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ARSB

arylsulfatase B

The ARSB gene encodes the arylsulfatase B enzyme, which plays a critical role in the breakdown of complex sugar molecules within cellular lysosomes. ARSB provides instructions for creating arylsulfatase B, an enzyme responsible for degrading glycosaminoglycans like dermatan sulfate and chondroitin sulfate.

Chromosome 5q14.1 Autosomal recessive HGNC:714 Tier C
ARSB 5q14.1 p arm q arm 5

ARSB is located on the long (q) arm of chromosome 5, at band 5q14.1. Arm ratio per GRCh38 - banding schematic.

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Clinical tests that include this

Carrier Screening panel
ARSB is 1 of 1,008 genes on this panel
Expanded carrier screening for recessive and X-linked conditions
Newborn Genetic Screening panel
ARSB is 1 of 258 genes on this panel
Genomic newborn screening for actionable paediatric conditions

Overview

The ARSB gene, also known as arylsulfatase B, provides the genetic blueprint for an enzyme called arylsulfatase B. This enzyme is essential for the normal functioning of lysosomes, which are cellular compartments responsible for recycling and digesting various molecules. Specifically, arylsulfatase B participates in the breakdown pathway of large sugar molecules known as glycosaminoglycans (GAGs).

What the gene does

The primary function of the ARSB gene product, arylsulfatase B, is to remove a chemical group called a sulfate from specific glycosaminoglycans (GAGs). This enzyme acts on dermatan sulfate and chondroitin sulfate, two types of GAGs that are important components of connective tissues. Arylsulfatase B is located within lysosomes, which are organelles within cells that act as the cell's waste disposal and recycling centres. By breaking down GAGs, the enzyme helps prevent their accumulation, which can otherwise disrupt cellular processes and lead to various health issues.

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Chromosome location

The ARSB gene is located on chromosome 5. Its specific chromosomal position is 5q14.1, which indicates it is found on the long (q) arm of chromosome 5, within region 1, band 4, sub-band 1.

Protein structure

The ARSB gene encodes a protein that is 533 amino acids long. Domain architecture has not been experimentally characterised in detail for this protein.

Key variants

Genetic variations, or variants, within the ARSB gene can alter the function of the arylsulfatase B enzyme. Many identified variants involve changes to single DNA building blocks (nucleotides). These changes can lead to a reduced or absent enzyme activity, affecting the cell's ability to properly break down glycosaminoglycans.

The table below shows the top 10 pathogenic or likely-pathogenic variants currently classified in ClinVar for ARSB.
View all on ClinVar →

Sample of pathogenic variants

10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.

Variant (HGVS) Protein change Classification Evidence Associated condition
c.1060_1061del
Deletion
 p.Leu354fs Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.1142+1G>A
single nucleotide variant
 - Pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.1143-1G>A
single nucleotide variant
 - Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.1314G>A
single nucleotide variant
 p.Trp438Ter Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.1325C>G
single nucleotide variant
 p.Thr442Arg Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.1350G>T
single nucleotide variant
 p.Trp450Cys Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.1539C>A
single nucleotide variant
 p.Tyr513Ter Pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.352_365dup
Duplication
 p.Pro123fs Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.359dup
Duplication
 p.Ser120fs Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6
c.982G>A
single nucleotide variant
 p.Gly328Arg Pathogenic/Likely pathogenic ★★☆☆ Mucopolysaccharidosis type 6

Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.

Associated conditions

Pathogenic variants in the ARSB gene are known to cause Mucopolysaccharidosis type VI, also referred to as Maroteaux-Lamy syndrome. This condition is an autosomal recessive lysosomal storage disorder, meaning an individual must inherit two copies of a pathogenic ARSB variant (one from each parent) to be affected. The severity of Mucopolysaccharidosis type VI can vary, although specific variants do not always directly predict a mild or severe outcome.

  • Mucopolysaccharidosis type VI (Maroteaux-Lamy)
    IEM
    AR
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Inheritance pattern

Conditions caused by pathogenic ARSB variants typically follow autosomal recessive inheritance.

♀ Carrier parent 1 altered copy ♂ Carrier parent 1 altered copy Affected Carrier Carrier Unaffected Affected Carrier Unaffected Circles = females · Squares = males

When both parents are carriers, each child has a 25% chance of being affected, 50% of being a carrier, and 25% of being unaffected.

Carrier frequency by population How common is heterozygous ARSB carrier status across ancestry groups?

UK clinical status

The ARSB gene is well-recognised in UK clinical genetics, featuring on several NHS Genomic Medicine Service national panels. These include panels for Foetal anomalies, Hydrocephalus, Intellectual disability, Lysosomal storage disorder, Mucopolysaccharidosis type VI, and Skeletal dysplasia, among others. Its presence on these panels highlights its clinical significance in diagnosing relevant conditions.

Green-listed
High evidence · clinically actionable in NHS testing
Included in NHS GMS signed-off panels
Fetal anomalies · R21 NHS GMS → Hydrocephalus · R86 NHS GMS → Likely inborn error of metabolism · R98 NHS GMS → Lysosomal storage disorder · R276 NHS GMS → Mucopolysaccharidosis type VI · R290 NHS GMS → Rare syndromic craniosynostosis or isolated multisuture synostosis · R100 NHS GMS → Skeletal dysplasia · R104 NHS GMS → DDG2P NHS GMS →
NHS Genomic Medicine Service Jeen carrier screening

Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory

Frequently asked questions

What is the main role of the ARSB gene?

The ARSB gene provides instructions for making an enzyme called arylsulfatase B. This enzyme is crucial for breaking down large sugar molecules called glycosaminoglycans (GAGs), specifically dermatan sulfate and chondroitin sulfate, within cellular lysosomes.

What happens if the ARSB gene doesn't work correctly?

If the ARSB gene is not functioning correctly, the arylsulfatase B enzyme may be deficient or absent. This leads to the accumulation of glycosaminoglycans within cells, which can cause a lysosomal storage disorder known as Mucopolysaccharidosis type VI.

How is Mucopolysaccharidosis type VI inherited?

Mucopolysaccharidosis type VI is inherited in an autosomal recessive pattern. This means an individual must inherit two altered copies of the ARSB gene, one from each parent, to develop the condition. People with only one altered copy are carriers and typically do not show symptoms.

References

  1. Tessitore A, Pirozzi M, Auricchio A. Abnormal autophagy, ubiquitination, inflammation and apoptosis are dependent upon lysosomal storage and are useful biomarkers of mucopolysaccharidosis VI. PathoGenetics. 2009. PMID: 19531206
  2. Clarke LA. The mucopolysaccharidoses: a success of molecular medicine. Expert reviews in molecular medicine. 2008. PMID: 18201392
  3. Garrido E, Cormand B, Hopwood JJ. Maroteaux-Lamy syndrome: functional characterization of pathogenic mutations and polymorphisms in the arylsulfatase B gene. Molecular genetics and metabolism. 2008. PMID: 18406185
  4. Karageorgos L, Brooks DA, Pollard A. Mutational analysis of 105 mucopolysaccharidosis type VI patients. Human mutation. 2007. PMID: 17458871
  5. Garrido E, Chabás A, Coll MJ. Identification of the molecular defects in Spanish and Argentinian mucopolysaccharidosis VI (Maroteaux-Lamy syndrome) patients, including 9 novel mutations. Molecular genetics and metabolism. 2007. PMID: 17643332
  6. Litjens T, Hopwood JJ. Mucopolysaccharidosis type VI: Structural and clinical implications of mutations in N-acetylgalactosamine-4-sulfatase. Human mutation. 2001. PMID: 11668612
Educational content. This page is not medical or genetic advice, is not individually reviewed by a clinician for each reader, and should not replace a consultation with a qualified healthcare professional or genetic counsellor. If you are considering genetic testing or acting on a test result, book a consultation.
Data sources Last updated 13 September 2026. Content compiled from HGNC · MedlinePlus Genetics · ClinGen · Genomics England PanelApp · NHS National Genomic Test Directory · ClinVar · UniProt · AlphaFold .