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).
Variants in the SCN2A gene cause a broad spectrum of epilepsy syndromes of variable severity including benign neonatal-infantile epilepsy (BFNIE), developmental and epileptic encephalopathies (DEE), and other neuropsychiatric disorders.
Thirty-three families fulfilled clinical criteria for benign familial neonatal epilepsy (BFNE); 27 of these families had KCNQ2 mutations, one had a KCNQ3 mutation, and two had SCN2A mutations.
Heterozygous mutations in the genes KCNQ2 and SCN2A cause the two other autosomal dominant seizure disorders of infancy: benign familial neonatal epilepsy and benign familial neonatal-infantile epilepsy.
Missense mutations in SCN2A, encoding the brain sodium channel NaV 1.2, have been described in benign familial neonatal-infantile seizures (BFNIS), a self-limiting disorder, whereas several SCN2A de novo nonsense mutations have been found in patients with more severe phenotypes including epileptic encephalopathy.
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.
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 identified two novel SCN2A mutations causing benign familial neonatal-infantile seizures and analysed the functional consequences of these mutations in a neonatal and an adult splice variant of the human Na(+) channel Na(V)1.2 expressed heterologously in tsA201 cells together with beta1 and beta2 subunits.
Mutations in SCN2A, encoding the brain sodium channel Na(V)1.2, have previously been reported to be associated with benign familial neonatal infantile seizures, febrile seizures plus, and intractable epilepsy of infancy.
Mutations of the gene encoding the alpha2 subunit of the neuronal sodium channel, SCN2A, have been found in benign familial neonatal-infantile seizures (BFNIS).
Mutations in SCN2A, the gene encoding the brain voltage-gated sodium channel alpha-subunit Na(V)1.2, are associated with inherited epilepsies including benign familial neonatal-infantile seizures (BFNIS).
The known loci for benign familial neonatal/infantile seizures (BFNS/BFNIS), generalized epilepsy with febrile seizures plus (GEFS+) and the BFIS locus on chromosome 19q were excluded.
Mutations in the voltage-gated sodium channel alpha2 subunit (SCN2A) gene on chromosome 2 were recently identified in families affected by neonatal and infantile seizures (benign familial neonatal-infantile seizures, BFNIS) with typical onset before 4 months of life.
Here, we describe a clinically intermediate variant, benign familial neonatal-infantile seizures, with mutations in the sodium-channel subunit gene SCN2A.