Our profiling analysis revealed that within the analysed dopaminergic neurons isolated complex I (NDUFA13) deficiency was rarely detected in PD neurons and most complex I decreased neurons harboured multiple OxPhos deficiencies (Fig. 5c), whilst for POLG neurons the most common isolated OxPhos deficiency was complex I (91.30% vs. 1.58%, PD). The gene discussed is NDUFA13; the disease is Parkinson disease.