Fig. 3.

Oxygen consumption study.

Oxygen consumption rate (OCR) was evaluated in cultured skin fibroblasts from proband 1 and compared to an intra-run control. OCR was normalized over citrate synthase activity (CS). Cultured skin fibroblasts of proband 1 showed a significant decrease of oxygen consumption as compared to the control during the entire run (A). The spare respiratory capacity, calculated by subtracting the basal OCR from the maximal OCR (third measurement after addition of FCCP), is significantly different between the proband 1 (0.21 ± 0.03) and intra-run control (1.34 ± 0.12) (B). The spare respiratory capacity is also significantly decreased in cultured skin fibroblasts of proband 1 when compared to a small set of inter-run controls (n = 10, 1.17 ± 0.33).