ATM and perivascular space measurement: Modest associations were observed between PVs and young age at diagnosis for ATM (OR 1.22, 95% CI 1.08–1.37) and CHEK2 (OR 1.34, 95% CI 1.21–1.47) genes, but not for PALB2 (OR 1.12, 95% CI 0.98–1.27).