TABLE 1.

Clinical and diagnostic features of the RFC1 repeat expansion carriers

Patient ID	SCN 329	SCN 345	SCN 366	SCN 34	SCN 204	HNPP 398	SCN 179
Family history	No	No	No	No	No	No	No
Sex	F	F	M	F	F	F	M
AAO	50	50	58	51	46	69	55
AAE	60	70	63	68	56	72	65
DD	10	20	5	17	10	3	10
First symptoms	Instability	Instability	Instability (increased with closed eyes)	Instability	Instability (increased with closed eyes)	Tingling in hands and feet, instability	Instability (increased with closed eyes)
Cough	Yes	Yes	Yes	Yes	Yes	Yes	No
Gait ataxia	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Walk assistance	No	Yes (walker)	No	No	No	No	Yes
Limb ataxia	Yes	Yes	No	Yes	Yes	Yes	Yes
Dysarthria	Yes	Yes	No	No	Yes	No	Yes
Oculomotor findings	ISP, downbeat nystagmus	ISP, GEN	ISP	GEN	Normal	Normal	Normal
Vestibulopathy	Yes	Yes	N/A	N/A	N/A	N/A	N/A
Spasticity	No	No	No	No	No	No	No
DTR	Absent on the LL	Absent on the LL	Normal	Absent on the LL	Absent on the LL	Absent on the LL	Decreased on the LL
Extensor plantar response	No	No	No	No	No	No	No
Other	Distal hypo‐trophy, episodic diplopia	Head tremor, paraparesis, impaired vibration sense	N/A	Headache, impaired vibration sense	Dysphagia, impaired vibration sense	Head tremor, distal hypo‐trophia, impaired vibration sense, pes cavus, global muscle weakness	Dysphagia, incontinence, dystal hypo‐trophy and muscle weakness
MRI findings	Cerebellar atrophy	Cerebellar atrophy	Cerebellar atrophy	Cerebellar atrophy	Normal	Normal	Cerebellar atrophy
Neuropathy (NCS)	Yes	Yes	Yes	Yes	Yes	Yes	Yes

Abbreviation: AAO, age at onset (in years); AAE, age at examination (in years); DD, disease duration (in years); ISP, impaired smooth pursuit; DTR, deep tendon reflexes; GEN, gaze‐evoked nystagmus; LL, lower limbs; NA, not assessed; NCS, nerve conductions studies; MRI, magnetic resonance imaging; UL, upper limbs.