Using the Cost-Effectiveness of Preventing AIDS Complications-International model, we simulated a cohort of non-hospitalised people living with HIV (aged >19 years) initiating antiretroviral therapy (ART), 25% of whom had AHD (CD4 count <200 cells per μL and/or WHO stage 3 or 4 disease). The gene discussed is CD4; the disease is mitochondrial DNA depletion syndrome 4a.