To link clinical vocabulary of diseases to gene entries in Online Mendelian Inheritance in Man (OMIM), we comprehensively matched diseases from Unified Medical Language System (UMLS) Metathesaurus to the OMIM text in Allelic Variant fields that describe relations between the mutations or polymorphisms of the genes and the phenotypes. Out of 1,786 genes having the field, 1,445 genes (80.9%) had matches with 2,417 types of diseases or disorders. The links are accessible at http://www.genelexpo.jp/diseases/.