Table 1.

Clinical features of patients.

	Patient 1	Patient 2	Patient 3	Patient 4	Patient 5	Patient 6	Patient 7	Patient 8	Patient 9	Patient 10	Patient 11	Patient 12
Sex	Female	Female	Female	Male	Female	Female	Male	Female	Female	Male	Female	Male
Age	3y	3y 9m	5m	4y 2m	3y	5y	5y	died at 2y	3y	died at 2m	3y	2y 2m
Variants	c.553G>A p.A185Ta	c.643G>A p.G215Rb	c.712A>C p.I238La	c.794C>T A265Vc	c.829A>G p.T277Ad	c.853C>T p.P285Sd	c.868G>A; p.G290Se	c.901G>A; p.G301Sf	c.901G>A; p.G301Sf	c.1687G>A; p.D563Ng	c.1734G>A; p.M578Ih	c.1816A>T; p.K606Xa
Location	S3	S4-S5	S5	Pore loop	Pore loop	Pore loop	S6	S6	S6	C-term	C-term	C- truncating
Inheritance	De novo	De novo	De novo	De novo	De novo	De novo	De novo	De novo	De novo	De novo	De novo	De novo
Seizure onset	2d	14d	1d	2d	1d	1d	3d	1d	7d	1d	7d	3d
Seizure types	Tonic	Spasms, focal, GTCS	Focal, GTCS	Tonic, spams	Tonic, spasms, focal	Tonic, spasms, focal	Tonic	Tonic	Tonic	Tonic	Tonic, spams	Tonic
EEG	BUS	BUS->H	BUS	BUS->H	BUS->H	BUS->H	BUS	MS	BUS	MS	BUS->H	Normal
Diagnosis	OS	OS->IS	OS	OS->IS	OS->IS	OS->IS	OS	EIMFS	OS	EIMFS	OS->IS	SeLNE
ASMs used	PB, LEV	PB, TPM, LEV, VGB, OXC, ACTH, LEV, CZP, CLB, LCM	LEV, OXC	PB, VPA	LEV, PB, TPM, NZP, OXC, CLB, LCM, CBZ	PB, TPM, VPA, NZP, M	PB, TPM, OXC,	OXC, VPA	VPA, TPM, CZP, CBZ	PB, TPM, OXC, NZP	TPM, VPA, OXC	PB, LEV, TPM
Effective ASMs	LEV	LCM	OXC	VPA	OXC, LCM	/	OXC	OXC	CBZ, TPM	OXC	OXC	TPM
Seizure free	6 m	9 m	3 m	3 m	6 m	9 m	1.5 m	Died	5 m	Died	8 m	2 m
Developmental delay	Head control, eye contact walking, and no language	Poor eye contact, no head control, and hypotonia	Poor head Control and poor eye contact	No eye contact, no head control, difficulty in swallowing, and hypotonia	Poor head control, poor eye contact, unable to sit, and hypotonia	Head control, unable to sit, poor eye contact, and hypotonia	Poor head control, poor eye contact, unable to sit, and pyramidal signs	Died at 2 y due todysphagia and asphyxia	Poor eye contact, no head control, and hypotonia	Died at 2 m due to dysphagia and asphyxia	Head control, eye contact, walking, no language, and hypotonia	normal
Composite developmental Score*	6	2	/	1.5	2.5	3	2.5	/	1.5	/	5.5	10
Developmental ratings	Moderate	Profound	/	Profound	Profound	Severe	Profound	/	Profound	/	Moderate	Normal

^aMutations are new;

^bDalen Meurs-Van der Schoor et al., 2014;

^cWeckhuysen et al., 2012;

^dMiao et al., 2018;

^eMilh et al., 2013;

^fParrini et al., 2017;

^gMilh et al., 2015;

^hNumis et al., 2014. ACTH, adrenocorticotropic hormone; ASMs, antiseizure medications; BUS, burst-suppression; CBZ, carbamazepine; CLB, clobazam; CZP, clonazepam; EIMFS, epilepsy of infancy with migrating focal seizures; GTCS, generalized tonic–clonic seizure; H, hypsarrhythmia; IS, infantile spasms; LCM, lacosamide; LEV, levetiracetam; M, methylprednisolone; MS, Multiple spikes; NZP, nitrazepam; OS, Ohtahara syndrome; OXC, oxcarbazepine; PB, phenobarbital; SeLNE, Self-limited neonatal epilepsy; TPM, topiramate; VGB, vigabatrin; VPA, valproic acid. ^*According to STXBP1 composite developmental score (>3 y): mild ≥7, moderate: ≥5 and < 7, severe: ≥3 and < 5, and profound: < 3.