Table 1.

Clinical characteristics of LOF and GOF variants and phenotypic subgroups

	BFIE	IE	DEE	GE	NDDwoE	LOF	GOF
n	15	33	177	20	20	34	136
Percentage with epilepsy	100%	100%	100%	100%	0%	68%	100%
Median age at seizure onset	6 months	5 months	3 months	42 months	–	24 months	4 months
Most common seizure types	Focal, focal to bilateral TC and bilateral TC	Focal, bilateral TC and tonic	Bilateral TC, focal and tonic	Absences, bilateral TC and febrile seizures	–	Absence seizures, bilateral TC and myoclonic seizures	Bilateral TC, tonic and focal seizures
Phenotype subgroups	–	–	–	–	–	GE 41% NDDwoE 32% DEE 9% UE 18%	BFIE 7% IE 10% DEE 53% UE 30%
Cognition	Normal 100%	Normal 33% Mild ID 52% Moderate ID 15%	Moderate ID 22% Severe ID 73% Unknown 5%	Normal 20% Mild ID 30% Moderate ID 35% Severe ID 10% Unknown 5%	Normal 10% Mild ID 45% Moderate ID 20% Severe ID 15% Unknown 10%	Normal 15% Mild ID 36% Moderate ID 15% Severe ID 21% Unknown 15%	Normal 11% Mild ID 9% Moderate ID 15% Severe ID 39% Unknown 26%
Comorbidities	Paroxysmal kinesigenic dyskinesia	Language delay, behavioural issues	Hypotonia, CVI, ataxia	Language delay, behavioural issues	Behavioural disorders (ASD, ADHD), delayed speech, microcephaly	Language delay, ASD, behavioural issues, ataxia	Hypotonia, CVI, dyskinesia, ataxia
Mortality	0%	0%	10.2%	0%	0%	0%	9.0%
Precision medicine	SCBs	SCBs	SCBs				SCBs

ADHD = attention-deficit hyperactivity disorder; bilateral TCs = bilateral tonic-clonic seizures; CVI = cortical vision impairment; GE = generalized epilepsy; IE = intermediate epilepsy; UE = unclassifiable epilepsy.