Drug 'mends' muscular dystrophy

An experimental drug may be able to compensate for the genetic error responsible for some cases of Duchenne Muscular Dystrophy, US scientists hope. In rodents, the drug PTC124 was able to restore the muscle function normally lost in this disease, Nature reports. Trials have already begun in humans, although the results will take years. The drug works by allowing cells to read through certain mistakes in the genetic code for a protein - dystrophin - missing in 15% of patients with DMD.

Muscular dystrophy is a group of genetic disorders that cause the muscles in the body to gradually weaken over time and mobility to be lost. It shortens life span and there is currently no cure. DMD is the commonest and most severe form. Around 100 boys are born with the condition in the UK each year.

There are treatments that can help alleviate symptoms, such as muscle spasm, and enable people with MD to lead a good quality of life.

But scientists are striving to find a way of reversing or preventing the muscle damage.

PTC124 binds to a cell component called the ribosome, whose job it is to read genetic code and translate it so proteins can be made. In mice, the drug helped override the mutation in the dystrophin gene that tells it to halt production of the protein. Instead of stopping, the full-length dystrophin protein was made. It did not prevent the ribosome from reading correct "stop" signals in genetic codes for other proteins.

Lead researcher Dr H Lee Sweeney is on the scientific advisory board for PTC Therapeutics Inc, which is testing the drug. Dr Sweeney said: "This new class of treatment has the potential to help a large number of patients with different genetic diseases that have the same type of mutation."

Dr Marita Pohlschmidt, director of research at the Muscular Dystrophy Campaign, said the results were "very encouraging", particularly in the light of the ongoing human trials. She said: "This drug appears to have the potential to become a treatment in the longer term for some people with DMD. "We look forward to the publication of the full results of these clinical trials so that we can see more clearly what the prospects and possible timescales are for treatment."