| Type | MGI:General | Description | consistent with X-inactivation, heterozygous females have a mosaic absence of dystrophin, but this diminishes with age such that at 10 days of age 37% of the fibers in a cross section of the quadriceps lack dystrophin staining, at 35 days of age only 18% of fibers lack dystrophin, and by 60 days of age only 4% lack dystrophin, in extraocular muscles the proportions of dystrophin expressing and non-expressing fibers is similar and in cardiac ventricular muscle approximately 30% of fibers lack dystrophin at 10 days of age, and 28% lack dystrophin at 60 days of age |
