Molecular genetic investigations in the CCM1 gene in sporadic cerebral cavernomas

Objective: Cerebral cavernous malformations (CCM) occur in familial and sporadic forms that cannot be distinguished by phenotype. Mutations in Krit1, a gene located at the CCM1 locus on chromosome 7q21, account for the majority of familial CCM-cases. The authors investigated the role that mutations at the CCM1 locus play in sporadic cavernomas and the prevalence of occult familial forms among symptomatic cavernomas. Methods: The authors screened the DNA of cavemomas and adjacent normal brain tissue of 72 consecutive patients treated at the Neurosurgical Department/Ludwig-Maximilian University for mutations in Krit1. Eight of the patients had been suspected to have a mutation at CCM1, as they showed multiple cavernomas or clinically familial forms. Results: None of the patients showed a mutation at the CCM1 site, either in cavernomas or in normal brain tissue. Conclusion: Mutations in Krit1 are seldom a cause of sporadic cavernomas.