Table 1.

SACS mutations detected in French Canadian and Tunisian patients. “hm” means mutation carried the homozygous form, “c het” means mutation had compound heterozygous allele. “rs” means respectively.

Mutation	Exon	Domain	AOO	Clinical Symptoms	Neurological Changes	Population (Ethnicity)	Refs.
c.6594delT (I2949Ffs*4,) or c.5254C > T (p.Q1752X), hm or c-het	10	SIRPT1 + SIRPT3 rs	12–18 mths	ataxia neurotrophy learning disability mental dysfunctions foot deformities	cerebellar loss of Purkinje cells cortical degeneration	Canada (French Canadian)	[5,38]
several variants, c.8844delT (p.I2949FfsX2952): most common, hm or c-het	8 or 10	SIRPT1, 2 or 3, XPBC or DNAJ	NA	NA	NA		[42]
c.9284dupC 9p.Ala3096Cysfs*2), hm	10	SIRPT3	early child- hood	clumsy gait uncoordinated hand movement mild non-progressive dysarthria intermittent dysphagia pes cavus	atrophy of cerebellar vermis		[41]
c.10046G > C (p.A3324P), hm	10	Between SIRPT3 and XPBC	2–4 yrs	ataxia gait dysfunctions spasticity	cerebellar syndrome cerebellar dysarthria no myelinated nerve fibers	Tunisian (Tunisian)	[43]
c.1411delT, hm	8	SIRPT1	5 yrs	ataxia gait dysfunctions
c.1155insA, hm	8	SIRPT1	1–9 yrs	ataxia gait dysfunctions pyramidal syndrome
c.3662T > C (p.W1196R), hm	10	SIRPT1	10–14 yrs	ataxia gait dysfunctions
c.12846_12850delAGAG, hm	10	Between XPBC and DNAJ	1–3 yrs	spastic gait ataxia dysarthria unsteadiness	horizontal nystagmus neuropathy no retinal hypermyelination		[44]
c.2439-2440delAT(V815Gfs*4), hm	10	SIRPT1	13–19 yrs	ataxia nystagmus	no loss of large myelinated fibers		[45]