Table.

Respiratory chain complex activities in the patient’s skeletal muscle and lymphoblastoid cell line

	Mean specific activity			Ratio
Complex	CI	CIV	CS	I/CS	IV/CS
Skeletal muscle
Patient	26	1,351	563	0.046	2.4
Controls (n = 25), mean ± SD	106 ± 46	1,583 ± 370	685 ± 157	0.15 ± 0.03	2.3 ± 0.01
Lymphoblasts
Patient	20	1,276	612	0.032	2.1
Controls (n = 8), mean ± SD	50 ± 18	1,432 ± 343	669 ± 174	0.074 ± 0.06	2.1 ± 0.04

Complex I (CI) and IV (CIV) enzyme activities were normalized by citrate synthase (CS), a matrix enzyme. Patient activities were compared to control values for muscle and lymphoblast mitochondria. Specific enzymes activities as nmol of substrate/min/mg of mitochondrial protein.