A 71-year-old female patient with hepatitis C virus genotype 1 had previously discontinued interferon (IFN)-α plus ribavirin therapy, pegylated IFN-α (pegIFN-α) monotherapy, and natural IFN-α monotherapy because of arrhythmia, interstitial pneumonia, and severe neurovegetative symptoms. This evidence concerns the gene IFNA1 and Arrhythmia.