A dystrophin missense mutation showing persistence of dystrophin and dystrophin-associated proteins yet a severe phenotype

A muscle biopsy from an X-linked muscular dystrophy pedigree showed normal dystrophin and dystrophin-associated proteins. Linkage to multiple markers within the dystrophin gene (LOD = 2.7, Theta = 0) indicated a primary dystr ophinopathy. Sequencing of the entire dystrophin RNA revealed a single miss ense mutation (D3335H) in the unique carboxyl-terminal domain. This is the first report showing that a relatively severe dystrophinopathy can occur de spite the correct localization of dystrophin and dystrophin-associated prot eins.