Mucopolysaccharidosis Type VI

Mucopolysaccharidosis Type VI, also known as MPS VI or Maroteaux-Lamy syndrome, is a rare genetic disorder that affects the body’s ability to break down certain complex sugars called mucopolysaccharides. In this simplified guide, we’ll provide you with a clear understanding of MPS VI, including its types, causes, symptoms, diagnostic tests, treatment options, and available drugs.

Types of MPS VI:

MPS VI can be classified into several subtypes, but the most common type is the classic form. The different types can vary in their severity and specific symptoms, but they all share the same underlying cause: a deficiency of the enzyme arylsulfatase B. This enzyme is responsible for breaking down mucopolysaccharides in the body.

Causes of MPS VI:

MPS VI is a genetic disorder caused by mutations in the ARSB gene. These mutations lead to a deficiency in the arylsulfatase B enzyme, which is essential for breaking down mucopolysaccharides in the body. When this enzyme is lacking, mucopolysaccharides build up in various tissues and organs, causing MPS VI symptoms.

Symptoms of MPS VI:

MPS VI can present a wide range of symptoms, which can vary in severity from person to person. Common symptoms include:

1. Facial Features: Individuals with MPS VI may have coarse facial features, including a flat nose bridge and a protruding tongue.
2. Skeletal Abnormalities: Bone and joint problems are common in MPS VI, leading to short stature, joint stiffness, and bone deformities.
3. Organ Enlargement: Organs such as the liver and spleen may become enlarged.
4. Heart and Respiratory Issues: MPS VI can affect the heart and respiratory system, leading to problems like heart valve disease and breathing difficulties.
5. Vision and Hearing Problems: Individuals with MPS VI may experience vision and hearing impairment over time.
6. Cognitive Impairment: Some individuals with MPS VI may also have cognitive and developmental delays.
7. Hernias: Hernias are more common in people with MPS VI due to connective tissue problems.
8. Corneal Clouding: The corneas of the eyes may become cloudy, affecting vision.

Diagnostic Tests for MPS VI:

Diagnosing MPS VI typically involves a combination of the following tests:

1. Enzyme Activity Assay: A blood or urine test to measure the activity of arylsulfatase B enzyme.
2. Genetic Testing: DNA testing to identify mutations in the ARSB gene.
3. Physical Examination: Evaluation of physical features and symptoms associated with MPS VI.
4. X-rays and Imaging: Radiological tests to assess skeletal and organ abnormalities.
5. Urinalysis: Examination of urine to detect elevated levels of mucopolysaccharides.
6. Echocardiogram: A heart ultrasound to check for heart valve problems.

Treatment for MPS VI:

While there is no cure for MPS VI, there are treatment options to manage its symptoms and improve the quality of life for individuals with the condition:

1. Enzyme Replacement Therapy (ERT): ERT involves regular infusions of the missing arylsulfatase B enzyme. This therapy can help reduce symptoms and slow down the progression of the disease.
2. Physical and Occupational Therapy: These therapies can help individuals manage joint stiffness, improve mobility, and maintain independence.
3. Surgical Interventions: Some MPS VI-related issues, such as hernias or joint deformities, may require surgical correction.
4. Medications: Pain medications, anti-inflammatory drugs, and medications to manage heart-related symptoms may be prescribed.
5. Hearing and Vision Aids: Devices like hearing aids and glasses can help manage sensory impairments.

Drugs for MPS VI:

1. Naglazyme (galsulfase): Naglazyme is the FDA-approved enzyme replacement therapy for MPS VI, delivered through regular intravenous infusions.
2. Anti-Inflammatory Medications: Drugs like ibuprofen or steroids may be prescribed to manage joint pain and inflammation.
3. Pain Management Medications: Depending on the severity of pain, over-the-counter or prescription pain relievers may be used.
4. Heart Medications: Medications like ACE inhibitors or beta-blockers may be prescribed to manage heart-related issues.

In conclusion, MPS VI is a rare genetic disorder caused by a deficiency of the arylsulfatase B enzyme, leading to the buildup of mucopolysaccharides in the body. Symptoms vary but can include facial features, skeletal abnormalities, organ enlargement, and more. Diagnosis involves enzyme activity assays, genetic testing, and physical examinations, while treatment options include enzyme replacement therapy, physical therapy, and medications to manage symptoms and improve the quality of life for individuals with MPS VI. While there is no cure, early diagnosis and appropriate treatment can make a significant difference in managing the condition and enhancing the lives of those affected.