Developed in collaboration with The Michael J. Fox Foundation, this model contains a knockin of the A53T-mutated SNCA gene deeming the rat SNCA gene non-functional. The knockin contains humanized amino acids for the region spanning amino acids 53-122. The resulting model expresses a humanized A53T alpha-synuclein protein without endogenous rat alpha-synuclein. This model was generated using CRISPR/Cas9 genome targeting strategies. The A53T mutation in the SNCA gene has been linked to early-onset Parkinson’s disease (PD), making this model useful for understanding alpha-synuclein biology and PD pathogenesis.