Abstract 159: Exceptional Aggressiveness of CCM3 Phenotype

Introduction: Familial forms of cerebral cavernous malformations (CCM) account for about 1/3 of cases, involving autosomal dominant inheritance at 1 of 3 gene loci. Few studies have examined any special features of the rarest cases with CCM3 (PDCD10) mutation at q3, constituting <15 % of probands genotyped by sequential mutation screening, and <2% of CCM cases at large. Hypothesis: We hypothesize that CCM3 cases have unique phenotypic features not recognized in the more common CCM1 and 2 families, or in sporadic cases. Methods: Twelve probands including 17 subjects with confirmed CCM3 mutations were prospectively enrolled through systematic facilitated referral by the patient advocacy group Angioma Alliance. Clinical features were catalogued, including high sensitivity susceptibility weighted imaging (SWI). Rates of overt hemorrhage were determined based on adjudicated criteria. Comparisons were made to systematic literature review of natural history data on non-CCM3 cases. Results: The first overt hemorr...