Phenotype and frequency of STUB1 mutations: next-generation screenings in Caucasian ataxia and spastic paraplegia cohorts

Table 2 Clinical, MRI and lab findings of STUB1 mutation carriers

Subject	STUB1 mutation	Gender	Age at investigation [years]	Age at onset ataxia [years]	Tendon reflexes	Spasticity	Babinski reflex	Ankle clonus	Urge incontince	Hypogonadism	Cognitive impairment
18161	p.Leu123Val	M	16	2	Normal	-	-	-	+	-	-
91078	p.Met240Thr	F	21	16	Normal	-	-	-	+	-	-
25130_01	p.Ala79Thr; Ala79Asp	M	46	29	Increased	Lower limb, mild	-	+ bilateral	-	-	-
25130_10	.p.Ala79Thr; Ala79Asp	M	50	49	Increased	Lower limb. moderate	-	+ bilateral	+	-	-

Subject	SDFS	SARA	SPRS	Nerve conduction studies		Motor evoked potentials	MRI	Hormones	Testicular volume (sonography)
Subject	SDFS	SARA	SPRS	Sensory	Motor	Motor evoked potentials	MRI	Hormones	Testicular volume (sonography)
18161	3	10	n.a.	Sural nerve: normal	Tibial nerve: normal	Prolonged CMCT to LE (18 ms)	Atrophy cerebellum and parietal cortex	Testosteron normal (236 ng/dl)	25 ml, each side
								Estradiol normal (8,4 pg/ml
								LH normal (3,6 IU/l)
								FSH normal (0,7 IU/l)
91078	4	12	n.a.	Sural nerve: no SNAP	Tibial nerve: normal	Prolonged CMCT to UE (10 ms), not evoked to LE	Atrophy cerebellum	Estradiol normal (50 pg/ml)	n.a.
								LH normal (8.3 mE/ml)
								FSH normal (3.7 mE/ml)
25130_01	6	n.d.	38	n.d.	n.d.	Normal	Atrophy cerebellum	Testosteron (4.3 ng/ml)	n.d.
								Estradiol normal (22 pg/ml9
								LH normal (9.6 mU/l)
								FSH normal (16.0 mU/ml)
25130_10	3	14.5	5	n.d.	n.d.	Normal	Atrophy cerebellum	n.d.	n.d.

Legend: m, male; f, female; n.a., not applicable, n.d., not done; SARA, scale for the Assessment and Rating of Ataxia, reaching from 0 to 40, with higher scores indicating more severe ataxia [9]; scores < 3 points are considered unspecific. SPRS, spastic paraplegia rating scale, reaching from 0 to 52, with higher scores indicating more severe spastic paraplegia [10] (please note, however, that several items of the SPRS scale increase also with more severe ataxia); CMCT: Central motor conduction time. Reference values CMCT lower extremity (LE) < 16.0 ms; CMCT upper extremity (UE) < 9 ms. LE, lower extremity; UE, upper extremity; LH, luteinizing hormone; FSH, follicle-stimulating hormone; SNAP, sensory nerve action potential; MRI, magnetic resonance imaging. SDFS, Spinocerebellar degeneration functional score. This score was used to evaluate the disability stage from 1 to 7 (0: no functional handicap; 1: no functional handicap but signs at examination; 2: mild, able to run, walking unlimited; 3: moderate, unable to run, limited walking without help; 4: severe, walking with one stick; 5: walking with two sticks; 6: unable to walk, requiring wheelchair; 7: confined to the bed).

ISSN: 1750-1172