Cavernous malformations (angiomas) affecting the central nervous system and retina can be inherited in autosomal dominant pattern (OMIM 116860). These vascular lesions may remain clinically silent or lead to a number of neurological symptoms including seizure, intracranial hemorrhage, focal neurological deficit, and migraine. We have mapped a gene for this disorder in two families, one of Italian-American origin and one of Mexican-American origin, to markers on proximal 7q, with a combined maximum lod score of 3.92 (theta of zero) with marker D7S479. Haplotype analysis of these families places the locus between markers D7S502 proximally and D7S515 distally, an interval of approximately 41 cM. The location distinguishes this disorder from an autosomal dominant vascular malformation syndrome where lesions are primarily cutaneous and that maps to 9p21.