The present disclosure is directed to methods of producing a modified nucleic acid comprising a precise deletion in a target nucleic acid in a cell comprising generating, within the cell, a first single strand break on a first strand of the target nucleic acid and a second single strand break on a second strand of the target nucleic acid, thereby forming a double strand break in the target nucleic acid having a first 3′ overhang and a second 3′ overhang; processing the first 3′ overhang and the second 3′ overhang with an exonuclease molecule, thereby deleting the segment of the target nucleic acid that was located between the first single strand break and the second single strand break, and forming a processed double strand break; and allowing the processed double strand break to be repaired by at least one DNA repair pathway, thereby producing the modified nucleic acid comprising the precise deletion in the target nucleic acid in the cell. Gene editing systems, vectors, polynucleotides, and methods of treatment are also disclosed herein.