CD-ROM Today 1996 January/CD-ROM Today 1996 January.iso/dp/0419/04191.txt

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$Unique_ID{BRK04191}
$Pretitle{}
$Title{Rieger Syndrome}
$Subject{Rieger Syndrome Goniodysgenesis-hypodontia RGS Iridogoniodysgenesis
With Somatic Anomalies Cat-Eye Syndrome Ectodermal Dysplasias Eye Anterior
Segment Dysgenesis }
$Volume{}
$Log{}

Copyright (C) 1991 National Organization for Rare Disorders, Inc.

854:
Rieger Syndrome

** IMPORTANT **
It is possible that the main title of the article (Rieger Syndrome) is
not the name you expected.  PLease check the SYNONYMS listing to find the
alternate name and disorder subdivisions covered by this article.

Synonyms

     Goniodysgenesis-hypodontia
     RGS
     Iridogoniodysgenesis With Somatic Anomalies

Information on the following diseases can be found in the Related
Disorders section of this report:

     Cat-Eye Syndrome
     Ectodermal Dysplasias
     Eye, Anterior Segment Dysgenesis

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.

Rieger Syndrome is a rare disorder in which there are facial, dental and
eye abnormalities.  This disorder is inherited as an autosomal dominant
trait.

The eye abnormalities (referred to as Rieger Eye Malformations) may be
present alone, or as a part of Rieger Syndrome.  This report will cover
Rieger Eye Malformations as well as Rieger Syndrome.  Those patients with
Rieger Eye Malformations need only refer to the portion of this report
pertaining to the eye.

Symptoms

The main symptoms of Rieger Syndrome are:

1.  Rieger Eye Malformations - a small cornea (microcornea), an opaque
ring around the outer edge of the cornea, adhesions in the front of the eye,
displacement of the pupil of the eye so that it is not centered, and/or an
underdeveloped iris.

2.  Dental Abnormalities - a congenital condition in which there are
fewer teeth than normal (hypodontia); a condition in which a single tooth,
pairs of teeth or all the teeth are smaller than normal (microdontia) and/or
cone shaped teeth.

3.  Facial Abnormalities - underdeveloped bones of the upper jaw
(hypoplasia) causing the face to have a flat appearance, a broad flat bridge
of the nose and/or a protruding lower lip.

The following conditions have been found in some patients with Rieger
Syndrome:

4.  Anal Stenosis - a small anal opening.

5.  Failure of the skin around the navel to decrease in size after birth.
This condition has reportedly been mistaken for a umbilical hernia in several
cases and unnecessary surgery was performed.

6.  Umbilical Hernia - the protrusion of intestine through a weakness in
the abdominal wall around the navel.

7.  Glaucoma - disease of the eye in which there is increased pressure
within the eyeball.  This disease can result in damage to the optic disk and
gradual loss of vision.  The defects in the angle of the eye that is created
by the iris and cornea (trabeculum), the vein at the corner of the eye that
drains the water in the eye into the bloodstream (schlemm) and the adhesions
associated with Rieger Syndrome can lead to glaucoma.

The following conditions have sometimes occurred in conjunction with
Rieger Syndrome but researchers cannot agree as to whether they are separate
entities in which the Rieger Eye Malformations are present.

1.  Myotonic Dystrophy - a chronic progressive disease that causes
atrophy of the muscles, failing vision, slurred speech, droopy eyelids and
general muscle weakness.  (For more information on this disorder choose
"Myotonic Dystrophy" as your search term in the Rare Disease Database).

2.  Conductive Deafness - a type of hearing loss in which sound does not
travel well to the sound organs of the inner ear.

3.  Myotonia - a condition in which the muscles do not relax after
contracting.

4.  Mental Retardation - less than average intellectual function with
problems in learning and social behavior.

Causes

Rieger Syndrome is inherited as an autosomal dominant trait.  Human traits
including the classic genetic diseases, are the product of the interaction of
two genes, one received from the father and one from the mother.

In dominant disorders a single copy of the disease gene (received from
either the mother or father) will be expressed "dominating" the other normal
gene and resulting in the appearance of the disease.  The risk of
transmitting the disorder from affected parent to offspring is fifty percent
for each pregnancy regardless of the sex of the resulting child.

Affected Population

Rieger Syndrome is a rare disorder that affects males and females in equal
numbers.  This disorder can be detected during the first month of life when
the eye defects are visible.  When the eye defects are not visible during the
first month of life, the disorder is usually detected in early childhood when
the eye and dental defects become apparent.

Related Disorders

Symptoms of the following disorders can be similar to those of Rieger
Syndrome Comparisons may be useful for a differential diagnosis:

Cat-Eye Syndrome is a rare disorder in which there is a cleft along the
eyeball affecting the iris, the membrane that covers the white of the eyeball
(choroid), and/or the retina causing a vertical pupil;  small growths or
polyps, pits and abnormal passages near the front of the outer ear; and
absence of the opening, duct or canal of the anus.  Other symptoms of this
disorder that may be present in some patients are:  mild mental deficiency,
heart defects such as tetralogy of Fallot ( lung narrowing, a defect in the
wall of the lower chamber of the heart, a defect in the position of the aorta
and enlargement of the right ventricle) and an abnormality of the large blood
vessels that return blood from the lungs to the heart.  There may also be an
abnormally wide space between the eyes, and absence of a kidney on one side.
This disorder may be inherited as an autosomal dominant trait or its genetic
transmission may be unknown in many cases.

Ectodermal Dysplasias are a group of hereditary, nonprogressive syndromes
in which the affected tissue derives primarily from the ectodermal germ
layer.  The skin, its derivatives, and some other organs are involved.  A
predisposition to respiratory infections, due to a somewhat depressed immune
system and to defective mucous glands in parts of the respiratory tract, is
the most life threatening characteristic of this group of disorders.
Symptoms include eczema, poorly functioning sweat glands, sparse or absent
hair follicles, abnormal hair, disfigured nails, and difficulties with the
nasal passages and ear canals.  Skin is satiny smooth, prone to rashes, and
slow to heal.  (For more information on this disorder choose "Ectodermal
Dysplasia" as your search term in the Rare Disease Database).

Eye, Anterior Segment Dysgenesis is a rare congenital disorder in which
there is abnormal tissue development of the outer eye segment or, in less
severe cases, the back of the outer surface of the cornea is nontransparent
(embryotoxin).  This disorder may cause glaucoma, cataracts, partial or
total dislocation of the lenses, atrophy of the eyeball, or a lack of
transparency of the cornea.  Malformations of the teeth, abdominal wall,
skeleton, and heart may also be associated with this disorder.  Peter's plus
(a condition that consists of short stature, mental retardation, abnormal
ears, and clefting of the palate and/or lip) is another condition that is
sometimes associated with Eye, Anterior Segment Dysgenesis.  An autosomal
dominant inheritance is found in many cases of Eye, Anterior Segment
Dysgenesis even though the disorder can vary greatly from one member of a
family to another.  When Peter's plus is present an autosomal recessive
inheritance is the form of transmission.

Therapies:  Standard

Treatment of Rieger Syndrome is symptomatic and supportive.  Drug therapy is
the primary treatment for glaucoma, usually consisting of a topical beta
blocker in the form of eye drops.  Laser surgery is usually reserved for
those patients in which the pressure in the eye is not relieved by
medications.

Prostheses (false teeth) are used for dental malformations.

Genetic counseling may be of benefit for patients and their families.

Therapies:  Investigational

This disease entry is based upon medical information available through June
1991.  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 Rieger Syndrome, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     203-746-6518

     National Foundation for Ectodermal Dysplasia
     219 E. Main Street
     Mascoutah, IL  62258
     [phone]

     Vision Foundation, Inc.
     818 Mt. Auburn Street
     Watertown, MA  02172
     [phone]

     National Association for Parents of the Visually Impaired, Inc.
     P.O. Box 180806
     Austin, TX  78718
     [phone]

     National Association for the Visually Handicapped
     22 W. 21st Street, Sixth Floor
     New York, New York  10010
     [phone]

     NIH/National Eye Institute
     9000 Rockville Pike
     Bethesda, MD  20892
     301-496-5248

For Genetic Information and Genetic Counseling Referrals, please contact:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY 10605
     914-428-7100

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

References

MENDELIAN INHERITANCE IN MAN, 9th Ed.:  Victor A. McKusick, Editor:  Johns
Hopkins University Press, 1990.  Pp. 843-44.

SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.:  Kenneth L.
Jones, M.D., Editor; W.B. Saunders Co., 1988.  Pp. 532-33.

BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief;
Blackwell Scientific Publications, 1990.  Pp. 1497.

DIAGNOSTIC RECOGNITION OF GENETIC DISEASE, William Nyhan, et al.; Lea &
Febiger, 1987.  Pp. 226-27.

THE RIEGER SYNDROME AND A CHROMOSOME 13 DELETION:  R.A. Stathacopoulos,
et al.; J Pediatr Opthalmol Strabismus (Jul-Aug 1987, issue 24 (4)).  Pp.198-
203.

BONE AND JOINT MANIFESTATIONS OF RIEGER SYNDROME:  A REPORT OF A FAMILY:
T. Koshino, et al.; J Pediatr Orthop (Mar-Apr 1989, issue 9(2)).  Pp.  2240-
30.