Gene Therapy for Rare Central Nervous System Diseases Comes to Age

Gene therapy for rare inherited neurologic diseases has entered the clinics. One strategy relies upon the replacement of brain microglia using hematopoietic stem cell gene therapy with lentiviral vectors. Therapeutic success using this approach has been obtained in X-linked adrenoleukodystrophy and metachromatic leukodystrophy. The other strategy relies upon the intracerebral administration of adeno-associated virus vectors encoding lysosomal enzymes. Therapeutic trials are ongoing in Batten's disease, metachromatic leukodystrophy, and Sanfilippo type A and B diseases.