Many steps go into developing a clinical viral gene therapy. The course starts with appropriate disease selection and moves through the many hurdles of in-vitro testing, animal model validation and proof-of-concept studies, all the way through pre-clinical large animal studies. In this thesis, I propose to outline the process of developing a translation pathway for a gene therapy using recombinant adeno-associated virus (rAAV). I will expand on this outline using data that I have generated during the course of my Ph.D. that ranges from animal model validation all the way through pre-clinical vector stability studies. Two disease models will be discussed throughout this thesis, Cockayne Syndrome (CS) and Alpha-1 Antitrypsin Deficiency (AATD). Cockayne Syndrome is a rare autosomal recessive genetic disorder involving mutations in either the CSA or CSB gene, leading to defects in DNA repair. Clinically this presents as progressive degeneration of the central nervous system, retina, cardiovascular system, and cochlea, which leads to mental retardation, post-natal growth defects, ocular abnormalities, and shortened life expectancy. Alpha-1 antitrypsin is a serine protease inhibitor largely produced in the liver that mainly functions to inhibit neutrophil elastase within the lung. AATD leads to an increased risk of emphysema, with shortened life expectancy, and also results in accumulations of mutant AAT polymers in the liver, sometimes leading to liver failure. Using these two disease models I will outline the upstream and downstream pre-clinical work as well as the transition to clinical trials of a rAAV based gene therapy.