Decoding Mucopolysaccharidosis Type VI: A Comprehensive Guide to Understanding, Diagnosing, and Utilizing Genetic Testing

Expert Reviewed By: ⁠Dr. Brandon Colby MD

Mucopolysaccharidosis Type VI (MPS VI), also known as Maroteaux-Lamy syndrome, is a rare genetic disease that affects various parts of the body. This article will provide an in-depth understanding of MPS VI, including its clinical, diagnostic, and therapeutic aspects, as well as recent preclinical studies and the need for new biomarkers. Furthermore, we will discuss the use of genetic testing in managing the disease.

Understanding Mucopolysaccharidosis Type VI

MPS VI is a lysosomal storage disorder caused by a deficiency in the enzyme N-acetylgalactosamine 4-sulfatase (arylsulfatase B). This enzyme is responsible for breaking down large sugar molecules called glycosaminoglycans (GAGs). When the enzyme is deficient or not functioning correctly, GAGs accumulate in the body, leading to various symptoms and complications [1].

The severity of MPS VI can vary widely, with some individuals experiencing mild symptoms and others having life-threatening complications. Common symptoms include short stature, skeletal abnormalities, joint stiffness, heart and lung problems, vision and hearing impairment, and intellectual disability [1].

Diagnosing Mucopolysaccharidosis Type VI

Diagnosing MPS VI involves a combination of clinical examination, biochemical tests, and genetic testing. Biochemical tests measure the activity of the arylsulfatase B enzyme and the levels of GAGs in the body. Reduced enzyme activity and elevated GAG levels can suggest a diagnosis of MPS VI [1].

Genetic Testing for Mucopolysaccharidosis Type VI

Genetic testing is essential for confirming a diagnosis of MPS VI. The disease is caused by mutations in the ARSB gene, which provides instructions for producing the arylsulfatase B enzyme. By analyzing the DNA sequence of the ARSB gene, genetic testing can identify the specific mutations responsible for the enzyme deficiency [1].

Genetic testing can also be helpful in several other aspects of managing MPS VI, such as:

Carrier Testing and Prenatal Diagnosis

Since MPS VI is an autosomal recessive disorder, both parents must be carriers of a mutated ARSB gene to have an affected child. Carrier testing can help identify couples at risk of having a child with MPS VI. In addition, prenatal diagnosis through amniocentesis or chorionic villus sampling can determine if a fetus has inherited the disease-causing mutations from both parents [1].

Guiding Treatment Decisions

Genetic testing can provide information about the specific ARSB gene mutations, which may help predict the severity of the disease and guide treatment decisions. For example, some mutations are associated with a milder form of MPS VI, while others may lead to a more severe phenotype [1].

Treatment Options for Mucopolysaccharidosis Type VI

Currently, the primary treatment option for MPS VI is enzyme replacement therapy (ERT) with galsulfase, a recombinant form of the arylsulfatase B enzyme. ERT has been shown to improve several symptoms of MPS VI, such as endurance, growth, and joint mobility. However, its effectiveness in treating other aspects of the disease, such as bone and heart problems, remains unclear [3].

Other treatment options for MPS VI may include supportive therapies, such as physical therapy, occupational therapy, and pain management. In some cases, surgical interventions may be necessary to address skeletal abnormalities, heart problems, or airway obstruction [1].

Conclusion

Mucopolysaccharidosis Type VI is a complex genetic disease with varying symptoms and severity. Understanding the disease, obtaining an accurate diagnosis, and utilizing genetic testing can help guide treatment decisions and improve the quality of life for affected individuals. Further research is needed to develop new biomarkers and therapies for MPS VI, as well as to better understand the long-term outcomes of current treatment options.

About The Expert Reviewer

Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of  and the author of ⁠⁠Outsmart Your Genes.

Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (⁠⁠ACMG), an Associate of the American College of Preventive Medicine (⁠⁠ACPM), and a member of the National Society of Genetic Counselors (⁠NSGC)