Genome wide high density SNP-based linkage analysis of childhood absence epilepsy identifies a susceptibility locus on chromosome 3p23-p14.

Childhood absence epilepsy (CAE) is an idiopathic generalised epilepsy (IGE) characterised by typical absence seizures manifested by transitory loss of awareness with 2.5-4 Hz spike-wave complexes on ictal EEG. A genetic component to the aetiology is well recognised but the mechanism of inheritance and the genes involved are yet to be fully established.

The accuracy of self-reported history of seizures in Danish, Norwegian and U.S. twins.

Questionnaire surveys provide an efficient means of identifying potential seizure cases in large population-based cohorts. Concerns exist, however, with regard to the reliability of self-reported information both with respect to the validity of the results obtained and with regard to the usefulness of this approach in identifying true cases. Information on history of seizures obtained by questionnaire from members of 47,626 twin pairs included in the Mid-Atlantic (MATR), Danish (DTR) and Norwegian (NTR) Twin Registries was verified using medical records and detailed clinical and family interviews.

Linkage and mutational analysis of CLCN2 in childhood absence epilepsy.

In order to assess the chloride channel gene CLCN2 as a candidate susceptibility gene for childhood absence epilepsy, parametric and non-parametric linkage analysis was performed in 65 nuclear pedigrees. This provided suggestive evidence for linkage with heterogeneity: NPL score=2.3, p<0.

Linkage and association analysis of CACNG3 in childhood absence epilepsy.

Childhood absence epilepsy (CAE) is an idiopathic generalised epilepsy characterised by absence seizures manifested by transitory loss of awareness with 2.5-4 Hz spike-wave complexes on ictal EEG. A genetic component to aetiology is established but the mechanism of inheritance and the genes involved are not fully defined.

Evaluation of CACNA1H in European patients with childhood absence epilepsy.

CACNA1H was evaluated in a resource of Caucasian European patients with childhood absence epilepsy by linkage analysis and typing of sequence variants previously identified in Chinese patients. Linkage analysis of 44 pedigrees provided no evidence for a locus in the CACNA1H region and none of the Chinese variants were found in 220 unrelated patients.

Gender differences in epilepsy.

Purpose: The aim of this study was to look at gender differences in unselected populations of patients with epilepsy classified according to the 1989 International League Against Epilepsy (ILAE) criteria.

Methods: Data were obtained from two sources: (a) the EpiBase database at the outpatient clinic at the Department of Neurology, Aarhus University Hospital, Denmark, confined to adults with epilepsy (n=2,170), and (b) the Danish Twin Registry (n=318).

Results: In localization-related epilepsy, no overall gender difference was found in either the EpiBase population (n=1,511; w=750 (50%), m=761 (50%); p=0.

Genetic factors in seizures: a population-based study of 47,626 US, Norwegian and Danish twin pairs.

The purpose of the study was to describe a large sample of twins reporting a history of seizures, to characterize seizures in the three subpopulations, and to estimate the relative importance of genetic and environmental factors in seizure occurrence. Seizure history was determined by questionnaires completed by twins in population-based twin registries in the United States, Norway and Denmark. Concordance rates were calculated for all seizure categories within and across twin populations.

Which seizure-precipitating factors do patients with epilepsy most frequently report?

When treating patients with epilepsy, dealing with seizure-precipitating factors is a partly neglected and underestimated supplement to more traditional therapies. The aim of this study was to investigate the incidence of seizure precipitants in a large epilepsy population and to determine which precipitants patients most often reported. Study participants included twins and their family members ascertained from the Norwegian Twin Panel (NTP), the Danish Twin Registry (DTR), and the Mid-Atlantic Twin Registry (MATR).

Epileptic seizures and syndromes in twins: the importance of genetic factors.

The role of genetic factors in the occurrence of epilepsy syndromes was studied in twins recruited from the population-based Danish Twin Registry. A total of 34,076 twins were screened for epilepsy. Cases were confirmed and classified by two neurologists according to the classification systems of the International League Against Epilepsy (ILAE).

Genetic and environmental factors in febrile seizures: a Danish population-based twin study.

The relative importance of genetic and environmental factors in the etiology of febrile seizures was estimated using a large, unselected population-based twin sample. A total of 34,076 twins (aged 12-41 years), recruited from the Danish Twin Registry, were screened for febrile seizures by questionnaire. Information was obtained from 11,872 complete pairs.

Evaluation of the positional candidate gene CHRNA7 at the juvenile myoclonic epilepsy locus (EJM2) on chromosome 15q13-14.

A previous study of 34 nuclear pedigrees segregating juvenile myoclonic epilepsy (JME) gave significant evidence of linkage with heterogeneity to marker loci on chromosome 15q13-14 close to the candidate gene CHRNA7 (Hum. Mol. Genet.