MLD - Metachromatic Leukodystrophy


MLD is an inherited metabolic disorder.

Leukodystrophy is the collection of diseases that affect the growth and maintenance of the white substance  (myelin) in the brains. The main consequence of the disease is the degradation of white substance.



The transmission of the disease is autosomal recessive. This means that the 'weak' gene is passed on by both parents. The disease belongs to the group of lysosomal storage disorders.

A lysosome is a small part of a cell which ensures that substances are broken down and can be reused. Enzymes are required in this process. In the case of lysosomal storage diseases an enzyme in the lysosome operates insufficient or this enzyme is missing. Because of this, waste will accumulate and the cell does not function properly. This results in damage to tissues and organs. MLD occurs in the brains. Brain cells will die. The muscle control from the brains does not function well.


Age at which the disease begins

One can distinguish different forms, depending on the age at which the symptoms first occur:

  • Late infantile form: between first and second year of life,
  • Juvenile form: between the fifth and twelfth year of life,
  • Adult form: after the fourteenth year.



  • Spasticity,
  • Muscle weakness,
  • Impaired coordination of movements,
  • Slurred speech,
  • Frequently choking,
  • Problems with vision, leading to blindness or visual impairment,
  • Feeling in arms and legs upset,
  • Declined cognition and dementia,
  • Epilepsy,
  • Incontinence.


In the final stage the children or young adults can not perceive their environment and no longer respond to their environment. They are completely dependent on care.


Hopefully in the future it will be possible to stop the decline of white matter by means of stem cell transplants. Read more ...

Until that time treatment is tailored towards enabling the patient learn to deal with it as much as possible.


Life expectancy

MLD is a severe progressive disease with a low life expectancy. In children in whom the disease emerges at the lowest age, the disease process is fastest.