Table 2.

Cytochrome C Oxidase Activity in Patient Heart and Fibroblasts

Sample	COX/CS Activitya	% Control
Heart:
Control	5.6 ± 3.2 (n = 6)	100
Patient N	0.4	7
Fibroblasts:
Control	.82 ± .21 (n = 16)	100
Control	.89 ± .18 (n = 5)	100
Patient N	.24 ± .11 (n = 6)	28
Patient N + COX15	.51 ± .14 (n = 5)	61

^aCOX and citrate synthase (CS) were measured as described in the “Material and Methods” section. The number in parentheses indicates the number of independent measurements.