Interestingly, different neuropathological reports have shown an absence of Lewy pathology in most patients with familiar forms of parkin-related PD and in a proportion of PD patients with mutations in the LRRK2 gene, which are respectively the most common cause of recessive and dominant forms of PD, and a small proportion of sporadic PD cases (Kalia and Lang, 2015; Tolosa et al., 2020). Here, LRRK2 is linked to Parkinson disease.