Metachromatic leukodystrophy

From Biology-Online Dictionary | Biology-Online Dictionary



A type of sphingolipidosis that is often caused by a deficiency in arylsulfatase A or prosaposin resulting in the accumulation of sulfatide compounds in neural tissue, and thereby leads to demyelination


Sphingolipidosis is a collective term for the various metabolic disorders due to an abnormal sphingolipid metabolism. One of them is the metachromatic leukodystrophy.

Metachromatic leukodystrophy is a type of lysosomal disease, particularly sphingolipidosis. A defect in the gene coding for arylsulfatase A or prosaposin results in this condition. Without sufficient arylsulfatase A or prosaposin, sulfatide compounds (galactosyl sulfatidates) accumulate in the lysosomes in the cells of neural tissue. This leads to the demyelination of the central nervous system and the peripheral nervous system. The development of the myelin (a fatty covering around the nerve fibers) is affected. Other symptoms associated with metachromatic leukodystrophy are motor dynsfunction, ataxia, seizures, hypoflexia, and mental retardation.

Metachromatic leukodystrophy may be inherited in an autosomal recessive pattern. It is usually associated with mutation in ARSA gene on chromosome 22q or in PSAP gene on chromosome 10q. Defective ARSA gene is more commonly associated with metachromatic leukodystrophy than the PSAP gene defect.


  • MLD


  • arylsulfatase A deficiency
  • sulfatide lipidosis

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