Table 1. Respiratory chain enzyme activities in skin fibroblasts and fresh muscle tissue of the index patient.

Complex	Patient fibroblasts	Control range	Patient fresh muscle	Control range
I	30	104–206a	5	70–250b
II	NM	—	119	67–177b
III	1428	1270–2620a	1490	2200–6610b
IV	1026	684–1190c	1067	810–3120b

Abbreviation: NM, not measured.

Deficiencies are indicated in bold.

^amU/U Cytochrome c oxidase.

^cmU/U Citrate synthase.

^bmU/mU Citrate synthase.