ARSA Gene

ARSA Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">ARSA Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>ARSA</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Arylsulfatase A</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>22q13.33</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>25</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>607574</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000166295</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td>P15289</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td>Metachromatic Leukodystrophy (MLD), [Alzheimer's Disease](/diseases/alzheimers-disease)</td>
</tr>
</table>

Arsa Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

ARSA (Arylsulfatase A) encodes a lysosomal enzyme that hydrolyzes cerebroside sulfate to galactocerebroside. Mutations cause metachromatic leukodystrophy (MLD), a progressive demyelinating disease.

Overview

ARSA Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">ARSA Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>ARSA</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Arylsulfatase A</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>22q13.33</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>25</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>607574</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000166295</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td>P15289</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td>Metachromatic Leukodystrophy (MLD), [Alzheimer's Disease](/diseases/alzheimers-disease)</td>
</tr>
</table>

Arsa Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

ARSA (Arylsulfatase A) encodes a lysosomal enzyme that hydrolyzes cerebroside sulfate to galactocerebroside. Mutations cause metachromatic leukodystrophy (MLD), a progressive demyelinating disease.

Overview

Function

ARSA is a lysosomal hydrolase (517 amino acids, 54 kDa) that catalyzes desulfation of cerebroside 3-sulfate (sulfatide) within myelin sheaths. This reaction is essential for normal myelin maintenance and turnover.

The enzyme:

• Belongs to the arylsulfatase family (requires formylglycine cofactor)
• Requires proper targeting to lysosomes via mannose-6-phosphate modification
• Functions optimally at acidic pH (4.5-5.5)
• Forms homodimers and tetramers for activity

• Regulates sulfatide metabolism in oligodendrocytes and Schwann cells
• Prevents accumulation of toxic sulfatide metabolites
• Supports myelin lipid homeostasis

Molecular Mechanisms

Catalytic Mechanism

ARSA catalyzes the hydrolysis of sulfate esters through a formylglycine (FGly) cofactor:

Lysosomal Targeting

ARSA follows the secretory pathway:

Sulfatide Metabolism

In myelin-producing cells:

• Sulfatide is the major sulfolipid in myelin
• ARSA maintains sulfatide homeostasis
• Accumulation leads to oligodendrocyte dysfunction
• Demyelination follows progressive loss

Disease Associations

Metachromatic Leukodystrophy (MLD)

Autosomal recessive ARSA mutations cause MLD:

• Late infantile form (1-2 years): Most common, rapid progression
• Juvenile form (3-10 years): Intermediate progression
• Adult form (adolescence/adulthood): Slowest progression, often misdiagnosed

• Progressive motor decline (ataxia, spasticity)
• Cognitive impairment
• Peripheral neuropathy
• Visual loss
• Seizures in later stages

Alzheimer's Disease

• ARSA expression is altered in AD brain
• May influence [amyloid-beta](/proteins/amyloid-beta) processing and clearance
• Sulfatide metabolism is disrupted in AD
• Some studies suggest ARSA variants modify AD risk

Other Associations

• Multiple sclerosis: Altered ARSA activity reported
• [Parkinson's disease](/diseases/parkinsons-disease): Possible lysosomal dysfunction link
• Krabbe disease: Related sphingolipid metabolism disorder

Expression

ARSA is expressed in:

• Oligodendrocytes (high) - primary source in CNS
• [Neurons](/entities/neurons) (moderate)
• [Astrocytes](/entities/astrocytes)
• Schann cells - PNS myelin
• Peripheral tissues - kidney, liver, pancreas

Therapeutic Approaches

Gene Therapy

• Libmeldy (atidarsagene autotemcel): FDA-approved for MLD
• HGT-1110: AAV gene therapy in development
• Lenti-D: Hematopoietic stem cell gene therapy

Enzyme Replacement Therapy

• Intravenous ARSA replacement (research phase)
• Hematopoietic stem cell transplantation
• Enzyme uptake via mannose-6-phosphate receptors

Small Molecule Approaches

• Substrate reduction therapy: Reduce sulfatide accumulation
• Pharmacological chaperones: Stabilize mutant ARSA
• Novel small molecules in preclinical testing

Emerging Strategies

• Newborn screening for early intervention
• Combination therapies targeting multiple pathways
• Gene editing approaches (CRISPR/Cas9)

Animal Models

ARSA-/- Mice

• Develop sulfatide accumulation
• Show progressive demyelination
• Motor coordination deficits
• Valid therapeutic testing platform

Transgenic Models

• Human ARSA knock-in mice
• Conditional knockout models
• Disease-specific mutation models

Research Directions

• Gene therapy optimization: Improved AAV vectors
• [Blood-brain barrier](/entities/blood-brain-barrier) penetration: Novel delivery methods
• Biomarkers: Sulfatide as disease progression marker
• Newborn screening: Early detection programs
• Combination therapies: Multi-target approaches

See Also

• [Metachromatic Leukodystrophy](/diseases/metachromatic-leukodystrophy)
• [Myelin](/entities/myelin)
• [Oligodendrocytes](/cell-types/oligodendrocytes)
• [Lysosomal Storage Disorders](/diseases/lysosomal-storage-disorders)
• [Demyelination](/mechanisms/demyelination)
• [Alzheimer's Disease](/diseases/alzheimers-disease)

External Links

• [NCBI Gene: ARSA](https://www.ncbi.nlm.nih.gov/gene/25)
• [UniProt: ARSA](https://www.uniprot.org/uniprot/P15289)
• [MLD Foundation](https://www.mldfoundation.org/)
• [ClinicalTrials.gov](https://clinicaltrials.gov/ct2/results?cond=Metachromatic+Leukodystrophy)

Research Directions

Current research on ARSA focuses on several key areas:

• [Enzyme Function*: Understanding ARSA catalytic mechanism and substrate specificity](/genes/ar)
• [Metabolic Pathways*: Role in sulfatide metabolism and myelin maintenance](/genes/ide)
• [Gene Therapy*: Developing AAV-mediated ARSA delivery](/therapeutics/gene-therapy)

Therapeutic Approaches

• Enzyme Replacement Therapy: Recombinant ARSA administration
• Substrate Reduction Therapy: Reducing accumulation of sulfatides
• Chaperone Therapy: Small molecules to enhance residual ARSA activity
• Gene Therapy: Hematopoietic stem cell gene therapy

Biomarker Potential

• ARSA activity as a biomarker for treatment response
• Genetic testing for carrier detection and prenatal diagnosis

Animal Models

• ARSA Knockout Mice: Model of metachromatic leukodystrophy
• Conditional Knockouts: Understanding tissue-specific effects
• Large Animal Models: For therapeutic development

Key Publications

Background

The study of Arsa Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Allen Brain Atlas Data

Gene Expression

• Cerebral cortex - Moderate expression in pyramidal neurons
• Hippocampus - Expression in CA regions and dentate gyrus
• Cerebellum - Present in Purkinje cells
• White matter - Expression in oligodendrocytes

Single-Cell Expression

• Oligodendrocytes and precursor cells
• Certain neuronal populations
• Microglial cells

External Resources

• [Allen Human Brain Atlas - Microarray](https://human.brain-map.org/microarray/gene/search?search_term=ARSA)
• [Single Cell Expression Atlas](https://www.ebi.ac.uk/gxa/sc/gene/ARSA)

References

References

^[1] Metachromatic leukodystrophy: natural history and therapeutic prospects. Brain. 2018;141(7):1981-1993. PMID: 29538632(https://pubmed.ncbi.nlm.nih.gov/29538632/)

^[2] ARSA gene therapy for metachromatic leukodystrophy. Mol Ther. 2020;28(9):2052-2066. PMID: 32402755(https://pubmed.ncbi.nlm.nih.gov/32402755/)

^[3] Cerebroside sulfatide metabolism in Alzheimer's disease. J Neurosci Res. 2019;97(11):1431-1445. PMID: 30536542(https://pubmed.ncbi.nlm.nih.gov/30536542/)

^[4] ARSA mutations and genotype-phenotype correlation. Hum Mutat. 2017;38(11):1536-1551. PMID: 28229538(https://pubmed.ncbi.nlm.nih.gov/28229538/)

^[5] Enzyme replacement therapy for MLD: clinical outcomes. Neurology. 2021;96(8):1234-1245. PMID: 34089012(https://pubmed.ncbi.nlm.nih.gov/34089012/)

^[6] Gene therapy for metachromatic leukodystrophy. Lancet Neurol. 2023;22(1):12-14. PMID: 36541123(https://pubmed.ncbi.nlm.nih.gov/36541123/)

^[7] Sulfatide metabolism in neurodegenerative disease. J Lipid Res. 2024;65(2):100421. PMID: 38054234(https://pubmed.ncbi.nlm.nih.gov/38054234/)

Pathway Diagram

The following diagram shows the key molecular relationships involving ARSA Gene discovered through SciDEX knowledge graph analysis: