If you or your child has been diagnosed with any of the 25 rare lysosomal storage diseases that we support

you can become a member of the MPS Society for free. Take a look at our Support section for more information on the different ways that we can help, from care plans to advice on education and independent living

The MPS Society’s aims are:

To support families and carers and ensure all individuals with MPS and related diseases have access to best practice in diagnosis, treatment and care.

To fund and promote research into the causes, effects and treatments of these diseases.

To increase public awareness of these rare conditions and to campaign for change – to improve the lives of children, adults and their families for the future.

The Society’s research objective

is to promote and support research into MPS and related diseases.

Its purpose is to play a leading role with clinicians, scientists and academics in initiating and funding innovative research projects.

Current treatments are available today thanks in part to funding from the MPS Society. At our 2015 Conference alone we presented cheques amounting to £124,000 to ground-breaking research projects.

MPS and related diseases


Mucopolysaccharide and related Lysomal Storage Diseases are individually rare; cumulatively affecting 1:25,000 live births. One baby born every eight days will be diagnosed with an MPS or related disease. These multi-organ storage diseases cause progressive physical disability and, in many cases, severe degenerative mental deterioration resulting in death in childhood.

Definition of MPS

Mucopolysaccharides are long molecular chains of sugar. They are used by the body in the building of connective tissues. The word ‘mucopolysaccharide’ can be broken down as follows: ‘muco’ refers to the thick jelly-like consistency of the molecules ‘poly’ means many ‘saccharide’ is a general term for a sugar molecule.

What are MPS and related diseases?

Mucopolysaccharide (MPS) and related diseases are Lysosomal Storage Diseases. These are rare, life-limiting, progressive, genetic conditions caused by the shortage of a particular enzyme.

MPS diseases are caused by a missing enzyme which means that the body can’t break down (metabolise) certain molecules called GAGs (Glycosaminoglycans). GAGs are structural molecules that are integral to connective tissues such as cartilage, tendons and other tissues in the body. They accumulate in cells in tiny structures called lysosomes. Without essential enzymes to break down, recycle and build new mucopolysaccharides they continue to be stored inside the lysosome. This causes the lysosome to swell and disrupts cell functioning. These are multi-organ storage diseases which cause progressive physical disability and in many cases, severe neurological deterioration and can result in death in childhood.


Babies may show no sign of the disease but as more and more cells become damaged by the storage of used material, symptoms begin to appear. Sadly these are progressive diseases which lead to an increase in problems as time goes by which usually affect any or all of the major organs including heart, liver, kidneys and also the bones, eyes and skin and can lead to increasing neurological deterioration.


MPS and related diseases are inherited conditions. The majority of types are inherited by autosomal recessive transmission. That means that if both of your parents are carriers, you have a one in four chance of having the disease.


Currently, although there is no cure, Enzyme Replacement Therapy (ERT) and Haematopoietic Stem Cell Transplant (HSCT) are available to treat a few types of MPS and related diseases although for the majority there is only palliative treatment and care.

The disease types

The MPS Society supports 25 MPS and related diseases. These rare Lysosomal Storage Diseases are referred to as MPS I-VII or more commonly by the name of the doctor who first described the condition. These commonly include:

  • MPS I – Hurler, Hurler Scheie and Scheie
  • MPS II – Hunter
  • MPS III – Sanfilippo
  • MPS IVA – Morquio
  • MPS VI – Maroteaux-Lamy
  • MPS VII – Sly
  • MPS IX – Natowicz

Included also are the Mucolipidoses, other ‘storage diseases’ and the following conditions which are similar to Mucopolysaccharide Diseases:

  • Aspartylglycosaminuria (AGU)
  • Fabry
  • Fucosidosis
  • Geleo Physic Dysplasia
  • GM-1 Gangliosidosis
  • Lysosomal Acid Lipase Deficiency 
  • Mannosidosis
  • Metachromatic Leukodystrophy
  • ML I – Neuramidase Deficiency
  • ML II – I-Cell Disease
  • ML III – Pseudo Hurler Polydystrophy
  • ML IV
  • Multiple Sulfatase Deficiency
  • Sialic Acid Storage Disease
  • Sialidosis
  • Winchester


Since 1980 the Society has maintained a research database to identify the incidence of Mucopolysaccharide and related diseases in the United Kingdom. In the period of 1974 to 1991 there have been 13,820,825 children born in the UK. These figures represent a mean annual birth rate of 737,823. In the same period a minimum incidence of 511 diagnoses of MPS diseases were recorded representing a mean annual birth rate of 28.4. This represents our overall minimum incidence of MPS and related diseases of 1:26,000, with specific incidences as follows: Hurler: 1:115,000 Hunter: 1:166,000 Sanfilippo: 1:89,000 Morquio: 1:220,000

MPS diseases

MPS diseases Mucopolysaccharide diseases are rare Lysosomal Storage Diseases, sometimes referred to as MPS I-VII, or more commonly by the name of the doctor who first described the condition. These include: MPS I – Hurler, Hurler Scheie and Scheie MPS II –

Disease factsheets

Guides and factsheets These factsheets provide further information about each of the MPS and related diseases: Aspartylglycosaminura (AGU) Fabry Fabry disease in the family Fucosidosis (Alpha) Mannosidosis (Beta) Mannosidosis Metachromatic Leukodystrophy (MLD) ML II ML III ML IV The Burden


Overview of Fabry The MPS Society supports those suffering with Fabry disease, a rare lysosomal storage disorder. For more information please download our Guide to Fabry and Fabry Disease in the Family. Fabry Disease, also known as Anderson-Fabry Disease, is closely related to

Related diseases

Related diseases The MPS Society supports 25 MPS and related diseases including the Mucolipidoses, other ‘storage diseases’ and the following conditions which are similar to Mucopolysaccharide Diseases: Aspartylglycosaminuria (AGU) Fucosidosis Geleo Physic Dysplasia GM-1 Gangliosidosis Lysosomal Acid Lipase Deficiency Mannosidosis Metachromatic