A mutation in the Phospholamban gene where the Arginine at position 14 (PLN-R14Del) is missing is causing a severe cardiomyopathy often leading to cardiac transplantation in the Netherlands. We estimated that approximately 25% of all transplanted patients carry this mutation. The origin is dated somewhere around the year 1300 in the north of country. Currently we have identified 1600 carriers with the identical mutation. We are in the process of developing and applying gene therapy to come to a specific treatment for the 700 carriers with symptoms we see today.