Tens of thousands of Americans suffer from muscular dystrophy (MD), a disease that gradually deteriorates a person's skeletal muscle. While there is no effective cure, scientists know MD is caused by a genetic defect and are searching for treatments that will stop or retard the deterioration of muscle. In June, American and British researchers announced the success of a long-term treatment that repairs the genetic defect in Duchenne muscular dystrophy, the most common childhood form of MD.

Last fall, these researchers injected a short strand of nucleic acid into the shin muscle of a six-week old golden retriever - which had a genetic defect that leads to Duchenne MD in dogs - in order to maintain normal levels of dystrophin, the muscle protein missing in Duchenne MD. Their goal was for the nucleic acid to trigger the dog's system to correct the genetic defect. Eleven months later, the injected muscle continues to show normal levels of dystrophin.