DBASS5 is a publicly accessible resource containing details of aberrant 5' splice sites generated as a result in disease-causing mutations in human genes.

Nucleotide sequences of authentic and aberrant splice donor sites can be retrieved by phenotype, gene, mutation, by the location of cryptic/de novo donor sites, and by their distance from authentic sites. DBASS5 also provides a basic summary of cryptic and de novo 5' splice sites and their distribution across exons and introns. In addition, it compares the strength of authentic and corresponding aberrant sites using several splice site prediction tools. The database also contains alternative 5' splice sites that have been associated with aberrant expression of pre-existing mRNA isoforms and unambiguous phenotypic consequences due to genetic variants in the vicinity of splice donor sites. The database currently contains 431 records (214 in exons and 217 in introns).

DBASS5 is regularly updated and is intended as a reference tool for clinical geneticists, biochemists, cell biologists and all investigators studying consequences of genetic changes at the level of pre-mRNA splicing as well as mechanisms underlying 5' splice site selection.