This is a randomized, multi-site, placebo-controlled trial of a fixed dose combination (FDC) of grazoprevir (MK-5172) 100 mg + elbasvir (MK-8742) 50 mg in participants with chronic Hepatitis C Virus (HCV) genotype (GT) 1, GT4 or GT6 with inherited blood disorders. The primary hypothesis is that the proportion of participants treated with grazoprevir+elbasvir achieving Sustained Virologic Response (SVR) 12 weeks after the end of all study therapy (SVR12) will be greater than the reference rate of 40%.