dbSNP (36), a repository for single-base nucleotide substitutions and short deletion and insertion polymorphisms, has nearly 18 million human records and 35 million more from a variety of other organisms. In addition to archiving the sequence that defines the variant, dbSNP maintains information about the validation status, population-specific allele frequencies, literature citations (PubMed) and individual genotypes for clustered reference records (rs numbers). These data are available on the dbSNP FTP site in XML-structured genotype reports that include information about cell lines, pedigree IDs and error flags for genotype inconsistencies and incompatibilities.
