A free, web-based application for rapid evaluation of the disease-causing potential of DNA sequence alterations. MutationTaster integrates information from different biomedical databases and uses established analysis tools (Supplementary Methods). Analyses comprise evolutionary conservation, splice-site changes, loss of protein features and changes that might affect the amount of mRNA. Test results are then evaluated by a naive Bayes classifier2, which predicts the disease potential. A typical query is completed in less than 0.3 seconds.