Genetic heterogeneity and absence of founder effect in a series of 36 French cerebral cavernous angiomas families

Cerebral cavernous angiomas malformations (CCM) can be inherited as an autosomal dominant condition. CCM1, a yet unidentified gene mapping on 7q21-q22, was shown to be involved in all CCM Hispano-American families, with a strong founder effect. Genetic heterogeneity in non Hispano-American families was established in two families. We conducted a genetic linkage analysis an 36 French CCM families using eight microsatellite markers mapping within the CCM1 interval, Admixture analysis showed that 65% of these families were linked to the CCM1 locus, Haplotypes analysis of CCM1-linked families did not show any evidence for a strong founder effect.