Table 1.

OXPHOS enzymes activity measurements and substrate oxidation in muscle of the reported patient with VARS2 deficiency.

Enzyme	mUnit/mg/ protein	N	mUnit/mUnit CS	N	mUnit/mUnit Complex II	N
Citrate synthase (CS)	198	150–338			3,02↓	3,06–5,47
Complex I	12↓	28–76	0,06↓	0,14–0,35	0,18↓	0,46–1,07
Complex I + III	80	49–218	0,41	0,24–0,81	1,22	0,93–2,84
Complex II (CII)	66	33–102	0,33	0,18–0,41
Complex II + III	171	65–180	0,86↑	0,3–0,67	2,61↑	1,36–2,49
Complex III	611	304–896	3,09	1,45–3,76	9,32	5,94–12,91
Cytochrome c oxidase	193	181–593	0,97	0,91–2,24	2,94↓	4,19–12,05
Complex V	248	86–257	1,25	0,42–1,25	3,78	1,68–3,96
Pyruvate dehydrogenase	20,6	5,3–19,8	0,104↑	0,026–0,079	0,314	0,107–0,315
Substrate oxidation	nmol/h/mUnit CS	N	mUnit/mUnit CS	N	nmol/h/mUnit Complex II	N
[1-14C]Pyruvate+Malate	600	263–900	3,03	1,54–3,55	9,15	3,57–11,97
[1-14C]Pyruvate+Carnitine	948↑	302–856	4,79↑	1,65–3,66	14,45↑	4,48–14,24
[1-14C]Pyruvate+Malate-ADP	119↑	32–102	0,60↑	0,21–0,41	1,82	0,69–1,88
[1-14C]Pyruvate+Malate+ CCCP	803	304–889	4,05↑	1,31–3,11	12,24	3,55–12,35
[1-14C]Pyruvate+Malate+Atracyloside	134↑	19–90	0,68↑	0,16–0,55	3,24	1,17–3,61
[U-14C]Malate+Pyruvate+Malonate	509	282–874	2,57	1,56–3,87	7,75	3,69–12,53
[U-14C]Malate+Acetylcarn.+Malonate	517	273–678	2,61	1,16–2,82	7,89	3,8–11,44
[U-14C]Malate+ Acetylcarn.+Arsenite	301	156–378	1,52	0,57–1,52	4,58	2,17–6,14
[U-14C]Glutamate+Acetylcarnitine	162	86–209	0,82	0,35–1,06	2,48	1,4–5,11

N, normal range; CS, citrate synthase, protein concentration of the patient muscle 600 × g homogenate: 1.64 mg/ml. Values in bold show abnormal values. Arrow down: reduced values compared to healthy controls. Arrow up: increased values compared to healthy controls.