Similarly, the 17q21.31 locus, which is a 970 kb region of high linkage disequilibrium (LD) encoding two distinct haplotypes (H1 and H2) and encompassing the MAPT gene (Figure 1A), has been genetically associated with several primary tauopathies, as well as PD (Höglinger et al., 2011; Kouri et al., 2015; Jun et al., 2016; Bandres-Ciga et al., 2019; Nalls et al., 2019). This evidence concerns the gene MAPT and Parkinson disease.