No abstract available.
Epilepsy, Benign Neonatal*

Epilepsy, Benign Neonatal ; genetics ; Humans

OBJECTIVEThe present study performed linkage analysis and gene mapping to find the possible chromosome locus harboring in one family with benign familial infantile convulsions (BFIC) and investigate the possible molecular pathogenesis of BFIC.

METHODSA four-generation family with BFIC was investigated. The family was genotyped using eight hypervariable microsatellite markers covering four loci: D19S245 and D19S250 for the 19q12-13.1 region, D16S3131 and D16S3133 for the 16p12-q12 region, D2S156 and D2S286 for the 2q24 region, and D20S480 and D20S481 for the 20q13.3 region. Polymorphism fragments were amplified using polymerase chain reaction (PCR) method. PCR products for the markers were subjected to electrophoresis on 8% denatured polyacrylamide gel and silver staining for length judgment of amplification fragment. Linkage analysis was performed by use of MLINK in the LINKAGE computer package. Two-point LOD scores were calculated to estimate the linkage relationship.

RESULTSThe two-point LOD scores were less than -2.0 for the genetic markers at chromosomes 19q12-13.1, 16p12-q12 and 2q24 at the recombination rate between 0.000 and 0.01. The two-point LOD scores for D20S481 at the 20q13.3 region were 0.3 and 0.25 at the recombination rate of 0.000 and 0.01, respectively.

CONCLUSIONSThere is no evidence that this family with BFIC is linked to one of the following loci: 19q12-13.1, 16p12-q12 and 2q24, but a possible linkage with 20q13.3 region cannot be excluded.

Chromosome Mapping ; Epilepsy, Benign Neonatal ; genetics ; Female ; Genetic Linkage ; Humans ; Lod Score ; Male ; Microsatellite Repeats

Benign idiopathic neonatal convulsion is a rare disorder which has no family history of convulsion and develops before and after the 5th day in a healthy full-term neonate. Its characteristics appear focal, or multifocal clonic seizures but rare tonic seizures lasting about several minutes. It reveals non-specific findings in neurologic examination, neuroimaging and EEG(electroencephalography) so that it should be differentiated from those diseases such as eletronic imbalance, inborn errors of metabolism, other neonatal epileptic syndromes. We report two healthy full-term female neonates presented with multifocal clonic seizures before and after the 5th day after birth. They had no family history of convulsion, fetal asphyxia, fetal and maternal problems and the neurologic examination and neuroimagings were normal. The convulsions were controlled by intravenous phenobarbital injection. They had no more convulsions ever since and showed normal development at the follow-up performed one year later. We experienced a rare disorder, benign neonatal convulsion in healthy full-term neonates. We hope this report will help its diagnosis and treatment and prevent unnecessary long- term anticonvulsant medication.
Asphyxia ; Epilepsy, Benign Neonatal ; Female ; Follow-Up Studies ; Humans ; Infant, Newborn ; Metabolism, Inborn Errors ; Neuroimaging ; Neurologic Examination ; Parturition ; Phenobarbital ; Seizures

OBJECTIVE: To analyze the clinical phenotype and genetic variant in a Chinese pedigree affected with benign familial neonatal convulsion (BFNC). METHODS: Clinical data and peripheral blood samples of the pedigree were obtained with informed consent. Whole exome sequencing (WES) was carried out for the proband. Candidate variants were verified by Sanger sequencing. RESULTS: The pedigree comprised 9 individuals, among whom 4 were affected, including 3 males and 1 female. All patients had developed seizures during the neonatal period, which had ceased in 4 to 6 months. One patient had recurrence in between 1 and 2 years old. Genetic testing has identified a novel nonsense c.810G>A (p.W270X) variant in exon 5 of the KCNQ2 gene, which has co-separated with the BFNC phenotype in the pedigree. CONCLUSION The patients from this pedigree have conformed to the diagnosis of BFNC with good prognosis, which was in keeping with previously reported cases. The heterozygous c.810G>A (p.W270X) nonsense variant of the KCNQ2 gene probably underlay the pathogenesis of BFNC in this pedigree, which has expanded the mutational spectrum of the disease.
Asians/genetics* ; Child, Preschool ; China ; Epilepsy, Benign Neonatal/genetics* ; Female ; Genetic Testing ; Humans ; Infant ; Male ; Mutation ; Pedigree

Proline-rich transmembrane protein 2 (PRRT2) is the leading cause of paroxysmal kinesigenic dyskinesia (PKD), benign familial infantile epilepsy (BFIE), and infantile convulsions with choreoathetosis (ICCA). Reduced penetrance of PRRT2 has been observed in previous studies, whereas the exact penetrance has not been evaluated well. The objective of this study was to estimate the penetrance of PRRT2 and determine its influencing factors. We screened 222 PKD index patients and their available relatives, identified 39 families with pathogenic or likely pathogenic (P/LP) PRRT2 variants via Sanger sequencing, and obtained 184 PKD/BFIE/ICCA families with P/LP PRRT2 variants from the literature. Penetrance was estimated as the proportion of affected variant carriers. PRRT2 penetrance estimate was 77.6% (95% confidence interval (CI) 74.5%-80.7%) in relatives and 74.5% (95% CI 70.2%-78.8%) in obligate carriers. In addition, we first observed that penetrance was higher in truncated than in non-truncated variants (75.8% versus 50.0%, P = 0.01), higher in Asian than in Caucasian carriers (81.5% versus 68.5%, P = 0.004), and exhibited no difference in gender or parental transmission. Our results are meaningful for genetic counseling, implying that approximately three-quarters of PRRT2 variant carriers will develop PRRT2-related disorders, with patients from Asia or carrying truncated variants at a higher risk.
Dystonia ; Epilepsy, Benign Neonatal/genetics* ; Humans ; Membrane Proteins/genetics* ; Mutation ; Nerve Tissue Proteins/genetics* ; Pedigree ; Penetrance ; Seizures/genetics*

OBJECTIVETo study the clinical features and prognosis of benign infantile convulsions associated with mild gastroenteritis (BICE).

METHODSA retrospective analysis was performed for the clinical data of 436 children with BICE, and among these children, 206 were followed up for 1.5 to 7 years. Some parents were invited to complete the Weiss Functional Defect Scale to evaluate the long-term social function.

RESULTSThe peak age of onset of BICE was 13-24 months, and BICE had a higher prevalence rate in September to February of the following year. Convulsions mainly manifested as generalized tonic-clonic seizures, which often occurred within 24 hours after disease onset and lasted for less than 5 minutes each time. Sometimes they occurred in clusters. During the follow-up of 206 children, only one had epileptiform discharge, and the other children had normal electroencephalographic results. The parents of all the 206 children thought their children had normal intelligence and had no marked changes in character. Based on the Weiss Functional Defect Scale completed by the parents of some BICE children, there was no significant difference in the long-term social function between BICE children and healthy children matched by age and sex.

CONCLUSIONSBICE mainly occurs in children aged 1-2 years, with the manifestation of transient generalized seizures in most children and cluster seizures in some children. BICE seldom progresses to epilepsy and has good prognosis.

Child, Preschool ; Electroencephalography ; Epilepsy, Benign Neonatal ; diagnosis ; drug therapy ; etiology ; Female ; Follow-Up Studies ; Gastroenteritis ; diagnosis ; drug therapy ; etiology ; Humans ; Infant ; Male ; Prognosis ; Retrospective Studies

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. This paper has reviewed the clinical phenotype, common features and pathogenesis of the PRPDs.
Chorea ; genetics ; Epilepsy, Benign Neonatal ; genetics ; Family Health ; Genetic Predisposition to Disease ; genetics ; Humans ; Infant ; Infant, Newborn ; Membrane Proteins ; genetics ; Mutation ; Nerve Tissue Proteins ; genetics

Neonatal seizures represent a heterogeneous group of disorders with vastly different etiologies and outcomes. Benign familial neonatal convulsions (BFNC) are a distinctive epileptic syndrome of autosomal dominant inheritance with a favorable prognosis, characterized by the occurrence of unprovoked partial or generalized clonic seizures in the neonatal period or early infancy. Recently, mutations in two potassium channel genes, KCNQ2 and KCNQ3, have been described in this disorder. In this report, we describe a family with BFNC due to a KCNQ2 mutation, the first such family to be described in the Korean population. The diagnosis of BFNC can be made based on clinical suspicion and careful history taking with special emphasis on the familial nature of the disorder. KCNQ2 mutations may be associated with BFNC in a number of different races, as has been reported in other ethnic groups.
Electroencephalography ; Epilepsy, Benign Neonatal/*diagnosis/genetics ; Female ; Humans ; Infant, Newborn ; KCNQ2 Potassium Channel/*genetics ; Magnetic Resonance Imaging ; Mutation ; Pedigree ; Republic of Korea ; Sequence Analysis, DNA

OBJECTIVETo study the protocol of construction of a KCNQ2-c.812G>T mutant and it's eukaryotic expression vector, the c.812G>T (p.G271V) mutation which was detected in a Chinese pedigree of benign familial infantile convulsions, and to examine the expression of mutant protein in human embyonic kidney (HEK) 293 cells.

METHODSA KCNQ2 mutation c.812G>T was engineered on KCNQ2 cDNAs cloned into pcDNA3.0 by sequence overlap extension PCR and restriction enzymes. HEK293 cells were co-transfected with pRK5-GFP and KCNQ2 plasmid (the wild type or mutant) using lipofectamine and then subjected to confocal microscopy. The transfected cells were immunostained to visualize the intracellular expression of the mutant molecules.

RESULTSDirect sequence analysis revealed a G to T transition at position 812. The c.812G>T mutation was correctly combined to eukaryotic expressive vector pcDNA3.0 and expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both the wild type and mutant molecules on the plasma membrane, which suggested that the c.812G>T mutation at the pore forming region of KCNQ2 channel did not impair normal protein expression in HEK293 cells.

CONCLUSIONSSuccessful construction of mutant KCNQ2 eukaryotic expression vector and expression of KCNQ2 protein in HEK293 cells provide a basis for further study on the functional effects of convulsion-causing KCNQ2 mutations and for understanding the molecular pathogenesis of epilepsy.

Epilepsy, Benign Neonatal ; genetics ; Fluorescent Antibody Technique ; Genetic Vectors ; HEK293 Cells ; Humans ; Infant, Newborn ; KCNQ2 Potassium Channel ; analysis ; genetics ; physiology ; Mutagenesis, Site-Directed ; Polymerase Chain Reaction