Article

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

Department of Neurology, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense C, Denmark.
Epilepsy Research (impact factor: 2.29). 55(1-2):137-46. pp.137-46
Source: PubMed

ABSTRACT 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). A total of 214 twin pairs with epileptic seizures and 190 pairs with epilepsy were ascertained. Significantly higher concordance rates were found for monozygotic (MZ) compared to dizygotic (DZ) twins for both epileptic seizures (0.56 for MZ and 0.21 for DZ pairs, P<0.001) and for epilepsy (0.49 for MZ and 0.16 for DZ pairs, P<0.001). Concordance rates were also higher for MZ twins compared to DZ twins for both generalized epilepsy (0.65 for MZ and 0.12 for DZ) and for localization-related epilepsy (0.30 for MZ and 0.10 for DZ). In twin pairs where both members had seizures, 83% of MZ and 65% of DZ pairs had the same major epilepsy syndrome. Genetic factors were found to account for 80% of the liability to both epileptic seizures and epilepsy. In conclusion, analysis of this neurologist-verified epilepsy twin data set has confirmed that genetic factors have a substantial impact on the etiology of epileptic seizures as well as on the occurrence of both generalized and partial epilepsies.

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    Article: Genetic causes of epilepsy.
    Rocío Sánchez-Carpintero Abad, Francesc X Sanmartí Vilaplana, José María Serratosa Fernández
    [show abstract] [hide abstract]
    ABSTRACT: The contribution of genetic factors to the origin of different epilepsies is a fact established by epidemiological, clinical, and molecular studies. These studies have made it possible to identify numerous mutations in different genes that cause or predispose to the development of certain types of epilepsy. The study of single-gene epilepsies has contributed relevant data regarding the pathophysiology of epilepsy. Most of these genes encode voltage- or ligand-gated ion channels. Other single-gene epilepsies are related to mutations that provoke alterations in neuronal maturation and migration during embryonic development. Nevertheless, the most common forms of epilepsy are not caused by single mutations but by a combination of polymorphisms, most of which are unknown, that generate an alteration in neuronal excitability. In some syndromes, genetic alterations and their consequences have made it possible to explain the therapeutic response to different drugs. Therefore, the progress being made in genetics is changing the classification and diagnosis of epilepsy; moreover, it can sometimes influence the choice of treatment. The advances made in genetic knowledge of epilepsy have led to the description of new epilepsy syndromes and to a better characterization of known ones. However, the genes responsible for the most common forms of idiopathic epilepsy remain mostly unknown. This means that for the time being, in clinical practice, genetic diagnosis is limited to uncommon syndromes and to cases in which treatment decisions or genetic counseling can be derived from the diagnosis.
    The Neurologist 12/2007; 13(6 Suppl 1):S47-51. · 1.26 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

214 twin pairs
 
classification systems
 
DZ pairs
 
DZ twins
 
epilepsy syndromes
 
epileptic seizures
 
etiology
 
generalized epilepsy
 
Genetic factors
 
higher concordance rates
 
localization-related epilepsy
 
major epilepsy syndrome
 
monozygotic
 
MZ twins
 
neurologist-verified epilepsy twin data
 
neurologists
 
population-based Danish Twin Registry
 
substantial impact
 
twin pairs
 
twins recruited