Table 1. Characteristics of individuals in study.

Mild group	Sex	Diagnosis	IQ	motor delay	Mutation	exon affected	Seizure onset age (months)	No. months between seizure onset and last assessment
M1	M	DS border	61	N	microdel	1~16	6	261
M2	M	GEFS+	50–75	N	nonsense	16	6	189
M3	F	DS	70–85	N	nonsense	1	15	180
M4	F	DS	50–70	N	splicing	intron 5	5	190
M5	M	DS	59	Y	frameshift	16	8	187
M6	F	FS+	66	N	frameshift	23	8	187
M7	F	DS	65	Y	frameshift	16	7	188
M8	M	DS	50	Y	frameshift	16	6	189
M9	M	DS border	81	N	nonsense	2	7	104
Severe group								No. months between seizure onset and severe diagnosis
S1	F	DS	<24	N	frameshift	20	6	44
S2	M	DS	<24	Y	frameshift	10	4	39
S3	F	DS	<24	Y	frameshift	2	6	43
S4	F	DS	<24	Y	frameshift	1	6	41
S5	M	DS	<24	Y	nonsense	5	9	48
S6	F	DS	<24	Y	frameshift	11	5	45
S7	M	Epilepsy/ID	<24	Y	microdel	1~26	2	59
S8	F	DS	<24	Y	frameshift	10	6	61
S9	M	DS	<24	Y	nonsense	19	2	40
S10	F	DS	<24	Y	nonsense	24	8	47
S11	F	DS	<24	Y	nonsense	17	2	70
S12	F	DS	<24	Y	microdel	1~26	6	138

DS, Dravet syndrome; GEFS+, genetic epilepsy with febrile seizures plus; F, female; M, male.