AGS is known to be caused by misspellings of some of the genes in your cells. It is believed that these spelling errors began in your mom or dad’s cells and were inherited when you were born. We believe that the genetic misspellings cause DNA (the building blocks of genes) to be mismanaged in AGS, leading to a build-up of DNA within cells. The body reacts to these cells as if they are infected by a virus, attacking them with your immune system. We believe that this response is what causes the symptoms of AGS and that treatment with drugs that fight viruses might reduce your symptoms.This study will use medications commonly used to fight an HIV infection called Tenofovir (TDF)/ Emtricitabine (FTC). Even though you don’t have HIV, the medicine works in a way that we believe will help your disease. Mice with misspellings in the AGS genes have also been shown to build-up DNA in their cells and got better when treated with special medications used in patients who have an HIV infection. The study will last for 13 months and will require that you come to CHOP on a regular basis to receive either the study drugs (TDF/FTC) or placebo. We will also collect blood, urine, and cerebrospinal fluid from you. You will also be asked to complete MRIs, physical exams, interviews, and questionnaires.