Reverse Transcriptase Inhibitors in AGS

Inclusion Criteria: * A molecular diagnosis of AGS i.e. biallelic or known dominant mutations, with pathogenicity assessed using our extensive mutation database / functional data, in any of TREX1, RNASEH2A, RNASEH2B, RNASEH2C and SAMHD1 genes * A pre-defined interferon signature (consistently present, moderate or high, on at least three occasions, over a period of 6 months prior to enrolment in the study) * Age ≥ 1 month and \< 18 years (either sex) * Patient beneficiary or affiliated to " health insurance" * Written informed consent Exclusion Criteria: * Pre-existing disease, not due to AGS, which would preclude the use of zidovudine, Lamivudine and abacavir (as currently assessed in routine clinical HIV-related practice) * HLA B57-01 positive result, which indicates a greater risk of abacavir hypersensitivity reaction * Patients with abnormally low neutrophile counts (\<0.75 x 109/l), or abnormally low haemoglobin levels (\<7.5 g/dl or 4.65 mmol/l)(zidovudine contraindication) * Positive serology for HIV, HBV * Known history of cirrhosis and history of clinically relevant hepatitis within last 6 months * Moderate to severe renal impairment * Pregnancy, breastfeeding * Patient participating to a biomedical research with drug