Although his brain MRI showed no apparent atrophy or signal abnormalities (Fig. 3A), dopamine transporter SPECT (DAT-SPECT) revealed decreased uptake in the bilateral putamen (specific binding ratios [SBRs]: right, 3.57; left, 2.23 [prediction intervals 95% lower limit to the mean SBR in the 70–79 age group, 4.42]; asymmetry index, 46.3%; Fig. 3B). This evidence concerns the gene SLC6A3 and Atrophy.