Mutations in the GABRG2 gene cause a spectrum of seizure disorders, ranging from early-onset isolated febrile seizures (FS) to childhood absence epilepsy (CAE) to generalized epilepsy with febrile seizures plus, type 3 (GEFS+3), which tends to represent a more severe phenotype. Patients with isolated febrile seizures usually have onset in the first year of life and show spontaneous remission by age 6 years. Many of these patients may later develop absence seizures, which may also spontaneously remit, whereas a few may continue to have various types of febrile and afebrile seizures that persist beyond childhood, consistent with GEFS+. There is phenotypic variability in the seizure type, even within a family carrying the same mutation, suggesting that other loci may be involved (summary by Singh et al., 1999 and Marini et al., 2003).
For a phenotypic description and a discussion of genetic heterogeneity of familial febrile seizures, see 121210.
For a general phenotypic description and a discussion of genetic heterogeneity of GEFS+, see 604233.
For a phenotypic description and discussion of genetic heterogeneity of childhood absence epilepsy, see 600131. [from
OMIM]