Although the frequency of NAT2*4 is not as common among Caucasians (which is the group analyzed in our study), this association may still be similar to the MAPT H1 haplotype association with PSP (i.e. MAPT H1 is associated with increased PSP risk, but is also very common in the general population with a frequency of 0.78) [6]. This evidence concerns the gene NAT2 and supranuclear palsy, progressive, 1.