Genetic screening for LRRK2 gene G2019S mutation in Parkinson's disease patients from Southern Italy.

Leuchine-rich repeat kinase 2 (LRRK2) gene mutations are a common cause of familial and sporadic Parkinson disease (PD). G2019S is the most frequent mutation of the LRRK2 gene and has been reported in about 5-6% of familial and 1-2% of sporadic PD cases. The aim of this study is to investigate the G2019S frequency in a series of 58 familial and 70 sporadic PD patients recruited from Campania, a region in Southern Italy. We identified one heterozygous G2019S mutation in a PD patient who also suffered from obsessive disorder and depression and presented hallucinations and delusional jealousy while he was treated with l-dopa, pramipexole, and amantadine. Brain (18)F-deoxy-glucose PET showed relative decrease of glucose metabolism in the caudate nuclei and to a lesser extent in cortical parietal/frontal regions. The patient's mother also had PD and molecular analysis demonstrated that she carried the same mutation. G2019S mutation frequency is rather low in overall patients (0.8%) and in the familial group (1.7%), suggesting that it may be an uncommon cause of PD in Southern Italy.