Currently, there is no universal cure for mucopolysaccharidosis (MPS). However, several treatment options can manage symptoms, reduce certain disease complications, and improve quality of life. For selected MPS types, treatments may also slow disease progression.

Mucopolysaccharidosis is caused by deficiencies in specific enzymes needed to break down glycosaminoglycans (GAGs). These substances accumulate in different tissues and organs, potentially affecting the skeleton, heart, respiratory system, liver, and other parts of the body.
The treatment approach depends on the specific MPS type, disease severity, age at diagnosis, and organs affected.

1. Enzyme replacement therapy (ERT)
Enzyme replacement therapy involves administering a laboratory-produced version of the enzyme that is deficient in a particular MPS type.
ERT is available for several types, including MPS I, II, IVA, VI, and VII, depending on the country and product availability.
Potential benefits include:
– Improving endurance and physical function in some patients.
– Reducing liver and spleen enlargement.
– Improving certain respiratory symptoms.
– Reducing urinary GAG levels.
– Supporting quality of life and everyday functioning.
However, enzyme replacement therapy has important limitations. Many intravenously administered enzymes do not cross the blood–brain barrier in sufficient amounts to treat neurological disease effectively. Therefore, conventional ERT generally does not prevent or reverse the progressive neurological involvement associated with severe MPS I or MPS II.
ERT also does not correct the underlying genetic variant, and ongoing treatment is usually required.

2. Haematopoietic stem cell transplantation (HSCT)
Haematopoietic stem cell transplantation may be recommended for selected children with severe MPS I, particularly before significant neurological damage has occurred.
The transplanted donor cells can produce the enzyme that the patient lacks. This may help improve outcomes, including preserving cognitive function in appropriately selected patients.
However, transplantation carries significant risks, including serious infections, graft-versus-host disease, and treatment-related complications. It is not suitable for every patient and requires evaluation at an experienced specialist centre.
HSCT does not completely prevent all complications, particularly established skeletal abnormalities.

3. Supportive and multidisciplinary treatment
Supportive care is essential for people living with mucopolysaccharidosis, regardless of whether disease-specific treatment is available.
Management may involve:
– Cardiologists for heart valve and cardiac complications.
– Respiratory specialists for airway obstruction and breathing problems.
– Orthopaedic specialists for skeletal abnormalities.
– Physiotherapists for mobility and joint function.
– Audiologists and ophthalmologists for hearing and vision problems.
– Developmental and neurological specialists when needed.
Regular monitoring helps identify complications and guide treatment.