Enrolment of FDRs of the proband
| Item | Value |
| Probands with ≥1 enrolled FDRs, No. (%) | 43 (84.31) |
| Probands with 100% enrolled FDRs, No. (%) | 13 (30.23) |
| Probands with FCCM, No. (%) | 33 (76.74) |
| No. of living FDRs per proband (M (P25–P75) | 5 (3–7) |
| No. of living FDRs enrolled per proband (M (P25–P75) | 3 (2–3) |
| % Living FDRs enrolled per proband (M (P25–P75) | 50.0% (28.6%–100%) |
| Number of people who self-reported, No. (%) | 5 (4.35) |
| Relatives with CCMs diagnosis prior to enrolment, No. (%) | 4 (11.43) |
FCCMs, familial cerebral cavernous vascular malformations; FDRs, first-degree relatives.