The MLD initiative - Setting up and independent European Disease Registry for patients with Metachromatic Leukodystrophy

Metachromatic leukodystrophy (MLD) is a rare autosomal recessively inherited lysosomal storage disorder.


Due to a functional enzyme deficiency, the degradation of sulfatides and lysosulfatides is disrupted. Consequently, these sphingolipids will accumulate in the body, and cause, among others, severe neurological deterioration.

At present, there are few therapeutic options for pre- and early-symptomatic patients, for example allogeneic hematopoietic stem cell transplantation (HSCT), and new therapies including autologous HSC-based gene therapy and gene replacement therapy. Once the European Medicines Agency (EMA) authorizes these treatments, there will likely be further questions about their long-term effectiveness and potential adverse effects. To avoid fragmentation of data in different industry-led registries and to allow independent analyses of outcomes, the platform ‘Medicine for Society’ and the Amsterdam UMC have taken the initiative, with support of the European Leukodystrophy Association (ELA) and key opinion leaders in the field, to establish an independent European MLD patient registry. Independent disease registries led by medical doctors and researchers are important for fair and efficient healthcare & science. The data collected in the registry will provide comprehensive insights that will help improve the treatment and management of patients with MLD.


Primary objectives

  • Expand and professionalize our Amsterdam UMC MLD database into an independent European disease registry for MLD.

 Secondary objectives

  • Gain insights into the natural disease course, genotype-phenotype correlations, usefulness of biomarkers as well as effects of treatments.
  • To evaluate the long-term outcomes of the novel therapies reaching the market to answer both clinical and regulatory questions.


To determine a widely supported list of registry endpoints, an expert-based consensus procedure (modified Delphi study) will be performed. After the consensus on endpoints is achieved, the registry will be built in database software and will be taken in use. In multiple European MLD-expert centers both retrospective and prospective patient data will be collected.

Start date

Start date: 04-2020

Study type

Registry set-up, followed by a multicenter retrospective and prospective cohort study.


Daphne Schoenmakers