LRRK2 and Parkinson disease: Voxel-based morphometry (VBM) was used to examine structural changes in N = 10 PD patients with mutations in the LRRK2 gene, N = 10 LRRK2-non-manifesting carriers (NMC), N = 24 sPD, and N = 12 non-manifesting non-carrier (NMNC) healthy individuals.