The caudate ASI for the PD cases with GBA mutations (Mann-Whitney U-test, median ASI 0.42 [0.33–0.56], p<0.001) was different to the control value of 0.92 (interquartile range 0.89–0.92) (Table 1 and Figure 1a). The gene discussed is GBA1; the disease is Parkinson disease.