Along with the sporadic form of PD caused by wild type αS, a missense point mutation in the snca gene results in the more aggregation prone mutant αSAla53Thr (αSA53T), which has been found to be associated with a familial form of PD (Polymeropoulos et al., 1997; Narhi et al., 1999; Li et al., 2001; Papadimitriou et al., 2016). Here, SNCA is linked to Parkinson disease.