Rare diseases are frequent in pediatrics. In university children‘s hospitals almost 60% of children treated as inpatients suffer from rare diseases. As rare diseases in pediatrics are often severe, complex and chronic, affected families have a high disease burden. The burden is particularly severe in cases with an unclear or unknown diagnosis because the uncertainty of the child’s prognosis adds to the burden of the current suffering and in some cases the molecular diagnosis will enable a new targeted treatment option. The innovation fund project TRANSLATE-NAMSE, financed by the Federal Joint Committee (GBA), has previously evaluated the possibility of improved diagnostics for children and adolescents with undiagnosed rare diseases. Based on interdisciplinary case conferences and supported by the implementation of exome sequencing, 30% of previously uncertain diagnoses could be definitively clarified.