In summary, the Gaussian distribution of low dystrophin levels obtained in the mdx-XistΔhs mouse and the ease of generating large numbers of mice, make it a good mouse model for more detailed research on the effect of low levels of dystrophin on several aspects of DMD pathology and effects of future treatment strategies for dystrophinopathies. The gene discussed is DMD; the disease is neuromuscular disease caused by qualitative or quantitative defects of dystrophin.