Although these findings run contrary to the conventional hypothesis that lower SNCA expression confers PD-protection, it might be that rs356219, rs365165, or any other SNP in the 3′ LD block (extended to include intron 4), exerts a regulatory effect not simply by changing total SNCA-mRNA levels but by a different molecular mechanism, such as splicing, to change the relative levels of the different splice forms (e.g., NACP140/112). Here, SNCA is linked to Parkinson disease.