0000000000292368
AUTHOR
Pasquale Striano
Electroclinical features and outcome of ANKRD11-related KBG syndrome: A novel report and literature review.
KBG syndrome (OMIM #148050) is a rare autosomal dominant disorder, typically characterized by macrodontia of the upper central incisors, distinct craniofacial findings, short stature, and skeletal anomalies associated with neurological involvement including intellectual disability, behaviour difficulties, and epilepsy. KBG syndrome is associated with mutations in ANKRD11 gene that plays a chromatin regulator role of histone acetylation and gene expression during neurogenesis in the embryonic brain.
Efficacy of levetiracetam in the treatment of drug-resistant Rett Syndrome.
Rett syndrome (RTT) is a progressive neurological disorder characterized by a wide spectrum of phenotypes. Epilepsy is reported to occur in 50–90% of patients with RTT; some develop medically refractory epilepsy. The aim of this study is to investigate the efficacy of levetiracetam (LEV) in drug-resistant patients with RTT. This prospective, pragmatic, open-label study consisted of an 8-week baseline period and a 6-month evaluation period. Efficacy variable was the mean frequency of monthly seizures before, and after 3 and 6 months of treatment with LEV. Eight female patients, aged 7.5–19 years (M12.8 ± 5) entered the study. Mean age at epilepsy onset was 25.8 ± 14.1 months. All patients sh…
De novo GRIN2A variants associated with epilepsy and autism and literature review
N-methyl-D-aspartate receptors (NMDAR) are di- or tri-heterotetrameric ligand-gated ion channels composed of two obligate glycine-binding GluN1 subunits and two glutamate-binding GluN2 or GluN3 subunits, encoded by GRIN1, GRIN2A–D, and GRIN3A–B receptor genes respectively. Each NMDA receptor subtype has different temporal and spatial expression patterns in the brain and varies in the cell types and subcellular localization resulting in different functions. They play a crucial role in mediating the excitatory neurotransmission, but are also involved in neuronal development and synaptic plasticity, essential for learning, memory, and high cognitive functions. Among genes coding NMDAR subunits…
Clinical Significance of Rare Copy Number Variations in Epilepsy A Case-Control Survey Using Microarray-Based Comparative Genomic Hybridization
Objective To perform an extensive search for genomic rearrangements by microarray-based comparative genomic hybridization in patients with epilepsy. Design Prospective cohort study. Setting Epilepsy centers in Italy. Patients Two hundred seventy-nine patients with unexplained epilepsy, 265 individuals with nonsyndromic mental retardation but no epilepsy, and 246 healthy control subjects were screened by microarray-based comparative genomic hybridization. Main Outcomes Measures Identification of copy number variations (CNVs) and gene enrichment. Results Rare CNVs occurred in 26 patients (9.3%) and 16 healthy control subjects (6.5%) (P = .26). The CNVs identified in patients were larger (P = …
PRRT2 mutations are the major cause of benign familial infantile seizures.
Mutations in PRRT2 have been described in paroxysmal kinesigenic dyskinesia (PKD) and infantile convulsions with choreoathetosis (PKD with infantile seizures), and recently also in some families with benign familial infantile seizures (BFIS) alone. We analyzed PRRT2 in 49 families and three sporadic cases with BFIS only of Italian, German, Turkish, and Japanese origin and identified the previously described mutation c.649dupC in an unstable series of nine cytosines to occur in 39 of our families and one sporadic case (77% of index cases). Furthermore, three novel mutations were found in three other families, whereas 17% of our index cases did not show PRRT2 mutations, including a large fami…
Structural mapping of GABRB3 variants reveals genotype-phenotype correlations
AbstractPurposePathogenic variants in GABRB3 have been associated with a spectrum of phenotypes from severe developmental disorders and epileptic encephalopathies to milder epilepsy syndromes and mild intellectual disability. In the present study, we analyzed a large cohort of individuals with GABRB3 variants to deepen the phenotypic understanding and investigate genotype-phenotype correlations.MethodsThrough an international collaboration, we analyzed electro-clinical data of unpublished individuals with variants in GABRB3 and we reviewed previously published cases. All missense variants were mapped onto the 3D structure of the GABRB3 subunit and clinical phenotypes associated with the dif…
Correction: The landscape of epilepsy-related GATOR1 variants
International audience; The original version of this article contained an error in the spelling of the author Erik H. Niks, which was incorrectly given as Erik Niks. This has now been corrected in both the PDF and HTML versions of the article.
Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification
International audience; Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromo…
The landscape of epilepsy-related GATOR1 variants
Purpose:\ud \ud To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway.\ud \ud Methods:\ud \ud We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants.\ud \ud Results:\ud \ud The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia…
A novel KCNQ3 mutation in familial epilepsy with focal seizures and intellectual disability
Mutations in the KCNQ2 gene encoding for voltage-gated potassium channel subunits have been found in patients affected with early onset epilepsies with wide phenotypic heterogeneity, ranging from benign familial neonatal seizures (BFNS) to epileptic encephalopathy with cognitive impairment, drug resistance, and characteristic electroencephalography (EEG) and neuroradiologic features. By contrast, only few KCNQ3 mutations have been rarely described, mostly in patients with typical BFNS. We report clinical, genetic, and functional data from a family in which early onset epilepsy and neurocognitive deficits segregated with a novel mutation in KCNQ3 (c.989G>T; p.R330L). Electrophysiological stu…
Clinico-diagnostic features of neuralgic amyotrophy in childhood
Neuralgic amyotrophy (NA), even known as Personage-Turner's syndrome (PTS), is a neurologic condition, affecting the lower motor neurons of brachial plexus and/or individual nerves or nerve branches, characterized by pain, muscle weakness/atrophy, and sensory symptoms. NA has an acute/subacute onset, after an infection or vaccination; it is more common in male and is rare in the pediatric population. The etiology remains uncertain, being considered heterogeneous and multifactorial. A severe acute neurologic pain around the shoulder girdle is the classic presenting symptom at onset. As the pain subsides, weakness and paresis develop. NA is usually unilateral, but sometimes, a subclinical con…
Mutations in the Neuronal Vesicular SNARE VAMP2 Affect Synaptic Membrane Fusion and Impair Human Neurodevelopment
VAMP2 encodes the vesicular SNARE protein VAMP2 (also called synaptobrevin-2). Together with its partners syntaxin-1A and synaptosomal-associated protein 25 (SNAP25), VAMP2 mediates fusion of synaptic vesicles to release neurotransmitters. VAMP2 is essential for vesicular exocytosis and activity-dependent neurotransmitter release. Here, we report five heterozygous de novo mutations in VAMP2 in unrelated individuals presenting with a neurodevelopmental disorder characterized by axial hypotonia (which had been present since birth), intellectual disability, and autistic features. In total, we identified two single-amino-acid deletions and three non-synonymous variants affecting conserved resid…
Chromosome 15q BP4-BP5 Deletion in a Girl with Nocturnal Frontal Lobe Epilepsy, Migraine, Circumscribed Hypertrichosis, and Language Impairment
The 15q13.3 microdeletion (microdel15q13.3) syndrome (OMIM 612001) has been reported in healthy subjects as well as in individuals with a wide spectrum of clinical manifestations ranging from mild to severe neurological disorders, including developmental delay/intellectual disability, autism spectrum disorder, schizophrenia, epilepsy, behavioral problems and speech dysfunction. This study explored the link between this genomic rearrangement and nocturnal frontal lobe epilepsy (NFLE), which could improve the clinical interpretation. A clinical and genomic investigation was carried out on an 8-year-girl with a de novo deletion flanking the breakpoints (BPs) 4 and 5 of 15q13.3 detected by arra…
HCN1 mutation spectrum: from neonatal epileptic encephalopathy to benign generalized epilepsy and beyond
International audience; Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control neuronal excitability and their dysfunction has been linked to epileptogenesis but few individuals with neurological disorders related to variants altering HCN channels have been reported so far. In 2014, we described five individuals with epileptic encephalopathy due to de novo HCN1 variants. To delineate HCN1-related disorders and investigate genotype-phenotype correlations further, we assembled a cohort of 33 unpublished patients with novel pathogenic or likely pathogenic variants: 19 probands carrying 14 different de novo mutations and four families with dominantly inherited variants segre…
Linkage analysis and disease models in benign familial infantile seizures: a study of 16 families.
Summary: Purpose: Benign familial infantile seizures (BFIS) is a genetically heterogeneous condition characterized by partial seizures, onset age from 3 to 9 months, and favorable outcome. BFIS loci were identified on chromosomes 19q12-13.1 and 16p12-q12, allelic to infantile convulsions and choreathetosis. The identification of SCN2A mutations in families with only infantile seizures indicated that BFNIS and BFIS may show overlapping clinical features. Infantile seizures also were in a family with familial hemiplegic migraine and mutations in the ATP1A2 gene. We have examined the heterogeneous genetics of BFIS by means of linkage analysis. Methods: Sixteen families were examined. Probands …
PDXK mutations cause polyneuropathy responsive to pyridoxal 5′‐phosphate supplementation
OBJECTIVE: To identify disease-causing variants in autosomal recessive axonal polyneuropathy with optic atrophy and provide targeted replacement therapy. METHODS: We performed genome-wide sequencing, homozygosity mapping, and segregation analysis for novel disease-causing gene discovery. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the impact of variants on adenosine triphosphate (ATP) binding. Pathogenicity was further supported by enzymatic assays and mass spectroscopy on recombinant protein, patient-derived fibroblasts, plasma, and erythrocytes. Response to supplementation was measured with clinical validated rating sc…