Respondents aged 50–64 years (70, 37%) and those over 64 years (62, 38.8%) were more likely to have other reasons (such as believing they were at risk of PCa or having prostate symptoms) for having the PSA test, in comparison with men aged 40–49 years (8, 14.5%), p<0.001. This evidence concerns the gene KLK3 and posterior cortical atrophy.