Linkage analyses predicts that 40 % of patients with familial forms is linked to CCM1 locus, 40 % to CCM3 and, only 20 % to CCM2 [10–13]; however, according with reported experimental data, these frequencies are not confirmed by an our recent screening of a cohort of Italian patients with CCMs [9]. This evidence concerns the gene CCM2 and cerebrocostomandibular syndrome.