DBA2.B6-DMD*Q995X mice carry a c.2983C>T (p.Q995*) mutation in the Dmd gene, which introduces a premature termination codon (PTC) triggering nonsense-mediated mRNA decay (NMD) in eukaryotes. NMD degrades PTC-containing aberrant mRNAs to minimize gene expression errors, as these mRNAs may translate into harmful gain-of-function or dominant-negative proteins disrupting physiological mechanisms. The mutation combined with the murine NMD mechanism leads to the degradation of most Dmd transcripts in DBA2.B6-DMDQ995X mice, with remaining transcripts encoding nonfunctional truncated dystrophin, resulting in loss of dystrophin function. Additionally, the inherent muscle regeneration dysfunction in the DBA/2 strain exacerbates myopathic phenotypes, including significant muscle atrophy, fibrosis, and pronounced muscle weakness, more accurately mimicking human DMD progression and severity. This makes DBA2.B6-DMD*Q995X mice, with their lack of functional dystrophin, ideal for modeling Duchenne muscular dystrophy (DMD) and evaluating therapeutic strategies.