MC1R and Parkinson disease: When we examined the relationship between genetic status and rate of change in non-motor decline, we found that participants with MC1R PD (0.52; β diff=0.10 (−0.01 to 0.20) p=0.070) exhibited a nominally higher rate of change in MDS-UPDRS I than participants with sporadic PD (0.42 (0.34 to 0.50)).