OMIM
Online Mendelian Inheritance in ManĀ® (OMIM) is a comprehensive, authoritative, and free compendium of human genes and genetic phenotypes. The full-text, referenced overviews in OMIM contain information on all known mendelian disorders and over 15,000 genes. OMIM focuses on the relationship between phenotype and genotype. It is updated daily, and the entries contain copious links to other genetics resources.