Similarly, relative improvement of UPDRS II-IV and LEDD reduction were not significantly different after 6–12 months in a French study comparing nine LRRK2-PD patients, mainly G2019S carriers, to 60 idiopathic PD patients using a t-test.29 The UK screening study mentioned above also reported that differences in outcome were statistically non-significant, yet this study included only five LRRK2 patients.20 This evidence concerns the gene LRRK2 and Parkinson disease.