PINK1 and Parkinson disease: First, Pink1–/– rats have construct validity for the recessively inherited loss of function Pink1 mutations that are the second most common mutation among autosomal recessive forms of PD; these mutations are also causally linked to early onset familial cases of PD (Valente et al., 2004; Kumazawa et al., 2008; Scarffe et al., 2014).