A genotype is a combination of genes within the virus. It is a family; it™s related to others but maintains its identity.

There are 6 different genotypes (1a, 1b, 2a, 2b, 2c, 3a, 3b, 4a, 5a, 6a) with 1a being the most common in North America and 1b the second most common.

Each genotype has a different impact on the progression of liver disease and the effectiveness of treatment.