Single nucleotide variations in CLCN6 identified in patients with benign partial epilepsies in infancy and/or febrile seizures.

Nucleotide alterations in the gene encoding proline-rich transmembrane protein 2 (PRRT2) have been identified in most patients with benign partial epilepsies in infancy (BPEI)/benign familial infantile epilepsy (BFIE). However, not all patients harbor these PRRT2 mutations, indicating the involvement of genes other than PRRT2. In this study, we performed whole exome sequencing analysis for a large family affected with PRRT2-unrelated BPEI.

Brain magnetic resonance imaging and outcome after hypoxic ischaemic encephalopathy.

Objective: To correlate pattern of injury on neonatal brain magnetic resonance imaging (MRI) with outcome in infants ≥36 + 0 weeks gestation with hypoxic ischaemic encephalopathy.

Methods: Prospective cohort study. Images were blindly reviewed.

Early-onset epileptic encephalopathy caused by gain-of-function mutations in the voltage sensor of Kv7.2 and Kv7.3 potassium channel subunits.

Mutations in Kv7.2 (KCNQ2) and Kv7.3 (KCNQ3) genes, encoding for voltage-gated K(+) channel subunits underlying the neuronal M-current, have been associated with a wide spectrum of early-onset epileptic disorders ranging from benign familial neonatal seizures to severe epileptic encephalopathies.

Benign infantile seizures.

Background: Benign infantile seizures are a common form of idiopathic seizures in infants, but infrequently reported.

Case Characteristics: Four cases identified over a 9-month period.

Observation: All had a cluster of focal seizures, normal development and no abnormality on hematological and biochemical work-up.

Common pediatric epilepsy syndromes.

Benign rolandic epilepsy (BRE), childhood idiopathic occipital epilepsy (CIOE), childhood absence epilepsy (CAE), and juvenile myoclonic epilepsy (JME) are some of the common epilepsy syndromes in the pediatric age group. Among the four, BRE is the most commonly encountered. BRE remits by age 16 years with many children requiring no treatment.

[Phenotypes and PRRT2 mutation analysis in families with benign familial infantile epilepsy].

Objective: To study the phenotypes and proline-rich transmembrane protein 2 (PRRT2) mutations in families with benign familial infantile epilepsy (BFIE).

Method: Data of all BFIE probands and their family members were collected from Peking University First Hospital between September 2006 and August 2013. Clinical phenotypes of affected members were analyzed.

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.

[Clinical features and PRRT2 mutations in infantile convulsions with paroxysmal choreoathetosis].

Objective: To analyze the phenotypes and proline-rich transmenbrane protein 2 (PRRT2) gene mutations in patients of infantile convulsions with paroxysmal choreoathetosis (ICCA).

Methods: Clinical data were collected from ICCA patients and their family members. Genomic DNA was extracted from peripheral blood samples with standard protocol.

Reduced Penetrance of PRRT2 Mutation in a Chinese Family With Infantile Convulsion and Choreoathetosis Syndrome.

Paroxysmal kinesigenic dyskinesia is a rare episodic movement disorder that can be isolated or associated with benign infantile seizures as part of choreoathetosis syndrome. Mutations in the PRRT2 gene have been recently identified as a cause of paroxysmal kinesigenic dyskinesia and infantile convulsion and choreoathetosis (ICCA). We reported a PRRT2 heterozygous mutation (c.

Capturing distinct KCNQ2 channel resting states by metal ion bridges in the voltage-sensor domain.

Although crystal structures of various voltage-gated K(+) (Kv) and Na(+) channels have provided substantial information on the activated conformation of the voltage-sensing domain (VSD), the topology of the VSD in its resting conformation remains highly debated. Numerous studies have investigated the VSD resting state in the Kv Shaker channel; however, few studies have explored this issue in other Kv channels. Here, we investigated the VSD resting state of KCNQ2, a K(+) channel subunit belonging to the KCNQ (Kv7) subfamily of Kv channels.

Sudden infant death syndrome, sleep, and seizures.

benign febrile seizures seen in 7% of infants before 6 months play a role in the terminal pathway in a subset of sudden infant death syndrome victims. Supporting evidence: (1) lack of 5-hydroxitryptamine, one consistent finding in sudden infant death syndrome that Kinney et al coined a developmental serotonopathy, is consistent with risk for seizures. (2) Non-rapid eye movement sleep increasing during the age of highest risk for sudden infant death syndrome facilitates some seizures (seizure gate).

[PRRT2 gene-related paroxysmal disorders].

Proline-rich transmembrane protein 2 (PRRT2), the causative gene of paroxysmal kinesigenic dyskinesias (PKD), benign familial infantile seizures (BFIS) and infantile convulsions with paroxysmal choreoathetosis (ICCA), also causes a variety of neurological paroxysmal disorders. These diseases share the same characteristics which may be due to the same genetic defect. We therefore propose to name them as PRRT2-related paroxysmal disorders (PRPDs) in order to assist clinical diagnosis, treatment and prognosis.

The human ether-a-go-go-related gene activator NS1643 enhances epilepsy-associated KCNQ channels.

Human ether-a-go-go-related gene (hERG) and KCNQ channels are two classes of voltage-gated potassium channels. Specific mutations have been identified that are causal for type II long QT (LQT2) syndrome, neonatal epilepsy, and benign familial neonatal convulsions. Increasing evidence from clinical studies suggests that LQT2 and epilepsy coexist in some patients.

PRRT2: a major cause of infantile epilepsy and other paroxysmal disorders of childhood.

In the past 2 years, mutations in the PRRT2 gene have been identified in patients and families with a variety of early-onset paroxysmal disorders, including various paroxysmal dyskinesias, benign familial infantile seizures, hemiplegic migraine, and episodic ataxia. In this chapter, we describe the wide clinical spectrum associated with PRRT2 mutations and present the current hypotheses on the underlying pathophysiology. Through its interaction with the presynaptic plasma membrane protein SNAP25, the PRRT2 protein may play a role in synaptic regulation in the cortex and basal ganglia.

Mechanisms underlying epilepsies associated with sodium channel mutations.

Voltage-gated sodium channels provide the molecular basis for the generation and propagation of action potentials. It is therefore not surprising that mutations in different subunits of this ion channel family are the most common cause of genetic epilepsies. Voltage-gated sodium channel mutations are associated with different seizure phenotypes including benign familial neonatal-infantile convulsions, genetic epilepsy with febrile seizures plus, and Dravet syndrome.

Potassium channel genes and benign familial neonatal epilepsy.

Several potassium channel genes have been implicated in different neurological disorders including genetic and acquired epilepsy. Among them, KCNQ2 and KCNQ3, coding for KV7.2 and KV7.

Genetic forms of epilepsies and other paroxysmal disorders.

Genetic mechanisms explain the pathophysiology of many forms of epilepsy and other paroxysmal disorders, such as alternating hemiplegia of childhood, familial hemiplegic migraine, and paroxysmal dyskinesias. Epilepsy is a key feature of well-defined genetic syndromes including tuberous sclerosis complex, Rett syndrome, Angelman syndrome, and others. There is an increasing number of single-gene causes or susceptibility factors associated with several epilepsy syndromes, including the early-onset epileptic encephalopathies, benign neonatal/infantile seizures, progressive myoclonus epilepsies, genetic generalized and benign focal epilepsies, epileptic aphasias, and familial focal epilepsies.

Exacerbation of benign familial neonatal epilepsy induced by massive doses of phenobarbital and midazolam.

Background: Barbiturates and benzodiazepines are the first-line anticonvulsants for neonatal seizures. However, in immature brains, those drugs may lead to paradoxical neuronal excitation.

Patient: A patient with benign familial neonatal epilepsy developed epileptic encephalopathy after massive doses of phenobarbital that were followed by a continuous infusion of midazolam on postnatal day 3.

Atypical course in individuals from Spanish families with benign familial infantile seizures and mutations in the PRRT2 gene.

A benign prognosis has been claimed in benign familial infantile seizures (BFIS). However, few studies have assessed the long-term evolution of these patients. The objective of this study is to describe atypical courses and presentations in BFIS families with mutations in PRRT2 gene.

The variable phenotypes of KCNQ-related epilepsy.

Mutations in KCNQ2 and KCNQ3 were originally described in infants with benign familial neonatal seizures (BFNS). Recently, KCNQ2 mutations have also been shown to cause epileptic encephalopathy. This report describes three infants carrying abnormalities of KCNQ2 and one infant with a KCNQ3 mutation.

Benign infantile convulsion as a diagnostic clue of paroxysmal kinesigenic dyskinesia: a case series.

Introduction: Paroxysmal kinesigenic dyskinesia is characterized by sudden attacks of involuntary movements. It is often misdiagnosed clinically as psychogenic illness, which distresses the patients to a great extent. A correct diagnosis will improve the quality of life in patients with paroxysmal kinesigenic dyskinesia because treatment with low doses of anticonvulsants is effective for eliminating the clinical manifestations.

Unusual variability of PRRT2 linked phenotypes within a family.

Background: Mutations in the proline-rich transmembrane protein 2 (PRRT2) gene on chromosome 16p11.2 have recently been identified as a cause of paroxysmal kinesigenic dyskinesias (PKD), infantile convulsions and choreoathetosis (ICCA) syndrome or infantile convulsions (IC).

Aims: Here, we describe a family with four affected members.

Benign neonatal sleep myoclonus: our experience of 15 Japanese cases.

Purpose: Benign neonatal sleep myoclonus is a non-epileptic movement disorder that may mimic neonatal seizures. The aim of this study was to clarify the clinical manifestations and outcomes in Japanese infants with benign neonatal sleep myoclonus.

Methods: We reviewed the clinical manifestations and outcomes in 15 consecutive patients with benign neonatal sleep myoclonus (males: 10), including three paired familial cases, referred to our center between 1996 and 2011.

Localization of the epileptogenic foci in tuberous sclerosis complex: a pediatric case report.

Tuberous sclerosis complex (TSC) is a rare disorder of tissue growth and differentiation, characterized by benign hamartomas in the brain and other organs. Up to 90% of TSC patients develop epilepsy and 50% become medically intractable requiring resective surgery. The surgical outcome of TSC patients depends on the accurate identification of the epileptogenic zone consisting of tubers and the surrounding epileptogenic tissue.

Infantile epileptic encephalopathy, transient choreoathetotic movements, and hypersomnia due to a De Novo missense mutation in the SCN2A gene.

Mutations of the SCN2A gene have originally been described in association with benign familial neonatal-infantile seizures (BFNIS). Recently, single patients with more severe phenotypes and persisting epileptic encephalopathies have been recognized. We report the case of a girl with severe infantile onset epileptic encephalopathy and a de novo missense mutation in the SCN2A gene (c.