While there was no statistically significant difference, there was a trend towards slower motor decline in α-syn SAA negative LRRK2 PD compared to those with α-syn SAA negative sporadic PD (difference = −0.63 (−1.96 to 0.70); p = 0.35) that seemed to be driven by R1441C/G + M1646T carriers (Tables 2 and 3). Here, LRRK2 is linked to Parkinson disease.