However, the familial or hereditary form (FCCM), caused by autosomal‐dominant loss‐of‐function (LOF) mutations in KRIT1/CCM1 (53%–65% in FCCM), CCM2/MGC4607 (10%–16%), or PDCD10/CCM3 (5%–15%) (Labauge et al. 2007; Flemming et al. 2023), constitutes a rare genetic disorder with an estimated prevalence of 1–5:10000 (Orphanet–OMIM 11860/603284/603285/619538) (Labauge et al. 2007). Here, CCM2 is linked to hereditary disease.