Table 2. Spectrophotometric MRC enzyme diagnostic data in skeletal muscle, liver and fibroblasts.

Patient liver and muscle samples. Data are expressed as activity relative to protein and as % CS ratio, which represents % of the normal control mean value when expressed relative to Citrate Synthase. Bold characters indicate clinically significant abnormal values (H–high, L–low). Complex I (CI), NADH-coenzyme Q1 oxidoreductase; Complex II (CII), succinate-coenzyme Q1 oxidoreductase; Complex III (CIII), decylbenzylquinol-cytochrome c oxidoreductase; Complex IV, cytochrome c oxidase (CIV).

	Enzyme Activity		% CS Ratio
Muscle	Patient	(Ref Range)	Patient	(Ref Range)
CI (nmol/min/mg)	18	19–72	18 L	36–269
CII (nmol/min/mg)	142 H	26–63	126	52–156
CIII (/min/mg)	13.1	12.8–50.9	17 L	62–185
CIV (/min/mg)	0.21 L	3.3–9.1	1 L	36–192
CS (nmol/min/mg)	320 H	85–179	-	-
Liver
CI (nmol/min/mg)	6	8–11	53	65–137
CII (nmol/min/mg)	116 H	54–73	158	59–127
CIII (/min/mg)	11.7	5.2–10.3	127	77–127
CIV (/min/mg)	0.05 L	0.5–0.9	6 L	75–134
CS (nmol/min/mg)	33	26–31	-	-