PCDH8 and Parkinson disease: Based on their characteristic physiological roles 12 genes (BSN, DCLK1, KCNQ2, NCAM1, NEDD4L, PAK1, PCDH8, STXBP1, SYN1, UBE2N, UNC13A and VAMP2) colored in blue in Figure 4 were classified as potentially involved in Parkinson's disease.