The detection of G4C2 expansions in the C9orf72 gene was observed in both familial and sporadic FTLD and ALS cases, with a higher prevalence in ALS-FTLD.106-108 Novel mutations and prevalent genetic variations included novel GRN mutations in FTLD cases and significant associations of GRN and MAPT mutations with familial FTLD.109 Genetic variations associated with Parkinson’s disease across ethnic and geographical groups included the recessive model of rs35479735, the variable prevalence of LRRK2 p.G2019S (European ancestry), and risk stratifications of NR4A2, GBA, and MTHFR variations. Here, LRRK2 is linked to amyotrophic lateral sclerosis.