Localization of idiopathic generalized epilepsy on chromosome 6p in families of juvenile myoclonic epilepsy patients.
Juvenile myoclonic epilepsy (JME) is a distinct subform of idiopathic generalized epilepsy of adolescence. Linkage studies with Bf and serologic HLA markers in families of JME patients have shown a tight linkage on chromosome 6. We present a linkage analysis with HLA-DQ restriction fragment length polymorphisms on more extended families, paying particular attention to the epilepsy type of the affected family members. We studied 21 families of JME patients with a total of 143 family members and obtained a highest logarithm of the odds (lod) score of 3.9 (theta m = 0.01, theta f = 0.01) assuming a dominant mode of inheritance and 70% penetrance when family members with JME, absence epilepsy, or epilepsy with generalized tonic-clonic seizures (GTCS) were considered as affected. When we also classified clinically normal family members with generalized spike-wave discharges in the EEG as "affected," the maximum lod score was 4.1 (theta m = 0.01, theta f = 0.3) under a dominant mode of inheritance and 90% penetrance. These findings support the conclusion that a gene locus for a group of idiopathic generalized epilepsies (JME, epilepsy with absences, and epilepsy with GTCS) maps to chromosome 6p.
Department of Neurology, Klinikum Rudolf Virchow, Free University of Berlin, Germany.
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M
Durner
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T
Sander
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Greenberg
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Johnson
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Beck-Mannagetta
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Janz
D002896:Chromosomes, Human, Pair 6; D004831:Epilepsies, Myoclonic / Q000235:genetics*; D004827:Epilepsy / Q000235:genetics*; D008040:Genetic Linkage; D006683:HLA-DQ Antigens / Q000235:genetics; D006801:Humans; D008126:Lod Score; D010375:Pedigree
D006683:HLA-DQ Antigens