What this covers
Metachromatic leukodystrophy (MLD) is a lysosomal storage disease in which the protective myelin covering of nerve fibres breaks down, causing a progressive loss of movement and thinking skills. It arises from a shortage of the enzyme arylsulfatase A (ARSA) or a protein that activates it, due to faults in the ARSA or PSAP genes. This review brings together the diagnostic methods, animal models and treatment strategies being explored for the condition.
Key takeaways
- The severity of MLD is shaped by how much arylsulfatase A activity remains, which depends on the particular gene fault involved.
- There is currently no effective cure, and reported cases of bone marrow or cord blood transplantation have not been enough to halt the neurological decline.
- Gene therapy — including approaches that deliver a healthy copy of the ARSA gene using adeno-associated viruses, as well as stem cell and combined gene–cell therapies — has produced encouraging results.
Why it matters
With no established cure, understanding which treatments show promise and how to diagnose the disease well is essential for improving care and guiding the next generation of therapies.
