Fig. 1: Number of potential individuals with both ICA and PD as a function of age in the US.

a Demographic of age distribution in the US (year 2000). b Probability of Parkinson’s disease (PD) in North America as a function of age. c Estimated number of potential individuals with both isolated congenital anosmia (ICA) and PD in the US general population according to age (2018).