The alpha4-subunit gene of the neuronal nicotinic acetylcholine receptor (CHRNA4) has been identified as the first gene underlying an idiopathic partial epilepsy syndrome in human autosomal-dominant nocturnal frontal lobe epilepsy.
Certain mutations in specific parts of the neuronal nicotinic acetylcholine receptor (nAChR) subunit genes CHRNA4, CHRNB2, and probably CHRNA2, can cause autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE).
The involvement of all genes coding for brain-expressed nAChR subunits, with known chromosome localization ( CHRNB2, 1q21; CHRNA2, 8p21; CHRNA6, CHRNB3, 8p11.2; CHRNA7, 15q14; CHRNA5/A3/B4, 15q24 and CHRNA4, 20q13.2) was investigated in four unrelated ADNFLE Italian families for at least three generations.
In order to assess the genetic defects in NFLE, we performed a mutation screening in 33 unrelated patients with sporadic NFLE by amplifying and sequencing bidirectionally TM 1-3 of CHRNA4, CHRNB2 and CHRNA2 which contain the mutations reported in ADNFLE.
Mutations of the gene encoding the neuronal nicotinic acetylcholine receptor alpha 4 subunit (CHRNA4 ) have been found in ADNFLE-ENFL1 families, but these mutations account for only a small proportion of ADNFLE cases.
The clinical courses of patients with deletions of both KCNQ2 and CHRNA4 were those of typical BFNS, and none presented with the phenotype of autosomal dominant nocturnal frontal lobe epilepsy, some of which are caused by mutations of CHRNA4.
It is therefore reasonable to hypothesize that at least another gene not belonging to the nAChR gene family, in addition to CRH, is involved in the pathogenesis of ADNFLE.
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE; MIM 600513) has been associated with mutations in the genes coding for the alfa-4 (CHRNA4), beta-2 (CHRNB2), and alpha-2 (CHRNA2) subunits of the neuronal nicotinic acetylcholine receptor (nAChR) and for the corticotropin-releasing hormone (CRH).
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a rare familial seizure disorder caused by mutations in at least two different subunit genes of the neuronal nicotinic acetylcholine receptor (nAChR), CHRNA4 and CHRNB2.
To describe the clinical features of a family from Northern Norway in which autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is associated with a Ser248Phe amino acid exchange in the second transmembrane domain of the neuronal nicotinic acetylcholine receptor alpha4 subunit (CHRNA4).
A missense mutation in the neuronal nicotinic acetylcholine receptor alpha 4 subunit is associated with autosomal dominant nocturnal frontal lobe epilepsy.
A pattern is emerging of site-specific mutation within the second transmembrane domain of CHRNA4 in association with autosomal dominant nocturnal frontal lobe epilepsy and sporadic nocturnal frontal lobe epilepsy in families with different ethnic backgrounds.
Mutations in neuronal nAChRs are found in a rare form of familial nocturnal frontal lobe epilepsy (ADNFLE), while mutations in the neuromuscular subtype of the nAChR are responsible for either congenital myasthenia syndromes (adult subtype of neuromuscular nAChR) or a form of arthrogryposis multiplex congenita type Escobar (fetal subtype of neuromuscular nAChR).
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is known to be caused by mutations in the transmembrane regions of the neuronal nicotinic acetylcholine receptor (nAChR) genes CHRNA4 and CHRNB2.
Autosomal dominant nocturnal frontal lobe epilepsy: a genotypic comparative study of Japanese and Korean families carrying the CHRNA4Ser284Leu mutation.
We also tested the hypothesis that the 2-bp deletion polymorphism in the partially duplicated α7 nAChR gene may be related to ADNFLE in these patients.
Based on genetic studies in patients with epileptic disorders worldwide and animal models of seizure, it has been demonstrated that nAChR activity is altered in some specific types of epilepsy, including autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and juvenile myoclonic epilepsy (JME).