While high quality information regarding variation in genes is currently available in locus-specific or specialized mutation databases, the need remains for a general catalog of genome variation to address the large-scale sampling designs required by association studies, gene mapping, and evolutionary biology. In response to this need, the National Center for Biotechnology Information (NCBI) has established the dbSNP database http://ncbi. nlm.nih.gov/SNP/ to serve as a generalized, central variation database. Submissions to dbSNP will be integrated with other sources of information at NCBI such as GenBank, PubMed, LocusLink, and the Human Genome Project data, and the complete contents of dbSNP are available to the public via anonymous FTP. Hum Mutat 15:68-75, 2000. Published 2000 Wiley-Liss, Inc.