Q: What are MPS and related diseases?
A: Mucopolysaccharidoses (MPS) and related diseases are genetic lysosomal storage diseases (LSD) caused by the body’s inability to produce specific enzymes. Normally, the body uses enzymes to break down and recycle materials in cells. In individuals with MPS and related diseases, the missing or insufficient enzyme prevents the proper recycling process, resulting in the storage of materials in virtually every cell of the body. As a result, cells do not perform properly and may cause progressive damage throughout the body, including the heart, bones, joints, respiratory system and central nervous system.
While the disease may not be apparent at birth, signs and symptoms develop with age as more cells become damaged by the accumulation of cell materials. There is an estimate in the United States that 1 in 25,000 births will result in some form of MPS.
Q: What are the major characteristics of MPS and related diseases?
A: While the symptoms of the diseases may vary from one syndrome to another, there are similarities. Affected individuals may have mental retardation, cloudy corneas, short stature, stiff joints, incontinence, speech and hearing impairment, chronic runny nose, hernia, heart disease, hyperactivity, depression, pain, impulsive behavioral issues and a dramatically shortened life span.
Q: What is MPS III?
A: MPS III is a type of MPS known as Sanfilippo syndrome. Dr. Sylvester Sanfilippo was one of the doctors in the United States who described the condition in 1963.
To date, four different enzyme deficiencies have been found to cause MPS III syndrome, and therefore the condition is described as type A, B, C, or D. There is usually very little difference between the four types of the disease, but there are some very mild cases of the B form where the affected individuals have remained relatively healthy into adult life.
Q: How is MPS III inherited?
A: We all have genes inherited from our parents which control whether we are tall, short, fair, etc. Some genes we inherit are "recessive", that is to say we carry the gene but it does not have any affect on our development. MPS III is caused by a recessive gene. If the adult carrying the abnormal gene marries another carrier there will be a one in four chance with every pregnancy that the child will inherit the defective gene from each parent and will be affected with the disorder. There is a two in three chance that unaffected brothers and sisters of MPS III patients will be carriers. They can be reassured; however, as the disease is so rare, the chance of marrying another carrier is very slight.
Q: Is there a cure?
A: At present there are no cures for any of the MPS diseases. Various experimental methods have been used to try to replace the missing enzyme, but none so far have been of any significant long-term benefit. Bone marrow transplants have been tried on MPS III patients, but with disappointing results. Because the experimental methods are ‘experimental’, insurance does not cover these ‘methods’ of treatment.
Q. How Does the Disease Progress?
A: The disease will affect children differently, and its progress will be much faster in some individuals than in others. Change will usually be very gradual, and therefore, easier to adjust to.
The disease tends to have three main stages:
1. During the child's pre-school years may be a very frustrating stage one for the parents. They begin to worry as their child starts to lag behind their friends' children in development, and they may feel they are being blamed for the child's overactive and difficult behavior.
The diagnosis is often made very late as some children do not look abnormal, and their symptoms are among the most common seen in all children. The doctor has to be perceptive enough to recognize that something serious is wrong and ask for urine and blood tests to help reach a diagnosis. It is not unusual for families to have one or more affected children before the diagnosis is established.
2. The second phase of the disease is characterized by extremely active, restless and often very difficult behavior. Some children sleep very little at night. Many will be into everything. Many like to chew; hands, clothes or anything they can get hold of.
Sadly, language and understanding will gradually be lost and parents may find it hard not being able to have a conversation with their child. Many will find other ways of communicating. Some children never become toilet trained, and those who do will eventually lose the ability.
3. In the third phase of the disorder children with MPS III begin to slow down. They become unsteady on their feet, tending to fall frequently as they walk or run. Eventually they lose the ability to walk. Life may be more peaceful in some ways, but parents will need help with the physically tiring task of caring for an immobile child or teenager.
Q. Is research helping today's families?
A: Although there are currently no cures for MPS and related diseases, research is making great strides. Carrier detection, the development of replacement enzymes, and the possibility of gene therapy, are among today’s research themes and treatment options. Bone marrow transplantation has been considered successful for many, though relatively few individuals qualify for this high-risk procedure. We’ve made major advancements in research thanks to the fundraising efforts of the National MPS Society, its members, and friends.
Other links/sites to check out:
www.mpssociety.org The MPS Society's official website. The MPS Society is a great national resource for information, support and financial assistance to families dealing with MPS diseases.
www.teamsanfilippo.org A group of families joined together to raise funds and further research into viable treatments for children suffering with Sanfilippo Syndrome.
www.jonahsjustbegun.org One family in New York that has created a foundation to fund research and has collaborated with doctors and other parents in Europe as well.
www.bensdream.org Another family organization determined to fund research to find a treatment/cure for Sanfilippo Syndrome.