Table 1.

Clinical Features of Individuals with a GNAO1 Mutation

	Individual 1	Individual 2	Individual 3	Individual 4
Gender	female	female	female	female
Age	13 years	4 years, 1 month	died at 11 months	8 years
Mutation	c.836T>A (p.Ile279Asn)	c.521A>G (p.Asp174Gly)	c.572_592 del (p.Thr191_Phe197 del)	c.607G>A (p.Gly203Arg)
Inheritance	de novo	de novo, somatic mosaic	de novo	de novo
Diagnosis	Ohtahara syndrome	Ohtahara syndrome	Ohtahara syndrome	epileptic encephalopathy
Initial symptom	tonic seizure at 4 days	series of tonic seizures at 29 days (tonic upgaze, head nodding, extension of all extremities)	series of tonic seizures at 2 weeks (resemble spasms)	opisthotonic posture, developmental delay at 7 months
Initial EEG	suppression-burst pattern at 4 days	suppression-burst pattern at 29 days	suppression-burst pattern at 2 weeks	diffuse irregular spike-and-slow-wave complex at 5 years
Course of seizures	tonic seizure at 5 years	series of tonic seizures at 9 months	tonic seizure at 10 months	focal seizure (tonic upgaze), tonic seizure at 5 years
Course of EEG	multifocal sharp waves at 1 year, 4 months; suppression-burst pattern at 5 years, 6 months	hypsarrhythmia at 3 months; diffuse spike-and-slow-wave complex at 1 year, 7 months; sharp waves at frontal lobe at 3 years, 9 months	hypsarrhythmia at 4 months	not done
Involuntary movement	-	-	dystonia	severe chorea, athetosis
Seizure control	intractable (2–3 times per day)	intractable (0–2 times per day)	intractable	intractable (several times per day)
Development
Head control	-	+	-	-
Sitting	-	-	-	-
Meaningful words	-	-	-	-
MRI	normal at 1 month; cerebral atrophy at 5 years, 6 months	delayed myelination and thin corpus callosum at 10 months	normal at 3 months	delayed myelination at 1 year, 3 months; reduced cerebral white matter, thin corpus callosum at 4 years, 8 months