The study will be performed in a double-blind, randomized, and placebo-controlled parallel group manner.<h4>Methods</h4>PD patients will be specifically identified and assigned to treatment groups stratified by their genetic "mitochondrial risk burden" and consequently expected mitochondrial dysfunction and treatment response to coenzyme Q10 (homozygous or compound heterozygous <i>Parkin/PINK1</i> mutation carriers [P++], heterozygous <i>Parkin/PINK1</i> mutation carriers [P+], "omics" positive [omics+], and "omics" negative PD patients [omics-]). Here, PRKN is linked to Parkinson disease.