To improve disease management of metachromatic leukodystrophy through an international disease registry and multistakeholder collaboration

The MLD initiative (MLDi) is a European disease registry for metachromatic leukodystrophy (MLD) and a multi-stakeholder collaboration. MLD is a rare inherited lysosomal storage disorder. The disease is caused by autosomal recessively inherited pathogenic variants in the ARSA or PSAP gene. A functional deficiency of the enzyme Arylsulfatase A leads to sulfatide accumulation throughout the body. Especially myelin sheaths (= white matter) in the central and peripheral nervous systems are severely affected. Patients suffer from progressive neurological deterioration and, if untreated, it leads to premature death.

The MLD initiative collects patient data for research and healthcare purposes. Researching rare diseases is difficult because of small patient numbers. Therefore, clustering data in a European database is needed. The MLDi initiates, coordinates, and manages various projects focused on improving the care for MLD.


● One independent disease registry for MLD in Europe

● To make this registry the product of a collaboration with expert centers in Europe. Thereby optimising the registry and maximising its impact

● To collect data for clinical research on MLD

● To collect data for research on the long-term outcomes of the novel therapies reaching the market. In order to answer both clinical and regulatory questions

● To initiate and coordinate research projects on MLD