A genotype is a way to put the hepatitis C virus (HCV) into categories based on similar genes. It’s important to know and understand HCV genotypes because different genotypes respond differently to medicines that treat and cure HCV.
HCV has six genotypes, labeled 1 through 6. There are also subtypes labeled with letters, for example, genotypes 1a and 1b. Most people are infected by a single, dominant genotype, but it is possible to have more than one at the same time (called a mixed infection).