As of date, CCM1 (KRIT1) on chromosome 7q, CCM2 (MGC4607/OSM/Malcavernin) on chromosome 7p, and CCM3 (PDCD10/TFAR15) on chromosome 3q are genes that are known to cause the familial form of CCM. The gene discussed is KRIT1; the disease is cerebral cavernous malformation.