7 weeks) at different stages of oral feeding development underwent gene expression analysis. Binary (+/-) expression profiles were explored and examined in relation to days to achieve full oral feeds. Results GRIN2A and neurexin 1 rarely amplified in neonatal saliva and were not informative. Infants who amplified FOXP2 but not CNTNAP2 at the start of oral feeds achieved oral feeding success 3.20 (95% CI [-2.5, 8.9]) days sooner than other gene combinations. Conclusions FOXP2 and CNTNAP2 may be informative in predicting oral feeding outcomes in newborns. Salivary analysis at the start of oral feeding trials may inform feeding outcomes in this population and warrants further investigation.

Genetic pathways involved in human speech disorders

Rare genetic variants that disrupt speech development provide entry points for deciphering the neurobiological foundations of key human capacities. The value of this approach is illustrated by FOXP2, a transcription factor gene that was implicated in speech apraxia, and subsequently investigated using human cell-based systems and animal models. Advances in next-generation sequencing, coupled to de novo paradigms, facilitated discovery of etiological variants in additional genes in speech disorder cohorts. As for other neurodevelopmental syndromes, gene-driven studies show blurring of boundaries between diagnostic categories, with some risk genes shared across speech disorders, intellectual disability and autism. Convergent evidence hints at involvement of regulatory genes co-expressed in early human brain development, suggesting that etiological pathways could be amenable for investigation in emerging neural models such as cerebral organoids.

Expanding the clinical and EEG spectrum of CNKSR2-related encephalopathy with status epilepticus during slow sleep (ESES)

OBJECTIVE

To investigate the clinical and EEG features of Encephalopathy with Status Epilepticus during slow Sleep (ESES) related to CNKSR2 pathogenic variants.

METHODS

Detailed clinical history, repeated wakefulness/overnight sleep EEGs, brain MRI were collected in five patients, including one female, with CNKSR2-related ESES.

RESULTS

Neurodevelopment in infancy was normal in two patients, delayed in three. Epilepsy onset (age range: 2-6 years) was associated with appearance or aggravation of cognitive impairment, language regression and/or behavioral disorders. Worsening of epilepsy and of cognitive/behavioral disturbances paralleled by enhancement of non-rapid eye movement (NREM) sleep-related, frontally predominant, EEG epileptic discharges [spike-wave-index (SWI): range 60-96%] was consistent with ESES. In three patients, episodes of absence status epilepticus or aggravation of atypical absences occurred, in this latter case associated with striking increment of awake SWI. Speech/oro-motor dyspraxia was diagnosed in four patients. In two patients, long-term follow-up showed epilepsy remission and persistence of mild/moderate cognitive disorders and behavioral disturbances into adulthood.

CONCLUSIONS

Novel findings of our study are occurrence also in females, normal neurodevelopment before epilepsy onset, epilepsy aggravation associated with enhanced awake SWI, mild/moderate evolution in adulthood and language disorder due to speech/oro-motor dyspraxia.

SIGNIFICANCE

Our findings expand the phenotypic spectrum of CNKSR2-related ESES.

Ion Channel Functions in Early Brain Development

During prenatal brain development, ion channels are ubiquitous across several cell types, including progenitor cells and migrating neurons but their function has not been clear. In the past, ion channel dysfunction has been primarily studied in the context of postnatal, differentiated neurons that fire action potentials - notably ion channels mutated in the epilepsies - yet data now support a surprising role in prenatal human brain disorders as well. Modern gene discovery approaches have identified defective ion channels in individuals with cerebral cortex malformations, which reflect abnormalities in early-to-middle stages of embryonic development (prior to ubiquitous action potentials). These human genetics studies and recent in utero animal modeling work suggest that precise control of ionic flux (calcium, sodium, and potassium) contributes to in utero developmental processes such as neural proliferation, migration, and differentiation.

Looking to the Future: Speech, Language, and Academic Outcomes in an Adolescent with Childhood Apraxia of Speech

OBJECTIVE

The clinical course of childhood apraxia of speech (CAS) is poorly understood. Of the few longitudinal studies in the field, only one has examined adolescent outcomes in speech, language, and literacy. This study is the first to report long-term speech, language, and academic outcomes in an adolescent, Liam, with CAS.

METHODS

Speech, language, literacy, and academic outcome data were collected, including 3 research-based assessments. Overall, data were available at 17 time points from 3;10 to 15 years.

RESULTS

Liam had moderate-to-severe expressive language impairment and poor reading, writing, and spelling up to 10 years. His numeracy was at or above the national average from 8 to 14 years. He made gains in preadolescence, with average expressive language at 11 years and above average reading and writing at 14 years. Nonword reading, reading comprehension, and spelling remained areas of weakness. Receptive language impairment was evident at 13 years, which was an unexpected finding.

CONCLUSION

Findings from single cases can be hypothesis generating but require verification in larger cohorts. This case shows that at least some children with CAS may gain ground in adolescence, relative to same age peers, in expressive language and academic areas such as reading and writing.

A Psycholinguistic Framework for Diagnosis and Treatment Planning of Developmental Speech Disorders

BACKGROUND

Differential diagnosis and treatment planning of developmental speech disorders (DSD) remains a major challenge in paediatric speech-language pathology. Different classification systems exist, in which subtypes are differentiated based on their theoretical cause and in which the definitions generally refer to speech production processes. Accordingly, various intervention methods have been developed aiming at different parts of the speech production process. Diagnostic classification in these systems, however, is primarily based on a description of behavioural speech symptoms rather than on underlying deficits.

PURPOSE

In this paper, we present a process-oriented approach to diagnosis and treatment planning of DSD. Our framework comprises two general diagnostic categories: developmental delay and developmental disorder. Within these categories, treatment goals/targets and treatment methods are formulated at the level of processes and rules/representations.

CONCLUSION

A process-oriented approach to diagnosis and treatment planning holds important advantages, offering direct leads for treatment aimed at the underlying impairment, tailored to the specific needs of the individual and adjusted to the developmental trajectory.

Characterization of speech and language phenotype in children with NRXN1 deletions

Neurexin 1 gene (NRXN1) deletions are associated with several neurodevelopmental disorders. Communication difficulties have been reported, yet no study has examined specific speech and language features of individuals with NRXN1 deletions. Here, we characterized speech and language phenotypes in 21 children (14 families), aged 1.8-17 years, with NRXN1 deletions. Deletions ranged from 74 to 702 kb and consisted mostly of either exons 1-3 or 1-5. Speech sound disorders were frequent (69%), although few were severe. The majority (57%) of children had difficulty with receptive and/or expressive language, although no homogeneous profiles of deficit were seen across semantic, morphological, or grammatical systems. Social language difficulties were seen in over half the sample (53%). All but two individuals with language difficulties also had intellectual disability/developmental delay. Overall, while speech and language difficulties were common, there was substantial heterogeneity in the severity and type of difficulties observed and no striking communication phenotype was seen. Rather, the speech and language deficits are likely part of broader concomitant neurodevelopmental profiles (e.g., intellectual disability, social skill deficits). Nevertheless, given the high rate of affectedness, it is important speech/language development is assessed so interventions can be applied during childhood in a targeted and timely manner.

Toward the Language Oscillogenome

Language has been argued to arise, both ontogenetically and phylogenetically, from specific patterns of brain wiring. We argue that it can further be shown that core features of language processing emerge from particular phasal and cross-frequency coupling properties of neural oscillations; what has been referred to as the language ‘oscillome.’ It is expected that basic aspects of the language oscillome result from genetic guidance, what we will here call the language ‘oscillogenome,’ for which we will put forward a list of candidate genes. We have considered genes for altered brain rhythmicity in conditions involving language deficits: autism spectrum disorders, schizophrenia, specific language impairment and dyslexia. These selected genes map on to aspects of brain function, particularly on to neurotransmitter function. We stress that caution should be adopted in the construction of any oscillogenome, given the range of potential roles particular localized frequency bands have in cognition. Our aim is to propose a set of genome-to-language linking hypotheses that, given testing, would grant explanatory power to brain rhythms with respect to language processing and evolution.

Aetiology of childhood apraxia of speech: A clinical practice update for paediatricians

Childhood apraxia of speech (CAS) is a rare disorder of childhood that can leave a watermark of the impacts throughout the lifetime. Since being first described in the 1950s, aetiological insights have been limited. At a neurobiological level, clinical MRI scans fail to reveal overt neural anomalies in individual cases with CAS, although quantitative MRI methods have revealed subtle brain anomalies at a group level. Dramatic insights, however, occurred in the past decade from the discovery of genetic pathways underlying the phenotype. Several single genes and copy number-variant conditions are now associated with CAS either in relative isolation, as in the case of FOXP2 variants, or most typically in association with other neurodevelopmental conditions, such as epilepsy, intellectual disability, motor impairment and autism. CAS requires careful differential diagnosis from other childhood speech disorders, but when a severe and persistent diagnosis is confirmed, a genetic aetiology should increasingly be pursued.

[Speech and language neurodevelopmental disorders in epilepsy: pathophysiologic mechanisms and therapeutic approaches]

Speech and language development may be impaired in all forms of epilepsy involving specialized functional areas in the dominant cerebral hemisphere and their connections. The concept of epilepsy-aphasia clinical spectrum was recently proposed, but the notion of aphasia is quite conditional here as many of these patients demonstrate disorders of speech and language development from their infancy. Those forms of epilepsy are considered as continuum from the most severe Landau-Kleffner syndrome (LKS) and epilepsy with continuous spike-and-wave during sleep (CSWS) (also indicating as electrical status epilepticus during sleep - ESES) to intermediate epilepsy-aphasia disorders (with incomplete correspondence to diagnostic criteria of LKS and epilepsy with CSWS). The mild end of the spectrum is represented by benign childhood epilepsy with centrotemporal spikes (rolandic), which is often associated with speech and language disorders. The importance of genetic factors is discussed, including mutations in SRPX2, GRIN2A and other genes. The perspectives of individualized pharmacotherapy in epilepsy, co-morbid with neurodevelopmental disorders or impairments of speech and language development, are depending on the progress in genetic studies. In the new generation of antiepileptic drugs the positive influence on neuroplasticity mechanisms and higher cerebral functions are supposed for levetiracetam.

Sodium Channel SCN3A (NaV1.3) Regulation of Human Cerebral Cortical Folding and Oral Motor Development

Channelopathies are disorders caused by abnormal ion channel function in differentiated excitable tissues. We discovered a unique neurodevelopmental channelopathy resulting from pathogenic variants in SCN3A, a gene encoding the voltage-gated sodium channel Na_V1.3. Pathogenic Na_V1.3 channels showed altered biophysical properties including increased persistent current. Remarkably, affected individuals showed disrupted folding (polymicrogyria) of the perisylvian cortex of the brain but did not typically exhibit epilepsy; they presented with prominent speech and oral motor dysfunction, implicating SCN3A in prenatal development of human cortical language areas. The development of this disorder parallels SCN3A expression, which we observed to be highest early in fetal cortical development in progenitor cells of the outer subventricular zone and cortical plate neurons and decreased postnatally, when SCN1A (Na_V1.1) expression increased. Disrupted cerebral cortical folding and neuronal migration were recapitulated in ferrets expressing the mutant channel, underscoring the unexpected role of SCN3A in progenitor cells and migrating neurons.

SPRINT: an SNP-free toolkit for identifying RNA editing sites

Motivation

RNA editing generates post-transcriptional sequence alterations. Detection of RNA editing sites (RESs) typically requires the filtering of SNVs called from RNA-seq data using an SNP database, an obstacle that is difficult to overcome for most organisms.

Results

Here, we present a novel method named SPRINT that identifies RESs without the need to filter out SNPs. SPRINT also integrates the detection of hyper RESs from remapped reads, and has been fully automated to any RNA-seq data with reference genome sequence available. We have rigorously validated SPRINT’s effectiveness in detecting RESs using RNA-seq data of samples in which genes encoding RNA editing enzymes are knock down or over-expressed, and have also demonstrated its superiority over current methods. We have applied SPRINT to investigate RNA editing across tissues and species, and also in the development of mouse embryonic central nervous system. A web resource (http://sprint.tianlab.cn) of RESs identified by SPRINT has been constructed.

Availability and implementation

The software and related data are available at http://sprint.tianlab.cn.

Supplementary information

Supplementary data are available at Bioinformatics online.

Epilepsy genetics: Current knowledge, applications, and future directions

The rapid pace of disease gene discovery has resulted in tremendous advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, and genomes are now available and have led to higher diagnostic rates and insights into the underlying disease processes. As such, the contribution to the care of patients by medical geneticists, neurogeneticists and genetic counselors are significant; the dysmorphic examination, the necessary pre- and post-test counseling, the selection of the appropriate next-generation sequencing-based test(s), and the interpretation of sequencing results require a care provider to have a comprehensive working knowledge of the strengths and limitations of the available testing technologies. As the underlying mechanisms of the encephalopathies and epilepsies are better understood, there may be opportunities for the development of novel therapies based on an individual's own specific genotype. Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies. The future of epilepsy genetics will also probably include other-omic approaches such as transcriptomes, metabolomes, and the expanded use of whole genome sequencing to further improve our understanding of epilepsy and provide better care for those with the disease.

Interventions for childhood apraxia of speech

BACKGROUND

Childhood apraxia of speech (CAS) affects a child's ability to produce sounds and syllables precisely and consistently, and to produce words and sentences with accuracy and correct speech rhythm. It is a rare condition, affecting only 0.1% of the general population. Consensus has been reached that three core features have diagnostic validity: (1) inconsistent error production on both consonants and vowels across repeated productions of syllables or words; (2) lengthened and impaired coarticulatory transitions between sounds and syllables; and (3) inappropriate prosody (ASHA 2007). A deficit in motor programming or planning is thought to underlie the condition. This means that children know what they would like to say but there is a breakdown in the ability to programme or plan the fine and rapid movements required to accurately produce speech. Children with CAS may also have impairments in one or more of the following areas: non-speech oral motor function, dysarthria, language, phonological production impairment, phonemic awareness or metalinguistic skills and literacy, or combinations of these. High-quality evidence from randomised controlled trials (RCTs) is lacking on interventions for CAS.

OBJECTIVES

To assess the efficacy of interventions targeting speech and language in children and adolescents with CAS as delivered by speech and language pathologists/therapists.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, eight other databases and seven trial registers up to April 2017. We searched the reference lists of included reports and requested information on unpublished trials from authors of published studies and other experts as well as information groups in the areas of speech and language therapy/pathology and linguistics.

SELECTION CRITERIA

RCTs and quasi-RCTs of children aged 3 to 16 years with CAS diagnosed by a speech and language pathologist/therapist, grouped by treatment types.

DATA COLLECTION AND ANALYSIS

Two review authors (FL, AM) independently assessed titles and abstracts identified from the searches and obtained full-text reports of all potentially relevant articles and assessed these for eligibility. The same two authors extracted data and conducted the 'Risk of bias' and GRADE assessments. One review author (EM) tabulated findings from excluded observational studies (Table 1).

MAIN RESULTS

This review includes only one RCT, funded by the Australian Research Council; the University of Sydney International Development Fund; Douglas and Lola Douglas Scholarship on Child and Adolescent Health; Nadia Verrall Memorial Scholarship; and a James Kentley Memorial Fellowship. This study recruited 26 children aged 4 to 12 years, with mild to moderate CAS of unknown cause, and compared two interventions: the Nuffield Dyspraxia Programme-3 (NDP-3); and the Rapid Syllable Transitions Treatment (ReST). Children were allocated randomly to one of the two treatments. Treatments were delivered intensively in one-hour sessions, four days a week for three weeks, in a university clinic in Australia. Speech pathology students delivered the treatments in the English language. Outcomes were assessed before therapy, immediately after therapy, at one month and four months post-therapy. Our review looked at one-month post-therapy outcomes only.We judged all core outcome domains to be low risk of bias. We downgraded the quality of the evidence by one level to moderate due to imprecision, given that only one RCT was identified. Both the NDP-3 and ReST therapies demonstrated improvement at one month post-treatment. A number of cases in each cohort had recommenced usual treatment by their speech and language pathologist between one month and four months post-treatment (NDP-3: 9/13 participants; ReST: 9/13 participants). Hence, maintenance of treatment effects to four months post-treatment could not be analysed without significant potential bias, and thus this time point was not included for further analysis in this review.There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication.

AUTHORS' CONCLUSIONS

There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication. No formal analyses were conducted to compare NDP-3 and ReST by the original study authors, hence one treatment cannot be reliably advocated over the other. We are also unable to say whether either treatment is better than no treatment or treatment as usual. No evidence currently exists to support the effectiveness of other treatments for children aged 4 to 12 years with idiopathic CAS without other comorbid neurodevelopmental disorders. Further RCTs replicating this study would strengthen the evidence base. Similarly, further RCTs are needed of other interventions, in other age ranges and populations with CAS and with co-occurring disorders.

A novel missense mutation in GRIN2A causes a nonepileptic neurodevelopmental disorder

BACKGROUND

Mutations in the GRIN2A gene, which encodes the GluN2A (glutamate [NMDA] receptor subunit epsilon-1) subunit of the N-methyl-d-aspartate receptor, have been identified in patients with epilepsy-aphasia spectrum disorders, idiopathic focal epilepsies with centrotemporal spikes, and epileptic encephalopathies with severe developmental delay. However, thus far, mutations in this gene have not been associated with a nonepileptic neurodevelopmental disorder with dystonia.

OBJECTIVES

The objective of this study was to identify the disease-causing gene in 2 siblings with neurodevelopmental and movement disorders with no epileptiform abnormalities.

METHODS

The study method was targeted next-generation sequencing panel for neuropediatric disorders and subsequent electrophysiological studies.

RESULTS

The 2 siblings carry a novel missense mutation in the GRIN2A gene (p.Ala643Asp) that was not detected in genomic DNA isolated from blood cells of their parents, suggesting that the mutation is the consequence of germinal mosaicism in 1 progenitor. In functional studies, the GluN2A-A643D mutation increased the potency of the agonists L-glutamate and glycine and decreased the potency of endogenous negative modulators, including protons, magnesium and zinc but reduced agonist-evoked peak current response in mammalian cells, suggesting that this mutation has a mixed effect on N-methyl-d-aspartate receptor function.

CONCLUSION

De novo GRIN2A mutations can give rise to a neurodevelopmental and movement disorder without epilepsy. © 2018 International Parkinson and Movement Disorder Society.

Emotional Prosody Processing in Epilepsy: Some Insights on Brain Reorganization

Drug resistant epilepsy is one of the most complex, multifactorial and polygenic neurological syndrome. Besides its dynamicity and variability, it still provides us with a model to study brain-behavior relationship, giving cues on the anatomy and functional representation of brain function. Given that onset zone of focal epileptic seizures often affects different anatomical areas, cortical but limited to one hemisphere, this condition also let us study the functional differences of the left and right cerebral hemispheres. One lateralized function in the human brain is emotional prosody, and it can be a useful ictal sign offering hints on the location of the epileptogenic zone. Besides its importance for effective communication, prosody is not considered an eloquent domain, making resective surgery on its neural correlates feasible. We performed an Electronic databases search (Medline and PsychINFO) from inception to July 2017 for studies about prosody in epilepsy. The search terms included “epilepsy,” “seizure,” “emotional prosody,” and “vocal affect.” This review focus on emotional prosody processing in epilepsy as it can give hints regarding plastic functional changes following seizures (preoperatively), resection (post operatively), and also as an ictal sign enabling the assessment of dynamic brain networks. Moreover, it is argued that such reorganization can help to preserve the expression and reception of emotional prosody as a central skill to develop appropriate social interactions.

Peptide Sharing Between Viruses and DLX Proteins: A Potential Cross-Reactivity Pathway to Neuropsychiatric Disorders

The present study seeks to determine potential associations between viral infections and neuropsychiatric diseases. To address this issue, we investigated the peptide commonalities between viruses that have been related to psychiatric and neurological disorders—such as rubella, human immunodeficiency virus, and herpesviruses—and human distal-less homeobox (DLX) proteins expressed in developing brain—namely, DLX1, DLX2, DLX5, and DLX6. Peptide matching analyses revealed a high degree of pentapeptide sharing. From an immunological perspective, this overlap is relevant because pentapeptides are endowed with immunogenicity and antigenicity—that is, they are immune determinants. Moreover, infection-induced immune cross-reactions might have functional, spatial, and temporal implications related to the functions and expression patterns of DLX1 and DLX5 in the fetal and adult human brain. In sum, our data support the hypothesis that viral infections may be linked to neuropsychiatric diseases through autoimmune cross-reactions caused by molecular mimicry between viral proteins and brain-specific DLX self-antigens.

Ion Channels in Genetic Epilepsy: From Genes and Mechanisms to Disease-Targeted Therapies

Epilepsy is a common and serious neurologic disease with a strong genetic component. Genetic studies have identified an increasing collection of disease-causing genes. The impact of these genetic discoveries is wide reaching-from precise diagnosis and classification of syndromes to the discovery and validation of new drug targets and the development of disease-targeted therapeutic strategies. About 25% of genes identified in epilepsy encode ion channels. Much of our understanding of disease mechanisms comes from work focused on this class of protein. In this study, we review the genetic, molecular, and physiologic evidence supporting the pathogenic role of a number of different voltage- and ligand-activated ion channels in genetic epilepsy. We also review proposed disease mechanisms for each ion channel and highlight targeted therapeutic strategies.

What is the Relationship Between Autism Spectrum Disorders and Epilepsy?

The association of epilepsy and autism spectrum disorders (ASD) is best understood by examining the relationship between social cognition, nonsocial cognition, and epilepsy. The relationship between ASD and epilepsy is bidirectional and is strongly linked to intellectual disability (ID). The risk of developing ASD in children with epilepsy is highest in children with early onset seizures, with a high prevalence in children with infantile spasms. The risk of developing epilepsy in children first diagnosed with ASD is highest in those with ID. The prevalence of seizures in ASD increases with age. When epilepsy and ASD coexist, they share common pathophysiological mechanisms. In epilepsy with and without ID, social-cognitive deficits are an important determinant of neurodevelopmental outcomes. Early recognition of social deficits is an important aspect of the comprehensive management of children with epilepsy. Treating the seizures in individuals with epilepsy and ASD is crucial but interventions that address social-cognitive deficits are necessary to maximize neurodevelopmental outcomes.

BCL11A frameshift mutation associated with dyspraxia and hypotonia affecting the fine, gross, oral, and speech motor systems

We report the case of a 7‐year‐old male of Western European origin presenting with moderate intellectual disability, severe childhood apraxia of speech in the presence of oral and manual dyspraxia, and hypotonia across motor systems including the oral and speech motor systems. Exome sequencing revealed a de novo frameshift protein truncating mutation in the fourth exon of BCL11A, a gene recently demonstrated as being involved in cognition and language development. Making parallels with a previously described patient with a 200 kb 2p15p16.1 deletion encompassing the entire BCL11A gene and displaying a similar phenotype, we characterize in depth how BCL11A is involved in clinical aspects of language development and oral praxis.

Epilepsy in patients with GRIN2A alterations: Genetics, neurodevelopment, epileptic phenotype and response to anticonvulsive drugs

OBJECTIVE

To delineate the genetic, neurodevelopmental and epileptic spectrum associated with GRIN2A alterations with emphasis on epilepsy treatment.

METHODS

Retrospective study of 19 patients (7 females; age: 1-38 years; mean 10.1 years) with epilepsy and GRIN2A alteration. Genetic variants were classified according to the guidelines and recommendations of the American College of Medical Genetics (ACMG). Clinical findings including epilepsy classification, treatment, EEG findings, early childhood development and neurodevelopmental outcome were collected with an electronic questionnaire.

RESULTS

7 out of 19 patients fulfilled the ACMG-criteria of carrying "pathogenic" or "likely pathogenic variants", in twelve patients the alterations were classified as variants of unknown significance. The spectrum of pathogenic/likely pathogenic mutations was as follows: nonsense n = 3, missense n = 2, duplications/deletions n = 1 and splice site n = 1. First seizures occurred at a mean age of 2.4 years with heterogeneous seizure types. Patients were treated with a mean of 5.6 AED. 4/5 patients with VPA had an improved seizure frequency (n = 3 with a truncation: n = 1 missense). 3/5 patients with STM reported an improvement of seizures (n = 2 truncation, n = 1 splicing). 3/5 CLB patients showed an improvement (n = 2: truncation; n = 1 splicing). Steroids were reported to have a positive effect on seizure frequency in 3/5 patients (n = 1 each truncation, splicing or deletion).

CONCLUSIONS

Our data indicate that children with epilepsy due to pathogenic GRIN2A mutations present with different clinical phenotypes and a spectrum of seizure types in the context of a pharmacoresistant epilepsy providing information for clinicians treating children with this form of genetically determined epileptic syndrome.

Dysarthria and broader motor speech deficits in Dravet syndrome

OBJECTIVE

To analyze the oral motor, speech, and language phenotype in 20 children and adults with Dravet syndrome (DS) associated with mutations in SCN1A.

METHODS

Fifteen verbal and 5 minimally verbal DS patients with SCN1A mutations (aged 15 months-28 years) underwent a tailored assessment battery.

RESULTS

Speech was characterized by imprecise articulation, abnormal nasal resonance, voice, and pitch, and prosody errors. Half of verbal patients had moderate to severely impaired conversational speech intelligibility. Oral motor impairment, motor planning/programming difficulties, and poor postural control were typical. Nonverbal individuals had intentional communication. Cognitive skills varied markedly, with intellectual functioning ranging from the low average range to severe intellectual disability. Language impairment was congruent with cognition.

CONCLUSIONS

We describe a distinctive speech, language, and oral motor phenotype in children and adults with DS associated with mutations in SCN1A. Recognizing this phenotype will guide therapeutic intervention in patients with DS.

Cognitive, Linguistic, and Motor Abilities in a Multigenerational Family with Childhood Apraxia of Speech

Objective

This study describes the phenotype in a large family with a strong, multigenerational history of severe speech sound disorder (SSD) persisting into adolescence and adulthood in approximately half the cases. Aims were to determine whether a core phenotype, broader than speech, separated persistent from resolved SSD cases; and to ascertain the uniqueness of the phenotype relative to published cases.

Method

Eleven members of the PM family (9–55 years) were assessed across cognitive, language, literacy, speech, phonological processing, numeracy, and motor domains. Between group comparisons were made using the Mann–WhitneyU-test (p < 0.01). Participant performances were compared to normative data using standardized tests and to the limited published data on persistent SSD phenotypes.

Results

Significant group differences were evident on multiple speech, language, literacy, phonological processing, and verbal intellect measures without any overlapping scores. Persistent cases performed within the impaired range on multiple measures. Phonological memory impairment and subtle literacy weakness were present in resolved SSD cases.

Conclusion

A core phenotype distinguished persistent from resolved SSD cases that was characterized by a multiple verbal trait disorder, including Childhood Apraxia of Speech. Several phenotypic differences differentiated the persistent SSD phenotype in the PM family from the few previously reported studies of large families with SSD, including the absence of comorbid dysarthria and marked orofacial apraxia. This study highlights how comprehensive phenotyping can advance the behavioral study of disorders, in addition to forming a solid basis for future genetic and neural studies.

Bridging the Gap between Genes and Language Deficits in Schizophrenia: An Oscillopathic Approach

Schizophrenia is characterized by marked language deficits, but it is not clear how these deficits arise from the alteration of genes related to the disease. The goal of this paper is to aid the bridging of the gap between genes and schizophrenia and, ultimately, give support to the view that the abnormal presentation of language in this condition is heavily rooted in the evolutionary processes that brought about modern language. To that end we will focus on how the schizophrenic brain processes language and, particularly, on its distinctive oscillatory profile during language processing. Additionally, we will show that candidate genes for schizophrenia are overrepresented among the set of genes that are believed to be important for the evolution of the human faculty of language. These genes crucially include (and are related to) genes involved in brain rhythmicity. We will claim that this translational effort and the links we uncover may help develop an understanding of language evolution, along with the etiology of schizophrenia, its clinical/linguistic profile, and its high prevalence among modern populations.

New genes for focal epilepsies with speech and language disorders

The last 2 years have seen exciting advances in the genetics of Landau-Kleffner syndrome and related disorders, encompassed within the epilepsy-aphasia spectrum (EAS). The striking finding of mutations in the N-methyl-D-aspartate (NMDA) receptor subunit gene GRIN2A as the first monogenic cause in up to 20% of patients with EAS suggests that excitatory glutamate receptors play a key role in these disorders. Patients with GRIN2A mutations have a recognizable speech and language phenotype that may assist with diagnosis. Other molecules involved in RNA binding and cell adhesion have been implicated in EAS; copy number variations are also found. The emerging picture highlights the overlap between the genetic determinants of EAS with speech and language disorders, intellectual disability, autism spectrum disorders and more complex developmental phenotypes.

Induction Immunosuppression in High-risk Kidney Transplant Recipients

Kidney transplant remains the best type of renal replacement therapy in most patients with end-stage kidney disease, even in those with high immunologic risk. Immunosuppression in these patients is regarded as more complex, owing to the higher risk of both acute and chronic rejection. The advent of induction immunosuppression has resulted in a lower incidence of acute rejection and consequently improved short-term patient and allograft outcomes. Indeed, the use of these agents, especially in high-risk recipients, has become standard of care at most transplant centers. Transplant physicians are constantly faced with the challenge of estimating the recipients' immunologic risk and tailoring their immunosuppression accordingly. This review article aims to provide an up-to-date evaluation of the various studies available, which investigated the use of induction agents in kidney transplant, specifically in high-risk recipients. It evaluates the use of the most frequently used polyclonal antibody (rabbit antithymocyte globulin) versus the less commonly used monoclonal antibody alemtuzumab, superseded agents such as muromonab-CD3, and potentially emerging agents such as rituximab, bortezomib, and eculizumab. With this systematic review, we hope to inform the scientific community and facilitate this controversial decision through the implementation of robust scientific evidence.

Understanding Neuropsychiatric Diseases, Analyzing the Peptide Sharing between Infectious Agents and the Language-Associated NMDA 2A Protein

Language disorders and infections may occur together and often concur, to a different extent and via different modalities, in characterizing brain pathologies, such as schizophrenia, autism, epilepsies, bipolar disorders, frontotemporal neurodegeneration, and encephalitis, inter alia. The biological mechanism(s) that might channel language dysfunctions and infections into etiological pathways connected to neuropathologic sequelae are unclear. Searching for molecular link(s) between language disorders and infections, the present study explores the language-associated NMDA 2A subunit for peptide sharing with pathogens that have been described in concomitance with neuropsychiatric diseases. It was found that a vast peptide commonality links the human glutamate ionotropic receptor NMDA 2A subunit to infectious agents. Such a link expands to and interfaces with neuropsychiatric disorders in light of the specific allocation of NMDA 2A gene expression in brain areas related to language functions. The data hint at a possible pathologic scenario based on anti-pathogen immune responses cross-reacting with NMDA 2A in the brain.