MPS VI – Maroteaux Lamy disease

For more information please download our Guide to MPS VI.

What is MPS VI?

Maroteaux-Lamy disease, also known as MPS VI, is one of the rarer Mucopolysaccharide diseases. It takes its name from two French doctors, Dr Maroteaux and Dr Lamy, who first described the condition in 1963.

Although there is no cure for MPS diseases, there are ways of managing and treating the problems they cause.

What causes this disease?

Mucopolysaccharides are long chains of sugar molecule used in the building of connective tissues in the body.

  • “saccharide” is a general term for a sugar molecule (think of saccharin)
  • “poly” means many
  • “muco” refers to the thick jelly-like consistency of the molecules

Children and adults with MPS VI are missing an enzyme which is essential in cutting up the Mucopolysaccharide Dermatan Sulphate. The incompletely broken down Dermatan Sulphate remains stored inside a part of the cell called the lysosome. The lysosomes become swollen and disrupt cell functioning causing progressive damage.

Babies may show little sign of the disease but symptoms start to appear as more and more cells become damaged by the accumulation of Mucopolysaccharides.

Does MPS VI affect individuals differently?

The disease varies enormously in the severity of the problems it causes. It is important to remember this if you are a parent of a newly diagnosed child.

How common is this disease?

The MPS Society, which co-ordinates the Registry for MPS and Related Diseases, has shown that between 1989 and 1999, 9 babies with MPS VI were born in the UK.

How is the disease inherited?

MPS VI is an autosomal recessive disease whereby both parents must carry the same defective gene and each pass this same defective gene to their child. Where both parents are carriers of the MPS VI gene there is a 25% (1:4) chance of having an affected child with each pregnancy.

There is a 50% (1:2) chance of a child receiving only one copy of the defective gene and therefore being a carrier. A carrier will not be affected but can pass the defective gene to his/her offspring. The remaining 25% (1:4) will be neither affected nor a carrier. Using information from an affected individual’s DNA, it may be possible to determine whether brothers and sisters are carriers of, or are affected by MPS VI.

There is a more detailed explanation of this complex subject in the booklet on inheritance available from the MPS Society.

Treatment options

For available treatment options and the latest news and information on research, therapies and clinical trials please visit our treatment section.