In 2017, WHO recommended a comprehensive package of care for people living with AHD, including a CD4 count to diagnose AHD, rapid ART initiation with adherence support, and tuberculosis diagnostics (eg, sputum Xpert and urine lipoarabinomannan), tuberculosis preventive therapy, serum cryptococcal antigen screening with pre-emptive fluconazole treatment if cryptococcal antigen-positive, and co-trimoxazole to prevent bacterial infections. The gene discussed is CD4; the disease is mitochondrial DNA depletion syndrome 4a.