An international team of researchers reports that gene therapy that addresses the genetic defect that underlies the brain demyelination disorder X-linked adrenoleukodystrophy (ALD) succeeded in halting progression of the disease in 2 young boys (Cartier N et al. Science. 2009;326818-823).
ADL, which is caused by mutations in the gene that encodes the ALD protein, can be treated with hematopoietic stem cell transplantation, but the disorder is fatal when a suitable matched donor is not available. The new approach involves removing blood stem cells from the patient and using a lentiviral vector derived from a disabled version of HIV to introduce a working copy of the ALD gene into these cells. The patient then receives an infusion of the modified cells after undergoing myeloablative treatment to destroy the bone marrow.
Stephenson J. Gene Therapy and ALD. JAMA. 2009;302(23):2531. doi:10.1001/jama.2009.1841