Table 3. Described Pedigrees with Core Disease Characteristics.

Descent	Genetics	Origin, # Family	Clinical Features			Electrophysiology				Structural		Additional Symptoms, Other Findings	Summary
			Tremor, Myoclonus	Seizures	Seizure Type	JLA	g-SEP	LLR	EEG	Imaging (cases)	PA (cases)
			Age at Onset (mean)
Asian	8q	Japanese, 57, 8	18–45 maj >30	?	GTC	+	+	+	G-PSW, PPR, PSW, PMR	atr (3) n.a. (>14)	n.d.	–	Classical phenotypeAge at onset at adulthoodInfrequent seizuresNo other neurological signsElectrophysiological abnormalities
	n.d.	Japanese, 3526–28,32,33,36,37,61,63–66	16–70 maj >25	17–54 maj >30	GTC, Ph	+	+	+	PSW, PPR, SW, Sp	atr (3)n.a. (25)inf (11)	n.a. (4)	Rare: nightblindness, behavioral arrest
	Excl 2p, 8q	Chinese, 12	5–?(34)	?	GTC, M	n.d.	n.d.	n.d.	M, SW, PSWSlow waves13/? presymptomatic changes detected	n.d.	n.d.	Schizophrenia in family	Classical phenotype with earlier age of onset in the youngest generations
European	2p	Italian, 71,4,6,9–11	11–50maj >20	12- 59maj >25	G, GTC, Ph, CP, M	+	+	+	Sp, SW, PPR, PMR, GPA, PSW, SW	atr (3)n.a. (27)	n.d.	Visuospatial impairment; Eyelid twitching; Voice tremor; Cognitive impairment;TMS cortical hyperexcitability, normal sensorimotor integration	Symptoms appear earlierComplex partial seizuresMild cognitive impairment
						Also in presymptomatic 3/711Absent in 1 pedigree11
	n.d.	Italian, 138	12–57	5–18	GTC, Abs	+	+	+	Sp, SW, PPR	atr (2)	n.d.	–
		Turkish, 135	29–?	30	GTC	n.d.	n.d.	n.d.	G-Sp, SW, PPR	n.a. (1)	n.d.	Migraine
	5p	French, 13, 15, 30	10–47 (30.8)	24–41(29.1)	GTC, Ph, CM, PS	+	+	+	Sp, PPR, PS	n.d.	n.d.	Progression in gait symptoms; Dysarthria; Ophthalmic migraine; sensitivity to exercise;GTC preceding M (5/16);	Later onsetNo cognitive impairmentGait disordersIndication of progression
	Excl 2p, 8q	Spanish, 15	30–60 (41)	30–67 (44.6)	GTC	+	+	+	G-PSW	n.a. (5)	n.d.	–	Childhood onsetPyramidal signsCerebellar dysfunctionFrequent seizuresCognitive impairmentProgression in symptoms
		Dutch, 114, 16, 17, 22, 23	12–45 (23.5)	13–44 (43)	GTC, M, Ph	–	+	+	SW, PPR	atr (2)n.a. (2)	+ (3)	TMS cortical hyperexcitability; nystagmus slight cognitive decline
		Italian, 113	3–12	23–34	GTC, CMPh	+	+	+	SW, PMR, Sp	n.d.	n.d	Prominent photic induced myoclonus and epilepsy; changing symptoms with age; Mild axial ataxia; behavioral disorder
		South African, 212Intermarriage between original inhabitants and European settlers	13–31 (20.9)	?	GTC	+	+	+	Abnormal background,PSW, Sp	atr (8)n.a. (2)	+ (1)	Frequent seizures; cognitive impairment; signs of pyramidal and cerebellar dysfunction, progression in symptoms

Abbreviations: Abs, absence; atr , atrophy; CM, cortical myoclonus; CP, complex partial; EEG, electroencephalography; excl, excluded; G, generalized; GPA, generalized paroxysmal activity; G-SEP, giant sensory evoked potential; GTC, generalized tonic-clonic; inf, infarct; JLA, jerk locked averaging; LLR, long latency reflex; maj, majority; M, myoclonic; n.a., no abnormalities; n.d., not done; PA, pathology; Ph, photosensitivity; PMR, photomyoclonic response; PPR, photoparoxysmal responses; PSW, polyspike-wave complexes; PS, partial seizures; Sp, spikes; SW, spike-wave complexes; TMS, transcranial magnetic stimulation.

+, abnormal; –, normal; # family, number of described families; ?, not known;