Additional mutations in the PSEN1 gene including p.G217D, p.V272A, and p.L420R have been associated with dementia and parkinsonism (Takao et al., 2002; Jimenez-Escrig et al., 2004; Puschmann et al., 2009; Niwa et al., 2013). Here, PSEN1 is linked to Parkinson disease.