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$Unique_ID{BRK03971}
$Pretitle{}
$Title{Maroteaux-Lamy Syndrome}
$Subject{Maroteaux-Lamy Syndrome Arylsulfatase-B Deficiency
Mucopolysaccharidosis VI MPS VI Polydystrophic Dwarfism MPS Disorder }
$Volume{}
$Log{}

Copyright (C) 1986, 1987, 1988, 1990 National Organization for Rare Disorders,
Inc.

283:
Maroteaux-Lamy Syndrome

** IMPORTANT **
It is possible the main title of the article (Maroteaux-Lamy Syndrome) is
not the name you expected.  Please check the SYNONYMS listing to find the
alternate names and disorder subdivisions covered by this article.

Synonyms

     Arylsulfatase-B Deficiency
     Mucopolysaccharidosis VI
     MPS VI
     Polydystrophic Dwarfism
     MPS Disorder

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.


Mucopolysaccharidoses are a group of rare genetic disorders caused by the
deficiency of one of ten specific lysosomal enzymes, resulting in an
inability to metabolize complex carbohydrates (mucopolysaccharides) into
simpler molecules.  The accumulation of these large, undegraded
mucopolysaccharides in the cells of the body causes a number of physical
symptoms and abnormalities.

Maroteaux-Lamy Syndrome (MPS Type VI) occurs in three types:  a classic
severe type, an intermediate type, and a mild type.  The syndrome is
characterized by a deficiency in the enzyme arylsulfatase B (also called
N-acetylgalactosamine-4-sulfatase), which leads to an excess of dermatan
sulfate in the urine.

In general, growth retardation occurs from 2-3 years of age, with
coarsening of facial features and abnormalities in the bones of hands and
spine.  Joint stiffness also occurs.  The intellect is usually normal.

Symptoms

Signs of Maroteaux-Lamy Syndrome usually appear between 2 and 3 years of age,
the most readily detectable symptoms being coarse facial features such as
thick nostrils and lips and development of a dwarf-like appearance.

Bone abnormalities such as large hands with stubby fingers, stiff joints,
a hunched spine, prominent chestbone, and pain in the hip bone all tend to
appear after the first 3 to 4 years.  Also evident at this time may be a
wobbly gait, resulting from inwardly pointed knees and toes.

Noisy and strained breathing, intermittent deafness and enlargement of
the liver and spleen may also occur.

Possible complications include blindness, progressive hearing loss and
excessive fluid on the brain (hydrocephalus).  (For more information, choose
"hydrocephalus" as your search term in the Rare Disease Database.)

Causes

Maroteaux-Lamy Syndrome is an autosomal recessive inherited disorder in which
a deficiency of the enzyme arylsulfatase B causes an excess of dermatan
sulfate in the urine.  (Human traits including the classic genetic diseases,
are the product of the interaction of two genes for that condition, one
received from the father and one from the mother.  In recessive disorders,
the condition does not appear unless a person inherits the same defective
gene from each parent.  If one receives one normal gene and one gene for the
disease, the person will be a carrier for the disease, but usually will show
no symptoms.  The risk of transmitting the disease to the children of a
couple, both of whom are carriers for a recessive disorder, is twenty-five
percent.  Fifty percent of their children will be carriers, but healthy as
described above.  Twenty-five percent of their children will receive both
normal genes, one from each parent and will be genetically normal.)

Affected Population

Maroteaux-Lamy Syndrome affects males and females equally.  The incidence of
this disorder is unknown.

Related Disorders

There are many types of Mucopolysaccharidoses.  For more information about
each of these disorders, choose "MPS Disorder" as your search term in the
Rare Disease Database.

DiFerrante syndrome (Mucopolysaccharidosis VIII) is a disorder described
in a single patient with clinical and biochemical features of Morquio and
Sanfilippo syndromes.  The disorder had been reported to be due to a
deficiency of glucosamine-6-sulfate sulfatase.  Subsequently, this disorder
was called MPS VIII (DiFerrante syndrome).  Dr. DiFerrante later found that
the enzyme was normal in his patient, and the disorder had been misdiagnosed.
Therefore, Diferrante syndrome is not a valid medical disorder.

The Mucolipidoses are a family of similar disorders, producing symptoms
very much like those of the Mucopolysaccharidoses (MPS).

I-cell disease, or Mucolipidosis Type II, resembles Hurler syndrome and
the two disorders are very difficult to distinguish.  I-cell disease has
similar physical and mental deterioration as MPS I, but usually occurs
earlier and is more severe.  I-cell disease is characterized by diffused
deficiency of lysosomal enzymes within the cell and is not associated with
excretion of mucopolysaccharides in the urine.

Pseudo-Hurler Polydystrophy (ML III) is also transmitted by autosomal
recessive inheritance, but it is characterized by a deficiency of multiple
lysosomal enzymes needed to break down mucopolysaccharides.  This disorder
can be identified by such symptoms as clawlike hands, somewhat coarse facial
features, dwarfism and pain in the hands.  intelligence tends to be normal in
most patients, but mild mental retardation is sometimes present.

Ganglioside Sialidase Deficiency (ML IV) is a disorder of unknown
cause characterized by early clouding of the cornea, mild to moderate mental
retardation and enlargement of liver and spleen.

(For more information about the Mucolipidoses, choose "ML Disorder" as
your search term in the Rare Disease database.)

Therapies:  Standard

Treatment of Maroteaux-Lamy Syndrome is symptomatic and supportive.  Hernias
and joint contractures may be corrected by surgery.  Physical therapy and
hearing aids may benefit patients.

Genetic counseling may be helpful to patient and family.  Prenatal
diagnosis is now possible for this disorder.

Therapies:  Investigational

Since prenatal diagnosis is now possible through amniocentesis and sampling
of a tissue layer in the embryo (chorionic villus sampling), new treatments
aimed at checking early development of Maroteaux-Lamy Syndrome are now under
study.  One method involves replacing defective enzymes via enzyme
replacement therapy and/or bone marrow transplants.  Scientific study of gene
replacement in animal models raises the hope that gene replacement may
someday be made available to people with genetic disorders such as Maroteaux-
Lamy Syndrome.

Bone marrow transplantation to treat a young girl with Maroteaux-Lamy
Syndrome greatly decreased the size of her enlarged liver and spleen, and
improved her cardiopulmonary function, joint mobility, and visual acuity.
The successful outcome of the bone marrow transplant demonstrates that toxic
compounds that accumulate in the tissues can be removed and metabolized by
transplanted cells.  However, more research is needed before this treatment
will be available for general use.

Therapies:  Investigational
The Mayo Clinic is investigating the use of Alpha Interferon as a treatment
for Maroteaux-Lamy Syndrome.  For more information, physicians can contact:

     Morie A. Gertz, M.D.
     Dept. of Hematology & Internal Medicine
     Mayo Clinic
     Rochester, MN  55905
     [phone]

This disease entry is based upon medical information available through
January 1990.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Maroteaux-Lamy Syndrome, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     MPS (Mucopolysaccharidoses) Research Funding Center, Inc.
     1215 Maxfield Road
     Hartland, MI  48029
     [phone]

     National MPS Society
     17 Kramer Street
     Hicksville, NY  11801
     [phone]

     Society of Mucopolysaccharide Diseases, Inc.
     382 Parkway Blvd.
     Flin Flon, Manitoba, Canada R8A OK4

     Society of MPS Diseases
     30 Westwood Drive
     Little Chalfont, Bucks, England

     National Digestive Diseases Information Clearinghouse
     Box NDDIC
     Bethesda, MD  20892
     [phone]

For information on genetics and genetic counseling referrals, please
contact:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

MPS Society Brochure.

MPS Research Funding Center Bulletin.

BIRTH DEFECTS COMPENDIUM, 2nd ed.; Daniel Bergsma, ed; March of Dimes,
1979.  P. 733.

MENDELIAN INHERITANCE IN MAN, 6th ed.:  Victor A. McKusick; Johns Hopkins
University Press.  1983.  P. 841.