DMD and cardiac hypertrophy: Moreover, all electrocardiogram abnormalities and the end-diastolic volume in a 23-month-old mouse model of Duchenne Dilated Cardiomyopathy were normalized via the cardiac-specific expression of ∆H2-R15 mini-dystrophin, but this caused cardiac hypertrophy, and the size of this mini-dystrophin gene is nearly 7 kb, which is too large for packaging into the AAV capsids [23].