Table 1

Clinical features of the patients with IFIH1 variants

Case no.	IFIH1 variants (NM_022168.4)	Origin	Sex	FS onset age	aFS onset age	Seizure course	EEG	Brain CT/MRI	ASM	DD	Seizure free duration	Diagnosis
1	c.2906G>T/p.Gly969Val	De novo	M	Infant	Infant	FS twice; atypical absence seizures 1–2 times per week	Diffuse discharges	Normal	LCM	Speech delay	1 year	EFS+
2	c.2966T>A/p.Val989Glu	De novo	M	Toddler	Preschooler	FS, 2–3 times/year; GTCS, once	Generalised SW	Normal	VPA, CNZ	Normal	4 years	EFS+
3	c.263G>A/p.Ser88Asn	Paternal	F	Infant	Infant	FS, once (after vaccination), GTCS, 3 times during 1 month	Normal	Normal	VPA	Normal	2.5 years	GE
3	c.1046A>G/p.Lys349Arg	Maternal	F	Infant	Infant	FS, once (after vaccination), GTCS, 3 times during 1 month	Normal	Normal	VPA	Normal	2.5 years	GE
4	c.1709T>G/p.Met570Arg	Paternal	M	Toddler	Toddler	FS, once; spasm 1–2 times per day	Interictal: generalised SW/PSW; ictal: spasms	Normal	VPA	Normal	1 year	EFS+
4	c.2366C>T/p.Thr789Ile	Maternal	M	Toddler	Toddler	FS, once; spasm 1–2 times per day	Interictal: generalised SW/PSW; ictal: spasms	Normal	VPA	Normal	1 year	EFS+
5	c.2069T>C/p.Leu690Pro	Paternal	F	Preschooler	Teenager	FS, once; GTCS twice during 13 years	generalised SW	Normal	LTG, PER	Normal	2 years	EFS+
5	c.2232T>A/p.Phe744Leu	Maternal	F	Preschooler	Teenager	FS, once; GTCS twice during 13 years	generalised SW	Normal	LTG, PER	Normal	2 years	EFS+

aFS, afebrile seizures; ASM, antiseizure medication; CNZ, clonazepam; DD, developmental disorder; EFS+, epilepsy with febrile seizures plus; F, female; FS, febrile seizures; GE, generalised epilepsy; GTCS, generalised tonic-clonic seizure; LCM, lacosamide; LTG, lamotrigine; M, male; PER, perampanel; PSW, poly spike-and-slow waves; SW, spike-and-slow waves; VPA, valproate.