"Estimates of the prevalence of the Vascular Type of EDS vary from 1: 50,000 to 1: 100,000. Because many families with the vascular type of EDS are identified only after a severe complication or death, it is likely that individuals/families with COL3A1 mutations with mild phenotype do not come to medical attention and therefore goundetected." (Byers et.al 1995)