arylsulfatase A deficiency

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met·a·chro·mat·ic leu·ko·dys·tro·phy

[MIM*250100, MIM*249900]
a metabolic disorder, with onset usually in the second year of life and death often before age 5 years, with loss of myelin and accumulation of metachromatic lipids (galactosyl sulfatidates) in the white matter of the central and peripheral nervous systems leading to motor symptoms, paralysis, convulsions, and progressive cerebral deterioration. Autosomal recessive inheritance caused by mutation in either the arylsulfatase A gene (ARSA) on 22q or the prosaposin gene (PSAP) on 10q. There is a dominant form occurring in adults [MIM*156310].

metachromatic leukodystrophy

An autosomal recessive lysosomal storage disease (OMIM:250100) caused by arylsulfatase A deficiency, characterised by an accumulation of sulphated sphingolipid (cerebroside-3-sulfate) in neural and non-neural tissues, and a diffuse loss of myelin in the CNS.

Clinical findings
Onset by age two, death by age five, with upper and lower motor neuron disease, decreased nerve conduction, spasms, ataxia, oculomotor paralysis, bulbar palsy, blindness, deafness, and dementia.

Molecular pathology
Defects in ARSA on chromosome 22q13.31-qter, which encodes arylsulfatase A, causes metachromatic leukodystrophy.

All therapies are experimental; none are effective.

Universally fatal.

arylsulfatase A deficiency

Metachromatic leukodystrophy, see there.


a group of enzymes active in the hydrolysis of sulfates and the metabolism of mucopolysaccharides; found in liver, pancreas, kidneys and immature monocytes. Several species of molluscs and Aerobacter spp. serve as commercial sources of the enzyme which is used in analytic endocrinology.

arylsulfatase A deficiency
see metachromatic leukodystrophy.
arylsulfatase B deficiency
is the cause of mucopolysaccharidosis VI which occurs in humans and cats. Called also Maroteaux-Lamy syndrome.