Mutations in some genes, including SNCA, LRRK2 and GBA, have been found to be risk factors for "sporadic" (non-familial) PD.[1] Mutations in the gene LRRK2 are the most common known cause of familial and sporadic PD, accounting for approximately 5% of individuals with a family history of the disease and 3% of sporadic cases.[70][64] A mutation in GBA presents the greatest genetic risk of developing Parkinsons disease.[71]