Gene therapy trial 'cures children'

[Jean M]

http://www.bbc.co.uk/news/health-23269778


A disease which robs children of the ability to walk and talk has been cured by pioneering gene therapy to correct errors in their DNA, say doctors. The study, in the journal Science, showed the three patients were now going to school. A second study published at the same time has shown a similar therapy reversing a severe genetic disease affecting the immune system....

Babies born with metachromatic leukodystrophy appear healthy, but their development starts to reverse between the ages of one and two as part of their brain is destroyed.

Wiskott-Aldrich syndrome leads to a defective immune system. It makes patients more susceptible to infections, cancers and the immune system can also attack other parts of the body.

The technique, developed by a team of researchers at the San Raffaele Scientific Institute in Milan, Italy, used a genetically modified virus to correct the damaging mutations in a patient's genes.

[Jean M]

Here is the paper: Alessandra Biffi, Lentiviral Hematopoietic Stem Cell Gene Therapy Benefits Metachromatic Leukodystrophy, Science , Published Online July 11 2013

http://www.sciencemag.org/content/early/2013/07/10/science.1233158.abstract


Metachromatic leukodystrophy (MLD) is an inherited lysosomal storage disease caused by arylsulfatase A (ARSA) deficiency. Patients with MLD exhibit progressive motor and cognitive impairment and die within few years of symptom onset. We used a lentiviral vector to transfer a functional ARSA gene into hematopoietic stem cells (HSCs) from three presymptomatic patients who showed genetic, biochemical, and neurophysiological evidence of late infantile MLD. After reinfusion of the gene-corrected HSCs, the patients showed extensive and stable ARSA gene replacement, which led to high enzyme expression throughout hematopoietic lineages and in cerebrospinal fluid. Analyses of vector integrations revealed no evidence of aberrant clonal behavior. Notably, the disease did not manifest or progress in the three patients 7 to 21 months beyond the predicted age of symptom onset. These findings indicate that extensive genetic engineering of human hematopoiesis can be achieved with lentiviral vectors and that this approach may offer therapeutic benefit for MLD patients.