A method for detecting a mutation related to the gene encoding OAS1. This and other disclosed mutations correlate with resistance of humans to viral infection including hepatitis C. Also provided is a therapeutic agent consisting of a protein or polypeptide encoded by the mutated gene, or a polynucleotide encoding the protein or polypeptide. Inhibitors of human OAS1, including antisense oligonucleotides, methods, and compositions specific for human OAS1, are also provided.
