SCN2A mutations have been described in a very broad spectrum of clinical phenotypes including benign (familial) neonatal/infantile seizures and early infantile epileptic encephalopathies (EIEE) as Ohtahara syndrome (OS), Dravet syndrome (DS), epilepsy of infancy with migrating focal seizures and West syndrome (WS).
Mutations in SCN2A, the gene encoding α2 subunit of the neuronal sodium channel, are associated with a variety of epilepsies: benign familial neonatal-infantile seizures (BFNIS); genetic epilepsy with febrile seizures plus (GEFS+); Dravet syndrome (DS); and some intractable childhood epilepsies.
Mutations in the neuronal voltage-gated sodium channel genes SCN1A and SCN2A are associated with inherited epilepsies, including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (severe myoclonic epilepsy of infancy).
Mutations in the SCN1A and SCN2A genes are reported in childhood epilepsies; in particular SCN1A was found mutated in patients with Dravet syndrome and with generalized epilepsy with febrile seizures plus (GEFS+).
The band 2q24 constitutes the smallest commonly deleted segment in these patients, and contains the voltage-gated sodium channel genes SCN1A and SCN2A, associated with Dravet syndrome and benign familial neonatal-infantile seizures, respectively.
We performed mutational analyses on SCN2A in 116 patients with severe myoclonic epilepsy in infancy, infantile spasms, and other types of intractable childhood partial and generalized epilepsies and did whole-cell patch-clamp recordings on Na(v)1.2 channels containing identified mutations.
Mutations in SCN1A and SCN2A are responsible for several dominant idiopathic epilepsy disorders, including generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy of infancy (SMEI).
These channelopathies include genes encoding voltage-gated channels specific for sodium (SCN1A, SCN2A, SCN1B, SCN9A) and potassium (KCNQ2, KCNQ3) which account for a variety of epilepsy phenotypes ranging from mild, such as Benign familial neonatal seizures (BFNS) to severe, such as Dravet syndrome (severe myoclonic epilepsy of infancy, SMEI) and the rare and unusual syndrome paroxysmal extreme pain disorder (PEPD).
Mutations of voltage-gated sodium channel genes SCN1A, SCN2A, and SCN1B have been identified in several types of epilepsies including generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy in infancy (SMEI).