SDHB and perivascular space measurement: Thus, the most common pathogenic germline variants in 57 young patients with PVs were the BRCA1 (39%, 22/57) gene, followed by the BRCA2 (28%, 16/57), TP53 (9%, 5/57), CHEK2 (7%, 4/57), PALB2 (5%, 3/57), and SDHB (4%, 2/57) genes.