We tested in a population of patients with iRBD, a risk group for future PD, if deficits of rhythm perception or production can act as an early marker of PD and whether individual differences in these abilities are related to other well‐known early markers of PD, such as motor and non‐motor aspects of daily living, dysautonomia, olfaction dysfunction, and DAT abnormalities. This evidence concerns the gene SLC6A3 and Parkinson disease.