The other materials which are use by the two strategies are the ICD-10 [14], and UMLS [101. U MLS metathesaurus will used by the first strategy. Since the UMLS methathesaurus contains a huge number of terms and their variants, a CUI (Concept Unique identifier) is used to differentiate between oncepts. The first strategy refers to the and Orphanet-ICD-10 link-based mapping It involves two modes of matching: manual matching (Orphanet/ICD-10) and the automatic matching (between Orphanet and MesH). The matching between Orphanet and MESH relies on external source which is the UMLS Metathesaurus that contains the MeSH terms. For example, the orphanet term which is called" Cushing Syndrome" is manually matched to ICD-10 term called "Cushing syndrome E24". The UMLs takes the result o the manual matched ICD term "Cushing syndrome E24"and checks for its concept unique identifier. Moreover, it checks the MESH term "Cushing Syndrome". The two terms can be matched if they have the same concept unique identifier Second strategy is String Based Matching that its objective is match between the orphanet and MESH terms and its ariants without the use of External source such as the UMLS Two terms are matched if they are equa The strategy involves also the use of two natural language processing methods such as the stop word elimination and stemming to enhance the matching process