ARSA

The protein encoded by this gene hydrolyzes cerebroside sulfate to cerebroside and sulfate. Defects in this gene lead to metachromatic leucodystrophy (MLD), a progressive demyelination disease which results in a variety of neurological symptoms and ultimately death. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Dec 2010]

Arylsulfatase A

Hydrolyzes cerebroside sulfate.

Glycosphingolipid metabolic process Source: Reactome
Neutrophil degranulation Source: Reactome

Lysosome; Endoplasmic reticulum

Metachromatic leukodystrophy (MLD): An autosomal recessive disease caused by abnormal intralysosomal accumulation of cerebroside-3-sulfate in central and peripheral nervous systems, as well as other organs. MLD is clinically characterized by leukodystrophy, progressive demyelination and a variety of neurological symptoms, including gait disturbances, ataxias, optical atrophy, dementia, seizures, and spastic tetraparesis. Decreased arylsulfatase A activity is detected in urine, leukocytes, and fibroblasts of affected individuals. Several forms of the disease can be distinguished according to the age at onset and disease severity: late infantile, juvenile and adult forms, partial cerebroside sulfate deficiency, and pseudoarylsulfatase A deficiency. Individuals with pseudoarylsulfatase A deficiency have low arylsulfatase A activity but lack neurological manifestations and are apparently healthy.
Multiple sulfatase deficiency (MSD): The protein represented in this entry is involved in disease pathogenesis. Arylsulfatase A activity is impaired in multiple sulfatase deficiency due to mutations in SUMF1 (PubMed:15146462). SUMF1 mutations result in defective post-translational modification of ARSA at residue Cys-69 that is not converted to 3-oxoalanine (PubMed:7628016). A clinically and biochemically heterogeneous disorder caused by the simultaneous impairment of all sulfatases, due to defective post-translational modification and activation. It combines features of individual sulfatase deficiencies such as metachromatic leukodystrophy, mucopolysaccharidosis, chondrodysplasia punctata, hydrocephalus, ichthyosis, neurologic deterioration and developmental delay.

The conversion to 3-oxoalanine (also known as C-formylglycine, FGly), of a serine or cysteine residue in prokaryotes and of a cysteine residue in eukaryotes, is critical for catalytic activity. This post-translational modification is severely defective in multiple sulfatase deficiency (MSD).