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$Unique_ID{BRK04305}
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$Title{Usher's Syndrome}
$Subject{Usher's Syndrome Hereditary Deafness-Retinitis Pigmentosa Retinitis
Pigmentosa and Congenital Deafness Type I Usher Type II Usher Type III Usher
Type IV Usher Retinitis Pigmentosa Hallgren Syndrome Alstrom Syndrome Rubella}
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Copyright (C) 1989, 1990 National Organization for Rare Disorders, Inc.

529:
Usher's Syndrome

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

Synonyms

     Hereditary Deafness-Retinitis Pigmentosa
     Retinitis Pigmentosa and Congenital Deafness

DISORDER SUBDIVISIONS:

     Type I Usher
     Type II Usher
     Type III Usher
     Type IV Usher

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

     Retinitis Pigmentosa
     Hallgren Syndrome
     Alstrom Syndrome
     Rubella

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.

Usher's Syndrome is a genetic disorder primarily characterized by
deafness accompanied by Retinitis Pigmentosa, a disorder that causes
progressive loss of vision.  The age at which the disorder appears as well as
severity of symptoms distinguishes the four types of Usher's Syndrome.

Symptoms

Usher's Syndrome is characterized by nerve deafness (sensorineural hearing
loss) as well as Retinitis Pigmentosa, a disorder that causes degeneration of
the retina leading to progressive loss of vision.  The nerve deafness may be
complete or mild, and usually does not progress.  The Retinitis Pigmentosa
can begin during childhood or later in life.  Studies show that clear central
vision may be maintained for many years even while side (peripheral) vision
decreases.  In some cases, these symptoms may be accompanied by mental
deficiencies, psychosis, disturbances in walking related to inner ear
problems, or cataracts.

Type I Usher's Syndrome is characterized by complete hearing loss at
birth, vision problems beginning at approximately the age of ten, development
of night blindness at approximately twenty years of age, and progressive loss
of peripheral vision.

Type II Usher's Syndrome is identified by moderate to complete hearing
loss at birth, and the onset of Retinitis Pigmentosa during the late teens or
early twenties.  Night blindness usually begins during the late twenties or
thirties.

Type III Usher's Syndrome usually begins at puberty with progressive
hearing loss.  Retinitis Pigmentosa begins much later in life.

Type IV Usher's Syndrome predominately affects males and is also
characterized by hearing loss and progressive vision disturbances.  This is
an extremely rare form of Usher's Syndrome and is thought to be inherited as
an X-Linked trait.

Causes

Usher's Syndrome is inherited as an autosomal recessive trait in types I, II
and III.  Type IV Usher's Syndrome is thought to be inherited as an X-Linked
recessive trait.

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.

X-linked recessive disorders are conditions which are coded on the X
chromosome.  Females have two X chromosomes, but males have one X chromosome
and one Y chromosome.  Therefore in females, disease traits on the X
chromosome can be masked by the normal gene on the other X chromosome.  Since
males have only one X chromosome, if they inherit a gene for a disease present
on the X, it will be expressed.  Men with X-linked disorders transmit the gene
to all their daughters, who are carriers, but never to their sons.  Women who
are carriers of an X-linked disorder have a fifty percent risk of transmitting
the carrier condition to their daughters, and a fifty percent risk of
transmitting the disease to their sons.

The exact reason for the hearing and vision loss in Usher's Syndrome is
not well understood.  Persons with Usher Syndrome may have a hypersensitivity
to compounds which could damage chromosomal components known as DNA.  This
suggests a defective DNA repair mechanism.  Immune system disturbances are
also thought to be associated with Usher Syndrome, although the exact process
is not well understood.

In 1989 researchers discovered the chromosome marker for Type II Usher
Syndrome.  This is expected to lead to the isolation of the genes that cause
this disorder, identification of gene carriers, and perhaps, prenatal tests.

Affected Population

Usher's Syndrome affects approximately five to ten in 100,000 people
worldwide.  Higher than normal numbers of people with Usher's Syndrome have
been found among Jewish people in Berlin, Germany; French Canadians of
Louisiana; Argentineans of Spanish descent; and Nigerian Africans.

Related Disorders

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

Hallgren Syndrome is also known as Graefe-Sjogren Syndrome.  Deafness at
birth is accompanied by progressive vision impairment including nystagmus and
cataracts.  Additional symptoms are psychomotor retardation,
vestibulocerebellar ataxia, mental deficiency and psychosis.

Alstrom Syndrome is an inherited disorder characterized by retinal
degeneration with nystagmus and loss of central vision.  This disorder is
associated with obesity in childhood.  Nerve deafness and Diabetes Mellitus
tend to develop after the age of ten years.

Rubella is more commonly known as German measles.  This acute viral
disorder is of concern when contracted during the first three months of
pregnancy because it can cause fetal abnormalities.  These abnormalities may
include hearing loss and/or vision disturbances as well as developmental
malformations.  (For more information on this disorder, choose "Measles" as
your search term in the Rare Disease Database).

The following disorder is associated with Usher's Syndrome as a symptom
complex.  It is not necessary for a differential diagnosis because it may
start years after onset of nerve deafness.

Retinitis Pigmentosa (RP) is one of a group of inherited eye diseases
causing degeneration of the retina.  When the retina degenerates, as in RP,
the vision decreases and may occasionally be lost.  Retinitis Pigmentosa may
be associated with other symptoms such as central nervous system disorders,
metabolic disorders and even chromosomal abnormalities such as Turner's
Syndrome.  (For more information on these disorders, choose "RP" and "Turner"
as your search terms in the Rare Disease Database.)

Therapies:  Standard

Treatment of Usher's Syndrome is symptomatic and supportive.  Agencies which
provide services to individuals with hearing and vision loss can be helpful.
Surgery to remove cataracts in conjunction with intraocular lens implantation
may improve vision problems in some cases.  Genetic counseling is recommended
for patients and their families.

It is important to identify as early as possible whether a deaf child may
have Usher's Syndrome.  If vision loss occurs later in life, teaching a child
sign language may have little value as a communication aid during adulthood.
Therefore, educational methods and options should be chosen carefully during
school years.

Therapies:  Investigational

Scientists are currently studying Usher's Syndrome to identify the location
of the defective gene and a chromosomal marker.  Once this gene is
identified, researchers may then be able to develop effective treatment.

This disease entry is based upon medical information available through
May 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 Usher's Syndrome, please contact:

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

     RP Foundation Fighting Blindness
     1401 Mt. Royal Avenue
     Baltimore, MD  21217
     [phone]
     [phone]

     Alexander Graham Bell Association for the Deaf
     3417 Volta, NW
     Washington, DC  20007
     [phone]

     For Trained Hearing Dogs:
     American Humane Association
     P.O. Box 1266
     Denver, CO  80201

     Deafness Research Foundation
     55 East 34th Street
     New York, NY  10016
     [phone]

     National Information Center on Deafness
     Gallaudet College
     Kendall Green
     Washington, DC  20002
     voice & tdd phone [phone]

     American Society for Deaf Children
     814 Thayer Avenue
     Silver Spring, MD  20910
     [phone]  Voice/TTY

     NIH/National Eye Institute
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]

     NIH/National Institute of Deafness & Other Communication Disorders
     (NIDCD)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]

     National Federation of the Blind
     1800 Johnson Street
     Baltimore, MD  21230
     [phone]
     1-800-638-7518

     American Council of the Blind, Inc. (ACB)
     1155 - 15th St., NW, Suite 720
     Washington, D.C.  20005
     [phone]
     [phone]

     American Foundation for the Blind (AFB)
     15 W. 16th St.
     New York, NY  10011
     [phone]
     Regional offices:
     Atlanta, GA  [phone]
     Chicago, IL  [phone]
     Dallas, TX  [phone]
     San Francisco, CA  [phone]

For genetic information 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

This Rare Disease Database entry is based upon outlines prepared by medical
and dental students (1984-1986) at the Medical College of Virginia for their
course in human genetics, and the following articles:

MENDELIAN INHERITANCE IN MAN, 7th ed.:  Victor A. McKusick; Johns Hopkins
University Press, 1986.  Pp.  1293, 1450.

FIGHTING BLINDNESS NEWS, RP Foundation Fighting Blindness; Winter 1987-
1988 Newsletter.  Pp. 2-4.

RADIATION SENSITIVITY OF FIBROBLAST STRAINS FROM PATIENTS WITH USHER'S
SYNDROME, DUCHENNE MUSCULAR DYSTROPHY, AND HUNTINGTON'S DISEASE:  J. Nove, et
al.;  Mutat Res (July 1987, issue 184(1) ).  Pp. 29-38.

USHER'S SYNDROME.  OPHTHALMIC AND NEURO-OTOLOGIC FINDINGS SUGGESTING
GENETIC HETEROGENEITY:  G.A. Fishman, et al.; Arch Ophthalmol (September 1983,
issue 101(9) ).  Pp. 1367-74.

CATARACT EXTRACTION AND INTRAOCULAR LENS IMPLANTATION IN PATIENTS WITH
RETINITIS PIGMENTOSA OR USHER'S SYNDROME:  D.A. Newsome, et al.; Arch
Ophthalmol (June 1986, issue 104(6)).  Pp. 852-854.