Immunohistochemical studies show truncated dystrophins in the myotubes of three fetuses at risk for Duchenne muscular dystrophy.

We have performed immunohistochemical studies on muscle tissue of three 12 week old fetuses at risk for DMD, using antisera directed against regions located NH2-proximally and centrally in the rod shaped spectrin-like domain and against the COOH-terminus of dystrophin. All three fetuses had a family history of DMD. Truncated dystrophins were identified in all three cases by a positive reaction with the NH2-proximal antibody, different reactions with the central antibody, and a negative reaction with the COOH-terminal antibody. These data indicate that a panel of antibodies would, in principle, permit 'immunological' mapping of dystrophin mutations. This is diagnostically important in the 35% of families where no mutation is detectable at the DNA level. Secondly, by using this mapping technique it may also become possible to identify the at risk haplotype when DNA analysis is not informative. This may be of great value in DMD carrier detection.