OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with genetic epilepsy with febrile seizures plus (GEFS+). METHODS: Clinical data of the proband and his family members were collected. Following extraction of genomic DNA, the proband was subjected to high-throughput sequencing. Candidate variant was verified by Sanger sequencing of the proband and other family members. RESULTS: The pedigree, including 6 patients with febrile seizures from 3 generations, was diagnosed with typical GEFS+. Among them, 2 had febrile seizures (FS), 1 had febrile seizures plus (FS+), and 3 had febrile seizures with focal seizures. High-throughput sequencing revealed that the proband has carried a heterozygous missense variant of c.4522T>A (p.Tyr1508Asn) of the SCN1A gene. Sanger sequencing confirmed that other five patients and one normal member from the pedigree have also carried the same variant, which yielded a penetrance of 85.7%. CONCLUSION The c.4522T>A (p.Tyr1508Asn) of the SCN1A gene probably underlay the disease in this pedigree. The pattern of inheritance was consistent with autosomal dominant inheritance with incomplete penetrance. Above finding has enriched the variant spectrum of the SCN1A gene.
Epilepsy/genetics* ; Humans ; NAV1.1 Voltage-Gated Sodium Channel/genetics* ; Pedigree ; Phenotype ; Seizures, Febrile/genetics*

Febrile seizures are the most common nervous system disease in childhood, and most children have a good prognosis. However, some epilepsy cases are easily induced by fever and are characterized by "fever sensitivity", and it is difficult to differentiate such cases from febrile seizures. Epilepsy related to fever sensitivity includes hereditary epilepsy with febrile seizures plus, Dravet syndrome, and
Cadherins/genetics* ; Child ; Epilepsy/genetics* ; Epileptic Syndromes ; Humans ; Mutation ; Seizures, Febrile/genetics*

OBJECTIVE: To explore the genetic basis for a girl with febrile convulsion as the main manifestation. METHODS: The child was subjected to whole exome sequencing (WES) and copy number variation sequencing(CNV-seq). Fluorescence quantitative PCR was carried out to validate the microdeletion in her family. RESULTS: The 7-year-old girl was diagnosed with febrile convulsion (complex type) for having fever for 3 days, mild cough and low thermal convulsion once. Her father, mother and aunt also had a history of febrile convulsion. A heterozygous deletion with a size of approximately 1.5 Mb was detected in the 16p13.11 region by WES and CNV-seq. The deletion has derived from her father and was confirmed by fluorescence quantitative PCR. CONCLUSION 16p13.11 microdeletion syndrome has significant clinical heterogeneity. Different from those with epilepsy, mental retardation, autism, multiple malformations, carriers of 16p13.11 deletion may only manifest with febrile convulsion. Deletion of certain gene(s) from the region may be related to febrile convulsion and underlay the symptom of this child.
Child ; DNA Copy Number Variations ; Epilepsy ; Female ; Humans ; Seizures/genetics* ; Seizures, Febrile/genetics* ; Whole Exome Sequencing

Child ; Developmental Disabilities/genetics* ; Frameshift Mutation ; Humans ; Seizures/genetics* ; Seizures, Febrile/genetics* ; Semaphorins/genetics*

Channelopathies are a heterogeneous group of disorders resulting from the dysfunction of ion channels located in the membranes of all cells and many cellular organelles. These include diseases of the nervous system (e.g., generalized epilepsy with febrile seizures plus, familial hemiplegic migraine, episodic ataxia, and hyperkalemic and hypokalemic periodic paralysis), the cardiovascular system (e.g., long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia), the respiratory system (e.g., cystic fibrosis), the endocrine system (e.g., neonatal diabetes mellitus, familial hyperinsulinemic hypoglycemia, thyrotoxic hypokalemic periodic paralysis, and familial hyperaldosteronism), the urinary system (e.g., Bartter syndrome, nephrogenic diabetes insipidus, autosomal-dominant polycystic kidney disease, and hypomagnesemia with secondary hypocalcemia), and the immune system (e.g., myasthenia gravis, neuromyelitis optica, Isaac syndrome, and anti-NMDA [N-methyl-D-aspartate] receptor encephalitis). The field of channelopathies is expanding rapidly, as is the utility of molecular-genetic and electrophysiological studies. This review provides a brief overview and update of channelopathies, with a focus on recent advances in the pathophysiological mechanisms that may help clinicians better understand, diagnose, and develop treatments for these diseases.
Ataxia ; Bartter Syndrome ; Brugada Syndrome ; Cardiovascular System ; Channelopathies* ; Diabetes Insipidus, Nephrogenic ; Diabetes Mellitus ; Endocrine System ; Epilepsy, Generalized ; Genetics ; Hypoglycemia ; Hypokalemic Periodic Paralysis ; Immune System ; Ion Channels ; Isaacs Syndrome ; Long QT Syndrome ; Membranes ; Migraine with Aura ; Myasthenia Gravis ; Nervous System ; Neuromyelitis Optica ; Organelles ; Polycystic Kidney Diseases ; Respiratory System ; Seizures, Febrile

OBJECTIVEDespite substantial research efforts worldwide, the role of inflammatory cytokine IL-1β in the onset of febrile seizures (FS) remains controversial. The aim of this study was to assess the relationship between rs16944 polymorphism of the IL-1β-511T gene and occurrence of simple FS in a sample of Han children in northern China.

METHODSThe IL-1β-511T gene rs16944 was genotyped by SNaPshot SNP technique in 141 FS children and 130 healthy control subjects. The genotypic and allelic frequencies in the two groups were comparatively analyzed.

RESULTSThere were no significant differences in genotypic and allelic frequencies of rs16944 polymorphism of the IL-1β-511T gene between FS patients and control subjects (P>0.05).When the clinical data on A/A, A/G and G/G genotypes of the rs16944 polymorphism in FS patients, there was statistically significant difference in age of first onset (χ(2)=19.491, P<0.01), temperature of first onset (χ(2)=9.317, P<0.05) and family history of FS (χ(2)=26.798, P<0.01).

CONCLUSIONSThere is no association between rs16944 polymorphism of the IL-1β-511T gene and the incidence of FS in Han children in Northern China. However, the differences in genotypes of this polymorphism might be associated with pathogenesis and prognosis of simple FS in the population studied.

Child, Preschool ; China ; ethnology ; Female ; Humans ; Infant ; Interleukin-1beta ; genetics ; Male ; Polymorphism, Single Nucleotide ; Seizures, Febrile ; genetics

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

METHODData 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. Genomic DNA was extracted from peripheral blood samples with standard protocol. Mutations in PRRT2 were screened using PCR amplification and Sanger sequencing.

RESULTTwenty-nine BFIE families were recruited in this study. In total, 110 family members were affected. The age of seizure onset of these affected members was between 2 and 12 months (median: 4.5 months). All probands presented with clusters of seizures. Two probands had one seizure induced by diarrhea respectively at 25 months and 31 months. In four BFIE families, four family members had a history of febrile seizures. PRRT2 mutations were found in 17 of the 29 (58.6%) BFIE families. Mutation c.649_650insC was detected in 12 of the 17 families with PRRT2 mutations. Mutation c.649delC (p.R217EfsX12) was identified in three families. Mutation c.323_324delCA (p. T108SfsX25) and c.904_ 905insG (p. D302GfsX39) were detected in one family, respectively.

CONCLUSIONThe minimum seizure onset age of affected members in BFIE families was 2 months of age. The seizures often occur in clusters. PRRT2 is the major causative gene of BFIE in Chinese families. Mutation c.649_650insC is the hotspot mutation of PRRT2. A novel mutation c.323_324delCA was first reported in BFIE family. Few affected members with PRRT2 mutation presented with febrile seizures phenotype.

Age of Onset ; Asian Continental Ancestry Group ; genetics ; DNA Mutational Analysis ; Epilepsy, Benign Neonatal ; genetics ; Humans ; Infant ; Membrane Proteins ; genetics ; Mutation ; genetics ; Nerve Tissue Proteins ; genetics ; Phenotype ; Seizures ; Seizures, Febrile

Brain Diseases ; epidemiology ; etiology ; Child ; Child Development Disorders, Pervasive ; epidemiology ; etiology ; Child, Preschool ; Epilepsies, Myoclonic ; epidemiology ; etiology ; genetics ; Epilepsy ; epidemiology ; etiology ; Humans ; Infant ; Risk Factors ; Seizures, Febrile ; epidemiology ; etiology ; Vaccination ; adverse effects

OBJECTIVETo summarize the phenotypes and identify SCN1A mutations in families with generalized epilepsy with febrile seizures plus (GEFS(+)), and analyze the genotype- phenotype correlations in GEFS(+) families.

METHODGenomic DNA was extracted from peripheral blood lymphocytes of the proband and other available members in the GEFS(+) families. The phenotypes of the affected members were analyzed. The coding regions and flanking intronic regions of the SCN1A gene were screened for mutations using PCR and direct DNA sequencing.

RESULTIn 39 GEFS(+) families, there were 196 affected members, ranging from 2 to 22 affected members in each family. Their phenotypes included febrile seizures (FS) in 92(46.9%), febrile seizures plus (FS(+)) in 62(31.6%), FS or FS(+) with partial seizures in 12(6.1%), afebrile generalized tonic-clonic seizures (AGTCS) in 11(5.6%), myoclonic atonic epilepsy in 8(4.1%), Dravet syndrome in 2(1.0%), childhood absence epilepsy in 1 (0.5%), FS(+) with myoclonic seizures in 1(0.5%), AGTCS and myoclonic seizures in 1 (0.5%), partial seizures in 1 (0.5%), unclassified seizures in 5 (2.6%). Four families were found with SCN1A mutations, including three families with missense mutation (N935H, R101Q, G1382R) and one family with truncation mutation (C373fsx378). In three families with missense mutations, the phenotypes include FS, FS(+), FS(+) with partial seizures, and AGTCS. In one family with truncation mutation, the phenotypes included FS, FS(+), and Dravet syndrome. The mother of proband in the family with missense mutation (R101Q) and the father of proband in the family with truncation mutation (C373fsx378) were both somatic mosaicism. Both of their phenotypes were FS(+).

CONCLUSIONThe most common phenotypes of GEFS(+) were FS and FS(+), followed by the FS/FS(+) with partial seizures and AGTCS. The most severe phenotype was Dravet syndrome. SCN1A mutation rate in GEFS(+) was about 10%. Missense mutation was common in GEFS(+) families, few with truncation mutation. Few members of GEFS(+) families had somatic mosaicism of SCN1A mutations and their phenotypes were relatively mild.

Base Sequence ; Child, Preschool ; DNA Mutational Analysis ; Epilepsies, Myoclonic ; genetics ; Epilepsy, Generalized ; genetics ; Female ; Genotype ; Humans ; Infant ; Male ; Molecular Sequence Data ; Mutation ; genetics ; Mutation, Missense ; NAV1.1 Voltage-Gated Sodium Channel ; genetics ; Pedigree ; Phenotype ; Seizures, Febrile ; genetics

OBJECTIVETo study the clinical and genetic characteristics of generalized epilepsy with febrile seizures plus (GEFS).

METHODSData of two probands of the disease were collected through outpatient clinic. DNA was extracted from peripheral blood leukocytes using RelaxGene Blood DNA System. Twenty-six exons of SCN1A were amplified by polymerase chain reaction (PCR), the PCR products were screened by denaturing high performance liquid chromatography (DHPLC), then the abnormal fragments were sequenced by Sanger method in order to find the mutations of SCNIA gene.

RESULTS(1) There were 28 affected individuals in the two families of GEFS+ (14 males and 14 females). Febrile seizures (FS) were present in 7 cases, febrile seizures plus (FS+) in 6 cases, FS+ and absence seizures in 1 case, FS+ and myoclonic seizures in 1 case, uncertain type in 13 cases. No severe phenotype was seen. Bilineal inheritance occured in one GEFS+ family. (2) A samesense mutation (c. 1212A > G) of SCN1A gene was found in the proband and an unaffected individual of pedigree B of GEFS.

CONCLUSIONS(1) GEFS+ is a syndrome with the characteristics of heterogeneous clinical phenotypes; bilineal inheritance suggests the possibility of complex inheritance with additive gene effects. (2) Our study failed to provide evidence supporting a causal relation between the SCN1A mutation and the etiologic gene in the GEFS+ family B, which indicates that GEFS+ has the phenotypic and genotypic heterogeneity.

Adolescent ; Child ; Child, Preschool ; DNA Mutational Analysis ; Epilepsy, Generalized ; complications ; genetics ; Female ; Genetic Testing ; Genotype ; Humans ; Infant ; Male ; NAV1.1 Voltage-Gated Sodium Channel ; Nerve Tissue Proteins ; genetics ; Pedigree ; Phenotype ; Seizures, Febrile ; complications ; genetics ; Sodium Channels ; genetics