This booklet summarizes our current knowledge of founder mutation populations (‘extended families’) in the Netherlands, among other aspects providing insight in where these patients can be expected (coloured maps of the prevalence in the 99 Dutch postal code regions are provided for every phenotype) and what their precise phenotype is.Combines articles from different disciplines, using basic and clinical information, which lead to important advances in our knowledge of hereditary cardiovascular disease Summarizes our current knowledge of founder mutations populations in the Netherlands Provides full colored maps of the prevalence of founder mutations for every phenotype