Moreover, although CCKAR (779 T > C) or CCKBR (1550 G > A) gene polymorphisms alone were not related with visual hallucinations in PD patients in this study, the co-presence of a CCK −45 locus T allele and a CCKAR C allele was significantly associated with a greater risk of visual hallucinations [130]. This evidence concerns the gene CCKAR and Parkinson disease.