SNCA and Parkinson disease: Several risk factors were identified including disease-causing mutations in a specific set of genes that mediate the autosomal-dominant or autosomal-recessive forms of PD [3], among which mutations in alpha synuclein (SNCA) and in leucine-rich repeat kinase 2 (LRRK2) are responsible for autosomal-dominant PD forms whereas mutations in parkin, PTEN-induced putative kinase 1 (PINK1), DJ-1, and ATP13A2 are accountable for PD that displays an autosomal recessive mode of inheritance [3].