Key numbers Number of reported Genes 202 Number of Records 2391 Number of countries / regions 81 Number of Literature reports 576 Top 10 genes with most references Gene No. of Reports No. of Ethnic groups No. of literature LRRK2 327 54 86 PARK2 362 33 74 SNCA 137 24 55 CYP2D6 67 18 33 PINK1 115 19 23 MAPT 56 17 22 UCHL1 49 12 19 MAOB 36 8 16 PARK7 59 12 16 APOE 19 8 14 Top 10 genes with most variants Gene No. of variants PARK2 165 LRRK2 83 PINK1 71 SNCA 50 LRRK1 34 PARK7 30 HTRA2 24 MT-ND1 23 MT-ND5 20 MT-ND2 18 UCHL1 18 Top 10 genes with most negative reports Gene No. of negative reports LRRK2 110 SNCA 64 PARK2 55 CYP2D6 44 PINK1 35 UCHL1 35 MAOB 27 MAPT 25 MAOA 24 NOS2A 23 Top 10 countries/regions with most research done Country No. of literature US 123 Germany 58 Japan 46 Chinese (Taiwan) 36 Italy 36 UK 31 Spain 29 Chinese (China) 27 France 23 Australia 21