Abstract: The present disclosure provides genome editing systems, compositions and methods. The genome editing system comprises at least one nuclease that generates blunt-ended DNA breaks in a sequence-specific manner, wherein the genome editing system is configured to form a first and a second blunt-ended double strand break in an intron of a gene, wherein the intron comprises a splice donor site mutation that alters splice site recognition, thereby excising a segment of the intron and simultaneously joining DNA ends flanking the excised segment of the intron to constitute a functional donor splice site.

Abstract: Described are compounds and methods useful in the promotion of muscle growth, the treatment of muscle loss or insufficient muscle growth, and the treatment of fibrotic conditions.