At the University of Oslo, he established and directed through the years 1954-1964 the Institute of Medical Genetics, along somewhat similar lines as the Copenhagen Institute. In 1964 he succeeded Tage Kemp in the Chair as Professor of Medical Genetics, Copenhagen University. Together with Hans Eiberg he established Copenhagen Family Bank in 1972, a store of DNA samples, comprising about 1000 large Danish families as a basis for a Resource Center for Linkage analysis, RC-LINK, to study also familial diseases such as cystic fibrosis and Batten disease, both of which are among diseases mapped at the center.