Finally, hypomethylation of intron 1 of the α-synuclein (SNCA) gene was found more frequently in 78 iRBD patients than in 74 controls, being hypomethylation at cytosine-phosphate-guanine 17 associated with increased risk for clinical phenoconversion to neurodegenerative diseases and at cytosine-phosphate-guanine 14, 15, and 16 with disease progression [143]. Here, SNCA is linked to neurodegenerative disease.