Treatment of leukodystrophies: Advances and challenges.

Leukodystrophies, a group of genetic disorders primarily affecting brain white matter, were once considered untreatable. Advances in MRI and genetic diagnostics now allow most patients to receive a genetic diagnosis, and emerging treatments are shifting the field from therapeutic nihilism to cautious optimism. Allogenic haematopoietic stem cell transplantation (HSCT), used since the 1980s, has shown efficacy in specific leukodystrophies, such as adrenoleukodystrophy and metachromatic leukodystrophy, when administered early. Gene therapy has become a viable option, with ex vivo approaches like atidarsagene autotemcel providing promising outcomes for early-onset MLD. Trials for gene replacement and antisense oligonucleotide therapies are ongoing for several leukodystrophies, including Canavan disease and Alexander disease. Certain treatments, such as guanabenz for Vanishing White Matter, target disease-specific dysregulated molecular pathways. Despite these advances, challenges remain, including the ultrarare nature of most leukodystrophies, limited natural history data, high treatment costs, and barriers to accessibility. Future developments, including newborn screening and close international collaboration, aim to enhance early diagnosis, refine treatment timing, and expand access to innovative therapies.