Mucopolysaccharidosis Type VI (Maroteaux-Lamy Syndrome)
A rare inherited enzyme deficiency causing progressive accumulation of dermatan sulfate, leading to multisystem skeletal, cardiac, and respiratory disease, with intelligence typically preserved. Early enzyme replacement therapy can meaningfully change the disease course.
- Enzyme Replacement Therapy
- Stem Cell Transplant Access
- Multidisciplinary Specialist Coordination
- Estimated Incidence
- ~1 in 250,000–300,000 births
- Inheritance Pattern
- Autosomal Recessive (ARSB gene)
- Severity Spectrum
- Rapidly to slowly progressing forms
- Therapy Access
- Galsulfase ERT, Stem Cell Transplant
Condition Overview
Mucopolysaccharidosis type VI (MPS VI), known as Maroteaux-Lamy syndrome, is a rare inherited lysosomal storage disorder caused by deficiency of the enzyme arylsulfatase B (also called N-acetylgalactosamine-4-sulfatase). This deficiency leads to progressive accumulation of dermatan sulfate in tissues throughout the body, affecting the skeleton, joints, heart valves, cornea, airway, and liver and spleen.
A distinguishing feature of MPS VI compared to several other MPS types is that intelligence is typically preserved, even though somatic disease can be severe. The condition spans a clinical spectrum from a rapidly progressing form with onset in early childhood to a more slowly progressing, attenuated form that becomes apparent later in life.
Because disease severity and progression rate vary widely, early diagnosis and access to enzyme replacement therapy allow treatment to begin before significant irreversible skeletal and cardiac changes occur.
Types and Subtypes
MPS VI is classified along a clinical spectrum based on rate of disease progression, rather than as fully distinct subtypes.
Symptoms and Signs
Symptom severity and timing vary along the MPS VI spectrum, but most individuals develop a combination of skeletal, cardiac, respiratory, and ocular findings over time, with cognitive development remaining typically normal.
Causes and Risk Factors
MPS VI is caused by mutations in the ARSB gene, which provides instructions for producing arylsulfatase B, an enzyme required to break down dermatan sulfate. Reduced or absent enzyme activity allows dermatan sulfate to accumulate progressively in cells and tissues.
Diagnosis and Investigations
Diagnosis combines clinical suspicion based on growth and skeletal findings with biochemical and genetic confirmation.
Disease Phenotype and Severity Stratification
MPS VI does not use a tumor-staging framework. Disease is classified along a severity spectrum based on rate of progression, which guides treatment urgency and intensity of monitoring.
Standard Treatment Options
Treatment for MPS VI combines enzyme replacement therapy to reduce dermatan sulfate accumulation with coordinated multidisciplinary management of affected organ systems.
Advanced & Emerging Therapies
Beyond standard enzyme replacement therapy, several approaches are being studied to further improve outcomes for individuals with MPS VI, particularly for the rapidly progressing form.
Enzyme Replacement Therapy
Galsulfase (recombinant arylsulfatase B)
Approved intravenous enzyme replacement that reduces dermatan sulfate storage and has demonstrated improvements in endurance testing and organ size.
Cellular Therapy
Hematopoietic stem cell transplant
An option in some cases of the rapidly progressing form, particularly when diagnosed early, though enzyme replacement therapy is more commonly used as first-line treatment.
Gene Therapy
Investigational gene therapy approaches
Early-stage gene-addition strategies for ARSB deficiency are being explored as a potential long-term alternative to repeated enzyme infusions.
Targeted
Optimized surgical and anesthesia protocols
Refined approaches to airway and spine management have improved the safety of procedures in individuals with MPS VI.
Biomarkers & Precision Diagnostics
Biochemical and genetic markers guide diagnosis, severity classification, and treatment monitoring in MPS VI.
When a Second Opinion May Be Important
Because MPS VI management decisions, particularly around treatment timing and surgical planning, can be complex, a specialist second opinion is often valuable at key points.
Clinical Trials and Research
Prognosis and Key Outcome Factors
Outcomes in MPS VI vary with disease severity and how early treatment begins. With consistent enzyme replacement therapy and proactive multidisciplinary care, many individuals, particularly those with the slowly progressing form, experience meaningful improvement in mobility and quality of life.
Supportive Care and Living With MPS VI
Living with MPS VI involves ongoing coordination across multiple specialists, and supportive measures meaningfully improve daily function and quality of life.
How CancerFax Helps You Explore Treatment Options
CancerFax helps individuals and families affected by Maroteaux-Lamy syndrome access specialist review of medical reports, coordinate second opinions with metabolic disease specialists, and explore access to enzyme replacement therapy, transplant evaluation, and emerging research programs.
Get a free case reviewFrequently Asked Questions
MPS VI is a rare inherited disorder caused by deficiency of the enzyme arylsulfatase B, leading to progressive buildup of dermatan sulfate in tissues throughout the body, with intelligence typically preserved.
The rapidly progressing form presents in early childhood with significant growth restriction and faster organ involvement, while the slowly progressing form presents later with milder, more gradual disease.
Diagnosis combines urine dermatan sulfate testing, enzyme activity assays for arylsulfatase B, and confirmatory genetic testing of the ARSB gene.
There is no cure, but enzyme replacement therapy with galsulfase can substantially reduce disease burden, and stem cell transplant is an option in some cases of the rapidly progressing form.
Galsulfase is a recombinant form of arylsulfatase B given intravenously to reduce dermatan sulfate buildup in body tissues.
No. Intelligence is typically preserved in MPS VI, even when somatic disease, such as skeletal and cardiac involvement, is significant.
Yes. MPS VI follows an autosomal recessive inheritance pattern, meaning both parents must carry a mutated copy of the ARSB gene for a child to be affected.
Transplant may be considered in some cases of the rapidly progressing form, particularly when diagnosed early, though enzyme replacement therapy is more commonly used as first-line treatment.
Care typically involves metabolic genetics, cardiology, orthopedics, ENT, ophthalmology, and physical therapy working together.
Yes. CancerFax can help coordinate medical report review, connect individuals and families with metabolic disease specialists for a second opinion, and explore access to enzyme replacement therapy, transplant centers, and investigational gene therapy research, including cross-border coordination where appropriate.
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