A method of treating, preventing, and/or curing a disease or disorder characterized by unbalanced nucleotide pools in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a composition comprising a transgene encoding thymidine kinase 2 (TK2), deoxyguanosine kinase (dGK), thymidine phosphorylase (TP), p53 inducible small subunit of ribonucleotide reductase (p53R2), succinyl-CoA ligase ADP-forming subunit beta (SUCLA2), succinyl-CoA ligase GDP-forming subunit alpha (SUCLG1), mitochondrial inner membrane protein MPV17 (MPV17), and/or DNA polymerase subunit gamma (POLG).