The large-scale diagnosis of genetic causes of rare diseases enabled CENTOGENE to build the largest real world biodatabank of rare diseases encompassing more than 700 000 samples. The combination of phenomics-, genetic- multiomic data and whole blood samples on filter cards make this biodatabank a unique tool to understand rare diseases. While many rare diseases are seen as monogenetic disease, a deep understanding of the disease is essential to fully understand differences in the disease etiology. The type of disease-causing mutation, the tissues being affected and disease modifying factors have strong impact on drug discovery efforts and clinical development programmes. In the presentation examples of rare diseases will be discussed in which understanding of the clinical subtype of the disease is directing the strategy of drug discovery efforts.