Among various genetic abnormalities, a point mutation of SNCA (synuclein, alpha [non-A4 component of amyloid precursor]), the gene coding for alpha-synuclein, was the first to be identified in 1997 in the so-called “Contursi family,” carrying an autosomic dominant inherited PD associated with an altered primary structure of alpha-synuclein [2]. This evidence concerns the gene SNCA and Parkinson disease.