CCM2 and cerebral cavernous malformation: We screened CCM-related genes through whole-exome sequencing (WES) and identified a novel missense variant (c.331G > C) in CCM2 that caused at least seven cases of CCMs; we also identified the exon 13 deletion in KRIT1 coexisting with the CCM2 mutation in patient IV-2 and her father (patient III-1H).