Benign Febrile Seizures

What are benign febrile seizures

Benign febrile seizures (convulsions) are an inherited predisposition to developing a tonic clonic seizure with a high fever.

The description is limited to convulsions associated with high fever in children younger than the age of 5 years (usually between 6 and 36 months of age), with no cause for the seizure other than the fever.

Benign febrile seizures are common, occurring in 3% to 5% of children younger than the age of 5 years. Most patients have only one or two seizures.

Recent genetic analysis of families with febrile convulsions has defined specific associated gene defects

Genetic Epilepsies with Generalized Seizures

Epilepsy Syndrome	Gene	Gene Product	Inh ∗	Testing
Neonates—Infants	Benign familial neonatal epilepsy	KCNQ2 / KCNQ3	K + channel subunits Kv7.2-Kv7.3	AD	Sequencing, deletion/duplication analysis
Benign familial neonatal/infantile epilepsy	SCN2A	Na + channel subunit Nav1.2	Sequencing
Benign familial infantile epilepsy	PRRT2	Proline-rich transmembrane protein 2	Sequencing
ATP1A2	Na + /K + transporting ATPase
Early infantile epileptic encephalopathy with suppression-burst (Ohtahara syndrome)	ARX	Aristaless-related homeobox	XLD	Sequencing, deletion/duplication analysis
CDKL5	Cyclin-dependent kinase-like 5
STXBP1	Syntaxin binding protein 1	AD
KCNQ2	Potassium channel subunit Kv7.2
PLB1	Phospholipase B1	AR
Familial infantile myoclonic epilepsy	TBC1D24	TBC1 domain family, member 24	AR	Sequencing (commercially unavailable in United States)
Generalized epilepsy with febrile seizures plus (GEFS+)	SCN1B	Voltage-gated Na + channel, type 1β	AD	Sequencing
SCN1A	Voltage-gated Na + channel, Nav1.1	Sequencing, deletion/duplication analysis
GABRG2	GABA A receptor, γ2 subunit	?	Sequencing
SCN2A	Na + channel subunit Nav1.2	AD
GABRD	GABA A receptor, δ subunit	?
Severe myoclonic epilepsy of infancy (Dravet syndrome)	SCN1A	Voltage-gated Na + channel, Nav1.1	AD	Sequencing, deletion/duplication analysis
SCN2A	Na + channel subunit Nav1.2	Sequencing
GABRG2	GABA A receptor, γ2 subunit	?
Generalized	Childhood absence epilepsy	GABRG2	GABA A receptor, γ2 subunit	?	Sequencing
GABRA1	GABA A receptor, α1 subunit	AD
SLC2A1	Solute carrier family 2, member 1	AD/AR
GABRB3	GABA A receptor, β3 subunit	?
CACNA1H	T-type Ca ++ channel, α1H subunit
CACNG3	Ca ++ channel subunit γ3
LGI4	Leucine-rich repeat LGI family, member 4	AR
Juvenile absence epilepsy	ME2	Mitochondrial malic enzyme 2	AR	Commercially unavailable
INHA	Inhibin α	?
Juvenile myoclonic epilepsy	GABRA1	GABA A receptor, α1 subunit	AD	Sequencing
EFHC1	EF-hand domain (C-terminal) containing 1	?
BRD2	Bromodomain containing 2
CACNB4	Ca ++ channel subunit β4
Myoclonic-atonic epilepsy (myoclonic epilepsy of Doose)	SCN1A	Voltage-gated Na + channel, Nav1.1	AD	Sequencing, CNV † analysis
SCN2A	Na + channel subunit Nav1.2	Sequencing
GABRG2	GABA A receptor, γ2 subunit	?	Sequencing
SLC2A1	Solute carrier family 2, member 1	AD/AR	Sequencing, CNV analysis
Focal	Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE)	CHRNA4	Nicotinic Ach receptor, α4 subunit	AD	Sequence analysis
CHRNB2	Nicotinic Ach receptor, β2 subunit
CHRNA2	Nicotinic Ach receptor, α2 subunit
Autosomal dominant epilepsy with auditory features (ADEAF)	LGI1	Leucine-rich repeat LGI family, member 1
Benign epilepsy with centrotemporal spikes (BECTS)	ELP4	Elongator acetyltransferase complex, subunit 4	?	Commercially unavailable
Other described genes include (gene products unknown): (4q13.2-q21.3), (7p21.3), (1q25 and 18q, digenic), (12q22-23.3)	?	Genes unknown

∗ Inheritance: AD , Autosomal dominant; XLD , X-linked dominant; AR , autosomal recessive; CNV, Copy Number Variant.