PRKN and Parkinson disease: The two non-manifesting individuals carrying a heterozygous PRKN variant, and the homozygous PRKN-PD patient showed a trend towards a decreased basal OCR level compared to the control group (controls 0.73 ± 0.1 vs. 0.55 ± 0.1 vs. 0.45 ± 0.17; p = 0.48, p = 0.29) (Fig. 3c).