In the area of diagnosis and therapy of inborn metabolic diseases, the investigation of genetic and clinical data has special importance. These data are the basis of further research and are available in large amounts in the form of case reports within relevant scientific publications and several mutation or disease-oriented databases. However, a successful evaluation of these information is difficult because of the large heterogeneity regarding availability, representation and comparability. Our approach supports clinical researchers of inborn metabolic defects by collecting relevant information of mutations and its corresponding phenotypes in the Rare Metabolic Diseases Database RAMEDIS and their analysis by using a medical case-based reasoning component. Today, on the basis of already over 750 stored case reports, the retrieval of similar cases is possible. The output of the CBR tool is a weighted list of relevant patient cases with according diagnosis and therapy information.