Metachromatic leukodystrophy is an inherited disorder characterized by the accumulation of fats called sulfatides in cells. This accumulation especially affects cells in the nervous system that produce myelin, the substance that insulates and protects nerves. Nerve cells covered by myelin make up a tissue called white matter.
Causes: Metachromatic leukodystrophy (MLD) is usually caused by the lack of an important enzyme called arylsulfatase A. Because this enzyme is missing, chemicals called sulfatides build up in and damage the nervous system, kidneys, gallbladder, and other organs. In particular, the chemicals damage the protective sheaths that surround nerve cells. The disease is passed down through families (inherited). You must get a copy of the defective gene from both your parents to have the disease.
Diagnosis: Tests that may be done include: Blood or skin culture to look for low arylsulfatase A activity, Blood test to look for low arylsulfatase A enzyme levels, CT scan, DNA testing for the ARSA gene, MRI, Nerve biopsy, Nerve signalling studies, Urinalysis, Urine chemistry.
Treatment: There is no cure for MLD. Care focuses on treating the symptoms and preserving the patient's quality of life with physical and occupational therapy.
We describe a 16-year-old boy with juvenile metachromatic leukodystrophy who was treated with bone marrow transplantation. Follow-up over 8 years showed no increase in symptoms, no progression of neurological signs, and no neuropsychological deterioration. We conclude that bone marrow transplantation may increase brain levels of arylsulfatase A enough to prevent deterioration in patients with juvenile metachromatic leukodystrophy.