Cerebral cavernous malformation

Mutations in at least three genes, KRIT1 (also known as CCM1), CCM2, and PDCD10 (also known as CCM3) are known to cause familial CCM. Mutations in these three genes account for 85 to 95 percent of all cases of familial CCM. The remaining 5 to 15 percent of cases may be due to mutations in unidentified genes or to other unknown causes. Mutations in the KRIT1, CCM2, and PDCD10 genes are not involved in sporadic CCMs. The cause of this form of the condition is unknown.^[1]

While we have not identified any reports of patients with mutations in more than one of the above-mentioned genes, it is not outside the realm of possibility. Nonetheless, it is highly unlikely. Molecular genetic testing can identify if you have one or more of the genes associated with this disorder.

Yes, genetic testing is available for familial cerebral cavernous malformation.  Genetic testing can detect a mutation in one of the three known CCM genes (KRIT1, CCM2 or PDCD10) in 70 percent to 80 percent of individuals from families with CCM. The remaining 20 percent to 30 percent of cases may be due to unidentified genes or to other unknown causes.^[1] If no mutation is detected in one of those three genes, research testing may be performed to identify families that demonstrate linkage to a fourth potential location of a CCM gene.^[2]

You can find a list of laboratories that provide genetic testing for CCM through the Genetic Testing Registry (GTR). The GTR is a centralized online resource for information about genetic tests. The intended audience is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Genetic testing can not be performed on a blood sample from someone with sporadic CCM becuase the gene mutation may be located in tissues other than the blood.^[3]

Cerebral cavernous malformations (CCMs) affect about 0.5 percent of the population worldwide.^[1] Eighty percent of these cases are sporadic and 20 percent are familial.^[4]