The G2019S mutation in leucine-rich repeat kinase 2 (<i>LRRK2</i>) is a prevalent cause of late-onset Parkinson's disease, producing psychiatric and motor symptoms, including depression, that are indistinguishable from sporadic cases.
G2019S carriers do not manifest changes in gray matter volume or diffusivity parameters in Parkinson's disease-related structures prior to the appearance of motor symptoms.
Like in IPD, disturbances such as hyposmia, depression, constipation and excessive daytime sleepiness may antedate the onset of classical motor symptoms in LRRK2-G2019S-PD.