Dystrophin (DMD) gene target sequence (DMD)

The target is a specific double-stranded DNA sequence within the human Dystrophin (DMD) gene, located on the X chromosome (HGNC:2928). This gene encodes the dystrophin protein, which is essential for maintaining the structural integrity of muscle cell membranes by linking the internal cytoskeleton to the extracellular matrix (UniProt: P11532). Mutations in the DMD gene, such as frame-shift deletions, lead to Duchenne Muscular Dystrophy (DMD), a progressive and fatal muscle-wasting disease (NIH: Genetic and Rare Diseases Information Center). This DNA sequence is specifically defined by its complementarity to a Cas12a (formerly Cpf1) CRISPR RNA (crRNA) and its proximity to a TTTV protospacer adjacent motif (PAM) (Zetsche et al., 2015). The interaction with the Cas12a endonuclease facilitates site-specific double-strand breaks, which can be exploited for therapeutic gene editing, such as exon skipping or frame restoration, to treat muscular dystrophy (Amoasii et al., 2018). By targeting this sequence, researchers aim to restore the production of a functional dystrophin protein in muscle tissues. This genomic target is a focal point for next-generation gene therapies designed to provide a permanent cure for DMD patients.

Other names

DMD geneDystrophin locusCas12a DMD target siteDMD genomic DNADMD exon target

The target DNA sequence is recognized by a Cas12a-crRNA complex through base-pairing and recognition of a T-rich protospacer adjacent motif (TTTV), leading to a site-specific staggered double-strand break. This break is subsequently repaired by cellular mechanisms like non-homologous end joining (NHEJ) or homology-directed repair (HDR) to delete deleterious mutations, disrupt splice sites, or restore the dystrophin reading frame (Zetsche et al., 2015; Amoasii et al., 2018).