Analyses of sequence variants within the SIRT1 gene promoter regions in PD patients revealed the existence of three heterozygous sequence variants (g.69644133C>G, g.69644213G>A, and g.69644351G>A), suggesting that polymorphisms may alter the transcription factor sites of SIRT1 gene promoter resulting in decreased SIRT1 levels and increased PD risk [145]. This evidence concerns the gene SIRT1 and Parkinson disease.