Table 1.

Seven of the 131 patients had identified KCNQ2mutatoins. The clinical and familial histories are summarized

Patient number	Patient 1	Patient 2	Patient 3	Patient 4	Patient 5	Patient 6	Patient 7
Genotype	c.1627 G>A	c.1294 C>T	c.387+1 G>T	c.740 C>T	c.1741 C>T	c.853 C>A	c.860 C>T
Protein change	p.(Val543Met)	p.(Arg432Cys)	Splicing	p.(Ser247Leu)	(p.Arg581*)	p.(Pro285Thr)	p.(Thr287Ile)
Family mutation	Father and two aunts	Father	Mother	De novo	Mother and sister	De novo	De novo
Sex	Female	Female	Male	Male	Female	Female	Male
Other genetic study	KCNQ3	Panel	KCNQ3	Whole exon	Panel	Whole exon	KCNQ3
Family number of seizures other than index patient (n)	3	1	1	0	2	0	0
Later seizures older than 3 years from familial KCNQ2 mutation (n)	0	2	0	1	1	1	1
Age at first seizure	Day 14	1 year (febrile seizure)	Day 3	Day 3	Day 3	Day 2	Newborn
Seizure type	General tonic	General tonic	General clonic	General tonic	General tonic	General tonic	General tonic
Seizure frequency before drug control	+	+	+++	+++	+++	+++	+++
Drug control	OXC	OXC, TOP	PB, OXC	Intravenous PB, PHT then changed to PB, SAB, CLN	PB	Intravenous PB, PHT then changed to oral PB, SAB, CLN, OXC	TOP, OXC
Seizure frequency after 6‐months drugs	‐	‐	‐	‐	‐	‐	+
Abnormal MRI	No	No	No	Basal ganglion	No	Thin corpus callosum	No
Dev. Del./Int. Dis.	No	Mild(ADHD)	No	Severe	No	Severe	Severe

The sequence data of each patient were checked against the GenBank reference sequence and version number of KCNQ2 gene (NM_172107.3).

Abbreviations: NA, not available; VOUS, variance of unknown significance; PHT, phenytoin; OXC, oxcarbazepine; VPA, valproic acid; TOP, topiramate; PB, phenobarbital; KEP, levetiracetam; SAB, vigabatrin; CLN, clonazepam; MRI, magnetic resonance imaging; EEG, electroencephalography; +++, daily; ++, weekly; +, less than weekly; ADHD, attention deficit and hyperactivity; Dev. Del./Int. Dis., Developmental delay/intellectual disability.