Unsurprisingly, heteroplasmic variation in the DLOOP accounted for a large proportion of differential variation in both cases and controls, a phenomenon reported in similar studies (Supplementary Fig. 3) (Williams et al., 2013), and MTATP8, MTND4L, and MTDN4 appear well-conserved in both PD cases and controls, an indication of mutational intolerance in these particular subunits and again similar to published data. This evidence concerns the gene MT-ND4L and Parkinson disease.