Absence of mutations in major GEFS+ genes in myoclonic astatic epilepsy.
Myoclonic astatic epilepsy (MAE) is a genetically determined condition of childhood onset characterized by multiple generalized types of seizures including myoclonic astatic seizures, generalized spike waves and cognitive deterioration. This condition has been reported in a few patients in generalized epilepsy with febrile seizures plus (GEFS+) families and MAE has been considered, like severe myoclonic epilepsy of infancy (SMEI), to be a severe phenotype within the GEFS+ spectrum. Four genes have been identified in GEFS+ families, but only three (SCN1A, SCNlB, GABRG2) were found in MAE patients within GEFS+ families. We analysed these three genes in a series of 22 sporadic patients with MAE and found no causal mutations. These findings suggest that MAE, unlike SMEI, is not genetically related to GEFS+. Although MAE and SMEI share the same types of seizures, only SMEI patients are sensitive to fever. This is probably its main link to GEFS+. A different family of genes is likely to account for MAE.
Nabbout
R
R
Département de Neuropédiatrie, Hôpital Saint Vincent-de-Paul, AP-HP, 82 Avenue Denfert Rochereau, 75014 Paris, France. rimanabbout@yahoo.com
Kozlovski
A
A
Gennaro
E
E
Bahi-Buisson
N
N
Zara
F
F
Chiron
C
C
Bianchi
A
A
Brice
A
A
Leguern
E
E
Dulac
O
O
D002675:Child, Preschool; D004247:DNA / Q000235:genetics; D004831:Epilepsies, Myoclonic / Q000235:genetics*; D004829:Epilepsy, Generalized / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D003294:Seizures, Febrile / Q000235:genetics*; D015222:Sodium Channels / Q000235:genetics; D062547:Voltage-Gated Sodium Channel beta-1 Subunit; D020663:ras Guanine Nucleotide Exchange Factors / Q000235:genetics*
D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins; C568242:SCN1A protein, human; C470379:SCN1B protein, human; D015222:Sodium Channels; D062547:Voltage-Gated Sodium Channel beta-1 Subunit; D020663:ras Guanine Nucleotide Exchange Factors; D004247:DNA