Gene therapy promises to wipe out rare childhood diseases
A new type of gene therapy has shown promise in wiping out two rare childhood diseases, apparently without the risks of causing cancer, international researchers said Thursday.
The method used an HIV virus vector and the patients’ own blood stem cells to deliver a corrected version of a faulty gene, said the report in the US journal Science.
As a result, six children are doing well, 18 to 32 months after their operations, said lead scientist Luigi Naldini of the San Raffaele Telethon Institute for Gene Therapy in Milan.
“Three years after the start of the clinical trial, the results obtained from the first six patients are very encouraging. The therapy is not only safe, but also effective and able to change the clinical history of these severe diseases.”
Three of the children suffer from metachromatic leukodystrophy, a disease of the nervous system which is caused by mutations in the ARSA gene.
Babies with the disease appear healthy when they are born, but as they grow, they start to lose cognitive and motor skills. There is no cure.
The new gene therapy approach has halted progression of the disease in these three children, researchers said.
The other three children in the study have Wiskott-Aldrich syndrome, which is caused by mutations in the WAS gene and results in recurring infections, autoimmune diseases, frequent bleeding, and a high risk of cancer.
The treatment has caused the children’s symptoms to lessen or vanish altogether, the researchers said.
Previous attempts at gene therapy for a range of diseases, including Wiskott-Aldrich Syndrome, have shown some success, but over the long term it was discovered that immune-compromised patients sometimes developed blood cancer.
Researchers now believe that the viral vectors used in the past may have somehow activated a part of the DNA that caused cancer.
Scientists have been greatly cautious with human trials on gene therapy since the 1999 death of an American teenager, Jesse Gelsinger, whose participation in a trial for a rare metabolic disorder overwhelmed his immune system and led to death by multiple organ failure.
More at: http://www.rawstory.com/rs/2013/07/11/gene-therapy-promises-to-wipe-out-rare-childhood-diseases/