Mucopolysaccharidosis VII

Understanding Mucopolysaccharidosis VII

Mucopolysaccharidosis VII (MPS VII, Sly Syndrome) is an inherited enzyme deficiency disorder. It is characterized by skeletal and connective tissue abnormalities and neurological deterioration. It is caused by a lack of the enzyme beta-glucuronidase. Symptoms can be severe and may include cloudy corneas, hearing loss, carpal tunnel syndrome, hernias, skeletal abnormalities, joint stiffness, short stature and central nervous system involvement, among others. Treatment includes enzyme replacement therapy, physical and occupational therapy, and orthopedic care.

Signs and Symptoms

The clinical manifestations of MPS VII are varied and can include the following:

  • cloudy cornea (corneal opacity)
  • hearing loss
  • carpal tunnel syndrome
  • joint stiffness
  • hernias
  • skeletal abnormalities
  • short stature
  • central nervous system involvement
  • intellectual disability
  • cardiac involvement

The severity and progression of MPS VII vary widely from person to person. Some individuals may belong to a milder group of patients who may retain their vision, hearing, mobility, and cognitive function less affected by the disease, whereas, some patients may quickly progress with severe and extensive disease features.


The diagnosis of MPS VII is suspected in individuals who have any of the physical findings or complications associated with the disorder. Diagnosis of MPS VII is typically made through a combination of clinical findings, urine and blood tests, and specialized medical or genetic testing (such as enzyme analysis). Molecular testing can also be done to identify the specific mutation causing MPS VII.


Treatment of MPS VII depends on the individual's symptoms and severity of the disorder. Treatment may include enzyme replacement therapy, physical and occupational therapy, orthopedic care, cochlear implant surgery, eye exams, and cardiac evaluations. Additionally, individuals with MPS VII may benefit from specialized education and social activities that are tailored to their individual needs. There is no cure for MPS VII, but early diagnosis and treatment may be beneficial.