Novel frameshift mutation in the SACS gene causing spastic ataxia of charlevoix-saguenay in a consanguineous family from the Arabian Peninsula: A case report and review of literature

Table 1 Nerve conduction studies of proband II-3

Nerve stimulated	Stimulation site	Recording site	Latency (ms)			Amplitude; motor = mV; sensory = μV			Conduction; velocity (m/s)			Minimum; F-Wave; latency (ms)
			NL	RT	LT	NL	LT	RT	NL	LT	RT	NL	LT	RT
Median (m)	Wrist	APB	8.5	7.0	≤ 4.3	2.6	2.7	≥ 4	23	27	≥ 49	NR	NR	≤ 31
	ACF	APB	18.2	16.3		2.4	2.0
Ulnar (m)	Wrist	ADM	5.0	4.0	≤ 3.3	1.6	2.4	≥ 6	29	33	≥ 49	NR	NR	≤ 32
	BE	ADM	12.8	10.5		1.5	2.4		24	31
	AE	ADM	17.5	15.1		1.5	2.1
Median (s)	Wrist	2nd digit	NR	NR	≤ 3.4			≥ 20			≥ 50
Ulnar (s)	Wrist	5th digit	NR	NR	≤ 3.1			≥ 17			≥ 50
Peroneal (m)	Ankle	EDB	NR	NR	≤ 6.4			≥ 2			≥ 44	NR	NR	≤ 56
	BF	EDB
	LPF	EDB
Peroneal (m)	BF	TA	3.6	4.0	≤ 6.6	1.3	2.3	≥ 3	25	23	≥ 44
	LPF	TA	6.8	7.1		1.0	2.1
Tibial (m)	Ankle	AHB	NR	NR	≤ 5.8			≥ 4			≥ 41	NR	NR	≤ 56
	PF	AHB
Peroneal (s)	LC	Ankle	NR	NR	≤ 4.4			≥ 7			≥ 40
Sural (s)	Calf	PA	NR	NR	≤ 4.4			≥ 7			≥ 40
H-reflex	Absent bilaterally

All sensory latencies are peak latencies. All sensory nerve conduction velocities are calculated using onset latencies. “m” means motor study; “s” means sensory study. RT: Right; LT: Left; NL: Normal; NR: No response; APB: Abductor pollicis brevis; ADM: Abductor digiti-minimi; EDB: Extensor digitorum brevis; TA: Tibialis anterior; AHB: Abductor hallucis brevis; ACF: Antecubital fossa; BE: Below elbow; AE: Above elbow; BF: Below fibula; LPF: Lateral popliteal fossa; PF: Popliteal fossa; LC: Lateral calf; PA: Posterior ankle.

Table 2 Needle electromyography of proband II-3

Items	Insertionalactivity	Spontaneous activity		Voluntary motor unit action potentials
		Fibrillation potentials	Fasciculation potentials	Amplitude	Duration	Polyphasia	Recruitment	Activation
LT MG	↑	+1	0	+2	+2	+2	↓↓	NL
LT TA	↑	+2	0	+2	+1	+2	↓↓	NL
LT VL	NL	0	0	NL	NL	NL	NL	NL
LT ADM	↑	+1	0	+1	+1	+2	↓↓↓	NL

↑ means increased; ↓↓ means moderately reduced; ↓↓↓ means severely reduced; NL: Normal; LT: Left; MG: Medial gastrocnemius; TA: Tibialis anterior; VL: Vastus lateralis; ADM: Abductor digiti minimi.