Frequently
Asked Questions
Definition
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
[Return to top of page] What
are Mucopolysaccharide diseases?
These
rare metabolic diseases are refered to as MPS I-VII or more commonly
by the name of the doctor who first described the condition.
These commonly
include - Hurler
- Scheie
- Hunter
- Sanfilippo
- Morquio
- Maroteaux Lamy
- Sly
Also included are the Mucolipidoses, other 'storage diseases'
and the following conditions which are similar to Mucopolysaccharide:-
- MLI Neuramidase Deficiency
- MLII I-Cell Disease
- MLIII Pseudo Hurler Polydystrophy
- MLIV / Sialidosis / Fucosidosis
- Mannosidosis / Sialic Acid Storage Disease
- Multiple Sulphatase Deficiency
- Aspartylglycosaminuria
- Winchester Syndrome
[Return to top of page] What causes these
diseases? There is a continuous process in the body of replacing used materials
and breaking them down for disposal. Children born with a Mucopolysaccharide
or related disease are unable to produce one of the enzymes essential
for this process. If even one enzyme is missing, the cycle is interrupted.
Used materials cannot be broken down and remain stored in the cells
of the body. 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 the years go by.
[Return to top of page] How
are they inherited? We all have genes inherited from our parents, which control our
height, eye colour, hair colour etc. Some genes we inherit are recessive,
that is to say, we carry the gene but it does not have any effect
on our characteristics or development. The Mucopolysaccharide diseases
are caused by such recessive genes. In all MPS and related disorders
except Hunter Disease, both men and women can be carriers.
[Return to top of page] What
are the effects of the disease? The effects vary from one disease to another. Some sufferers may
be mildly affected, but for many the diseases cause severe disabilities.
In most cases growth is restricted. Some diseases cause progressive
mental as well as physical handicap. Those diseases causing severe
mental handicap may also lead to death in childhood.
[Return to top of page] Is
there a cure? At present there is no cure. Research funded by the MPS Society on Gene
Therapy for Hurler Disease was carried out on three patients in 1998.
More recently the development of 'Enzyme Replacement Therapy' (ERT) for
Fabry and MPS I has been approved as a treatment and ERT for MPS II and
MPS VI has reached the clinical trial stage for MPS Type I. This is being
developed jointly by Biomarin and Genzyme pharmaceutical companies. Early
indications from the clinical trials are promising, but there are still
serious obstacles to overcome if there is to be enzyme replacement therapy
for all types of Mucopolysaccharide and related diseases.
[Return to top of page]
The
Family of MPS Diseases
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